JP2005290548A - Titanium alloy superior in high-temperature oxidation resistance and corrosion resistance - Google Patents
Titanium alloy superior in high-temperature oxidation resistance and corrosion resistance Download PDFInfo
- Publication number
- JP2005290548A JP2005290548A JP2005026474A JP2005026474A JP2005290548A JP 2005290548 A JP2005290548 A JP 2005290548A JP 2005026474 A JP2005026474 A JP 2005026474A JP 2005026474 A JP2005026474 A JP 2005026474A JP 2005290548 A JP2005290548 A JP 2005290548A
- Authority
- JP
- Japan
- Prior art keywords
- resistance
- titanium alloy
- test
- corrosion
- temperature oxidation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000007797 corrosion Effects 0.000 title claims abstract description 94
- 238000005260 corrosion Methods 0.000 title claims abstract description 94
- 229910001069 Ti alloy Inorganic materials 0.000 title claims abstract description 85
- 230000003647 oxidation Effects 0.000 title claims abstract description 74
- 238000007254 oxidation reaction Methods 0.000 title claims abstract description 74
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 50
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 47
- 239000000463 material Substances 0.000 claims description 35
- 239000000956 alloy Substances 0.000 claims description 21
- 229910045601 alloy Inorganic materials 0.000 claims description 16
- 238000007747 plating Methods 0.000 claims description 11
- 229910052804 chromium Inorganic materials 0.000 claims description 6
- 229910052735 hafnium Inorganic materials 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 6
- 229910052715 tantalum Inorganic materials 0.000 claims description 6
- 229910052721 tungsten Inorganic materials 0.000 claims description 6
- 229910052726 zirconium Inorganic materials 0.000 claims description 6
- 239000000654 additive Substances 0.000 claims description 5
- 230000000996 additive effect Effects 0.000 claims description 5
- 230000001965 increasing effect Effects 0.000 abstract description 9
- 229910052758 niobium Inorganic materials 0.000 abstract description 5
- 238000012360 testing method Methods 0.000 description 62
- 239000010936 titanium Substances 0.000 description 41
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 38
- 229910052719 titanium Inorganic materials 0.000 description 38
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 31
- 229910052760 oxygen Inorganic materials 0.000 description 31
- 239000001301 oxygen Substances 0.000 description 31
- 238000009792 diffusion process Methods 0.000 description 28
- 230000000694 effects Effects 0.000 description 26
- 239000013078 crystal Substances 0.000 description 24
- 230000015572 biosynthetic process Effects 0.000 description 14
- 238000000137 annealing Methods 0.000 description 11
- 238000011156 evaluation Methods 0.000 description 11
- 239000000203 mixture Substances 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 10
- 238000005098 hot rolling Methods 0.000 description 8
- 230000006872 improvement Effects 0.000 description 8
- 230000009467 reduction Effects 0.000 description 8
- 230000002411 adverse Effects 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000009864 tensile test Methods 0.000 description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 238000000465 moulding Methods 0.000 description 6
- 230000001590 oxidative effect Effects 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 238000005275 alloying Methods 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- 238000005097 cold rolling Methods 0.000 description 4
- 238000000227 grinding Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000002791 soaking Methods 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- 229910000838 Al alloy Inorganic materials 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 3
- 229910004349 Ti-Al Inorganic materials 0.000 description 3
- 229910004692 Ti—Al Inorganic materials 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000003584 silencer Effects 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 229910021364 Al-Si alloy Inorganic materials 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910000676 Si alloy Inorganic materials 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000005219 brazing Methods 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 235000013619 trace mineral Nutrition 0.000 description 2
- 239000011573 trace mineral Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 229910018575 Al—Ti Inorganic materials 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 206010053759 Growth retardation Diseases 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000883 Ti6Al4V Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 231100000989 no adverse effect Toxicity 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 229910021332 silicide Inorganic materials 0.000 description 1
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 description 1
- 238000009751 slip forming Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
Abstract
Description
本発明は、特に耐高温酸化性と耐食性に優れ、例えば自動車用やバイク（自動二輪）用のマフラー材などとして有用なチタン合金材に関するものであり、より詳細には、チタン合金本来の優れた強度特性や耐食性を有しつつ、且つコストや加工性を損なうことなく、特に高温での耐酸化特性と耐食性を高めたチタン合金に関するものである。 The present invention relates to a titanium alloy material that is particularly excellent in high-temperature oxidation resistance and corrosion resistance, and is useful, for example, as a muffler material for automobiles and motorcycles (motorcycles). The present invention relates to a titanium alloy that has strength characteristics and corrosion resistance, and has improved oxidation resistance characteristics and corrosion resistance particularly at high temperatures without impairing cost and workability.
なお本発明のチタン合金は、その優れた耐高温酸化性と耐食性を活かし、高温の酸化性雰囲気や腐食環境に曝される様々の用途に広く活用できるが、本明細書では特にマフラー材として使用する場合を主体にして説明する。 The titanium alloy of the present invention can be widely used for various applications exposed to high-temperature oxidizing atmospheres and corrosive environments, taking advantage of its excellent high-temperature oxidation resistance and corrosion resistance. The description will be made mainly on the case of doing so.
自動車やバイクの排気系は、エンジンの排ガス出口側から順にエキゾーストマニホールド→エキゾーストパイプ→触媒マフラー→プリマフラー→サイレンサー（メインマフラー）等によって構成されている（本明細書では、これら個々の部材および全体をマフラーと総称する）。これらマフラーの構成素材としては普通鋼が使用されていたが、近年では耐食性に優れたステンレス鋼が主流となっている。 The exhaust system of automobiles and motorcycles is composed of an exhaust manifold, an exhaust pipe, a catalyst muffler, a pre-muffler, a silencer (main muffler), etc. in order from the exhaust gas outlet side of the engine. Are collectively referred to as mufflers). As the constituent material of these mufflers, ordinary steel has been used, but in recent years, stainless steel having excellent corrosion resistance has become mainstream.
しかし、最近バイクを中心としてチタン製マフラーが注目されており、従来の普通鋼やステンレス鋼に比べて軽量で且つ振動疲労に対する耐久性が良好で耐食性にも優れ、更には熱膨張率が小さく耐熱疲労特性にも優れているといった様々の特性を有していることから、レース用バイクをはじめとして量産バイクにもＴｉ製マフラーを標準装備する例が増大している。 Recently, however, titanium mufflers have attracted attention, especially in motorcycles. They are lighter than conventional ordinary steel and stainless steel, have better durability against vibration fatigue, have better corrosion resistance, and have a low thermal expansion coefficient and heat resistance. Since it has various characteristics such as excellent fatigue characteristics, there are an increasing number of cases in which Ti mufflers are standard equipment on racing motorcycles and mass production motorcycles.
ところで、現在実用化されているチタン製マフラーの殆どは、ＪＩＳ２種の工業用純チタンである。ちなみに、自動車やバイクエンジン等から放出される排気ガス温度は通常７００℃程度以上になると予測されるが、バイク用マフラーの如く表面が外気に大きく開放されている場合は、表面から熱が外気へ放散されるためマフラー自体の温度はそれほど上がらず、ＪＩＳ２種の純チタン材でも支障なく使用できる。ところが、外気に直接開放されていない自動車用マフラー、あるいはバイク用マフラーでもエキゾーストパイプや複数のエキゾーストパイプが合流する部分に配置される部材は高温になり易いため、現状のＪＩＳ２種純チタン材よりも高耐熱性のチタン合金材が望まれる。 By the way, most of the titanium mufflers currently in practical use are JIS type 2 industrial pure titanium. By the way, the exhaust gas temperature emitted from automobiles, motorcycle engines, etc. is usually predicted to be about 700 ° C. or higher. However, when the surface is widely open to the outside air like a muffler for motorcycles, the heat is transferred from the surface to the outside air. Since it is diffused, the temperature of the muffler itself does not rise so much, and even JIS type 2 pure titanium material can be used without any problem. However, even in automobile mufflers or motorcycle mufflers that are not directly open to the outside air, the members that are arranged in the exhaust pipe and the part where the plurality of exhaust pipes join are likely to become hot, so they are more than the current JIS class 2 pure titanium material. A highly heat resistant titanium alloy material is desired.
こうした観点からすると、既存のチタン合金のうちＴｉ−３Ａｌ−２．５ＶやＴｉ−６Ａｌ−４Ｖなどのチタン合金は有望なマフラー用素材になり得ると考えられる。ところが、マフラーに成形して組み立てるには素材を薄板化する必要があり、加工性にも優れたものでなければならないため、成形加工性に欠ける上記２種の既存チタン合金では要求を満たすことができない。 From such a viewpoint, it is considered that titanium alloys such as Ti-3Al-2.5V and Ti-6Al-4V among existing titanium alloys can be promising materials for mufflers. However, in order to form and assemble the muffler, it is necessary to make the material thin, and it must be excellent in workability. Therefore, the above-mentioned two existing titanium alloys lacking in workability can meet the requirements. Can not.
そこで本出願人は、優れた耐熱性や耐食性を有すると共に成形加工性にも優れたチタン合金の開発を期してかねてより研究を進めており、その成果の一環として先に特許文献１に記載のチタン合金を開発した。 Therefore, the present applicant has been further researching for the development of a titanium alloy that has excellent heat resistance and corrosion resistance and is excellent in moldability, and as a part of the results, described in Patent Document 1 above. Developed titanium alloy.
このチタン合金は、Ａｌ含量を質量基準で０．５〜２．３％の範囲に定め、好ましくは金属組織をα相：９０体積％以上、β相：１０体積％以下とすることによって、チタン合金本来の軽量性や耐食性を留保しつつ耐熱性や耐酸化性を高めると共に、マフラー素材として重要な成形加工性を高めたもので、有用なマフラー素材として期待できる。 This titanium alloy has an Al content in the range of 0.5 to 2.3% on a mass basis, and preferably has a metal structure of α phase: 90% by volume or more and β phase: 10% by volume or less. While maintaining the original light weight and corrosion resistance of the alloy, it has improved heat resistance and oxidation resistance, and has improved moldability, which is important as a muffler material, and can be expected as a useful muffler material.
ところが本発明者らが更に研究を進めるうち、該特許文献１に開示したチタン合金は、耐食性（特に、耐すきま腐食性）や耐高温酸化性において尚改善の余地を残していることが確認された。即ちこのチタン合金は、成形加工性と高温強度を両立させるためＡｌ含量を上記範囲に規定しているが、実用性を考慮するとＡｌ含量を１．５％程度以上にするのが好ましいと考えられていた。ところがこのレベルのＡｌ含量では、より厳しい腐食環境や高温酸化性雰囲気に曝されたときの耐久性に限界があり、今後の需要者の要望を考慮すると更なる改善が望まれる。 However, as the inventors proceeded further research, it was confirmed that the titanium alloy disclosed in Patent Document 1 still has room for improvement in corrosion resistance (particularly crevice corrosion resistance) and high-temperature oxidation resistance. It was. That is, in this titanium alloy, the Al content is specified in the above range in order to achieve both formability and high temperature strength, but considering practicality, it is considered preferable to make the Al content about 1.5% or more. It was. However, at this level of Al content, there is a limit to the durability when exposed to a more severe corrosive environment or high-temperature oxidizing atmosphere, and further improvements are desired in consideration of future customer demands.
また本発明者らは、チタン合金に関する他の改善技術として特許文献２に開示の発明も提案している。この発明は、最近需要が急増している眼鏡用フレームを主たる用途として適用されるもので、Ａｌ含量は上記と同レベルの０．５〜２．３％であり、β安定化元素を実質的に含有させることなく、４％以下のＧａや１％以下のＳｉを含有させることによって冷間加工性とロウ付け後の疲労特性を高めたものである。この発明では、Ａｌ含量の上限を２．３％に制限することによって安定した成形加工性を確保しつつ、Ｓｉ添加による微細なＴｉシリサイドの生成によってロウ付け後の結晶粒の成長を抑制し、疲労強度を高めている。しかしこのチタン合金は、その主たる用途が眼鏡用フレームの如く常温環境下で使用されるものであり、マフラー用素材の如く苛酷な腐食環境や高温酸化性雰囲気で使用される本発明のチタン合金とは異種の合金に属する。
本発明者らは上記の様な公知技術を踏まえ、特に前掲の特許文献１として開示したチタン合金を更に進化させ、該チタン合金が有する特徴を備えた上で、特に耐高温酸化性と耐食性の一段と改善されたチタン合金を提供することにある。 In light of the above-described known techniques, the present inventors have further evolved the titanium alloy disclosed in Patent Document 1 described above, and provided the characteristics of the titanium alloy, and in particular, high temperature oxidation resistance and corrosion resistance. It is to provide a further improved titanium alloy.
上記課題を解決することのできた本発明に係る耐高温酸化性および耐食性に優れたチタン合金は、質量基準でＡｌ：０．３０〜１．５０％と、Ｓｉ：０．１０〜１．０％を、好ましくはＳｉ／Ａｌの質量比で１／３以上含有するところに特徴を有している。本発明のチタン合金は、他の元素としてＮｂ：０．１〜０．５％を含有するものであってもよく、更には、Ｔａ，Ｗ，Ｍｏ，Ｃｒ，Ｚｒ，Ｈｆよりなる群から選択される少なくとも１種の元素を含むものであってもよいが、それら添加合金元素の含有量は、前記Ａｌ，Ｓｉ，Ｎｂを含めた総含有量で２．５％以下に抑えることが望ましい。 The titanium alloy excellent in high-temperature oxidation resistance and corrosion resistance according to the present invention that has solved the above-mentioned problems is Al: 0.30-1.50% and Si: 0.10-1.0% on a mass basis. Is preferably contained in a mass ratio of Si / Al of 1/3 or more. The titanium alloy of the present invention may contain Nb: 0.1 to 0.5% as another element, and further selected from the group consisting of Ta, W, Mo, Cr, Zr, and Hf. However, it is desirable that the content of these additive alloy elements is suppressed to 2.5% or less in terms of the total content including Al, Si, and Nb.
本発明のチタン合金は、それ自身で優れた耐高温酸化性を有しているが、該チタン合金の表面に、Ａｌ系めっきを形成すれば、高温耐酸化性を一段と優れたものにできるので好ましい。 The titanium alloy of the present invention itself has excellent high temperature oxidation resistance. However, if an Al-based plating is formed on the surface of the titanium alloy, the high temperature oxidation resistance can be further improved. preferable.
かくして得られる本発明のチタン合金は、高温の酸化性雰囲気や苛酷な腐食環境に曝される様々の部材として有効に活用することができ、具体的には、自動車用や自動二輪用のマフラー［エキゾーストマニホールド、エキゾーストパイプ、触媒マフラー、プリマフラー、サイレンサー（メインマフラー）など個々のマフラー部品などを含む］として極めて有用であり、更には船舶用マフラー、工場の排ガスダクト、煙突・煙道の内張り材などとしても有用である。 The titanium alloy of the present invention thus obtained can be effectively used as various members exposed to high-temperature oxidizing atmospheres and severe corrosive environments. Specifically, mufflers for automobiles and motorcycles [ It is extremely useful as an exhaust manifold, exhaust pipe, catalyst muffler, pre-muffler, silencer (main muffler) and other individual muffler parts. It is also useful as such.
本発明のチタン合金は、従来のチタン合金に比べて相対的にＡｌ含量を低減すると共に少量のＳｉやＮｂを含有させ、耐食性の更なる向上と、従来材を凌駕する卓越した耐高温酸化性を与えたもので、チタン合金マフラー材の品質を一段と高めると共に、マフラー部材以外の用途においても、例えば船舶用マフラー、工場の排ガスダクト、煙突・煙道の内張り材の如く、高温の苛酷な酸化性雰囲気や腐食性雰囲気に曝される様々の部材として有効に活用できる。 The titanium alloy of the present invention has a relatively low Al content and a small amount of Si and Nb as compared with conventional titanium alloys, further improving corrosion resistance, and superior high-temperature oxidation resistance that surpasses conventional materials. In addition to improving the quality of titanium alloy muffler materials, in applications other than muffler members, high-temperature severe oxidation such as marine mufflers, factory exhaust ducts, chimney / flue lining materials, etc. It can be effectively used as various members exposed to corrosive atmosphere and corrosive atmosphere.
本発明者らは、上記背景技術で指摘した様な状況の下で、従来からマフラー用素材として使われてきた純チタンはもとより、前記特許文献１として提示したチタン合金をも凌駕する性能のチタン合金を開発すべく、性能評価基準に立ち返って検討を進めた。その理由は下記の通りである。 Under the circumstances as pointed out in the background art, the present inventors have not only pure titanium conventionally used as a material for mufflers, but also titanium having performance superior to that of the titanium alloy presented as Patent Document 1. In order to develop an alloy, we went back to the performance evaluation criteria and proceeded with the study. The reason is as follows.
すなわち、前記特許文献１に開示の発明で耐酸化性の評価法として採用しているのは、７００℃で２０時間もしくは４０時間保持した後の酸化増量であり、該酸化増量の大小によって耐酸化性の優劣を評価している。ところが、試験温度が７００℃を超える高温になると酸化スケールの生成が激しくなり、厚く成長したスケールが剥離することでスケールロスが起こり、酸化による重量はむしろ減少するため、酸化増量で耐高温酸化性を評価することはできない。また、７００℃以上の高温になると、酸化スケールの生成が激しくなると共に酸素が金属チタン中へ拡散侵入し、硬くて脆弱な酸素拡散層が形成される（酸素拡散層の酸素濃度があるレベルを超えると酸化スケールになる）が、酸化増量では該酸素拡散層の形成状態を把握できない。更に加えて、試験温度が７００℃を超えると結晶粒の成長が顕著となり、これが進むと脆化や疲労強度の低下につながる。 That is, the oxidation resistance evaluation method employed in the invention disclosed in Patent Document 1 is an increase in oxidation after being held at 700 ° C. for 20 hours or 40 hours, and the oxidation resistance depends on the size of the increase in oxidation. Assessing superiority or inferiority of sex. However, when the test temperature exceeds 700 ° C, the generation of oxidized scale becomes severe, and scale loss occurs due to peeling of the thickly grown scale, and the weight due to oxidation is rather reduced. Cannot be evaluated. Also, when the temperature is higher than 700 ° C., the generation of oxide scale becomes intense and oxygen diffuses and penetrates into the titanium metal, forming a hard and fragile oxygen diffusion layer (the oxygen concentration of the oxygen diffusion layer is at a certain level). If it exceeds, it becomes an oxide scale), but the formation state of the oxygen diffusion layer cannot be grasped by increasing the oxidation amount. In addition, when the test temperature exceeds 700 ° C., the growth of crystal grains becomes remarkable, and as this progresses, embrittlement and fatigue strength decrease.
従って耐酸化性の評価には、酸化増量やスケールロス、酸素拡散層の形成度合いに加えて、結晶粒の成長状態も考慮に入れる必要がある。 Therefore, in the evaluation of oxidation resistance, it is necessary to take into consideration the growth state of crystal grains in addition to the increase in oxidation, the scale loss, and the degree of formation of the oxygen diffusion layer.
すなわち本発明が意図する苛酷な高温酸化性雰囲気を想定して、より実用にマッチした性能評価を行なうには、1)供試チタン合金板の穴空きに直結するスケールロスによる板厚減少、2)強度劣化に直結する酸素拡散層の形成状態、3)チタン合金板の脆化と疲労強度劣化に直結する結晶粒の粗大化、等を定量的に把握することのできる試験法を確立する必要がある。 In other words, assuming a severe high-temperature oxidizing atmosphere intended by the present invention, in order to perform performance evaluation more suitable for practical use, 1) thickness reduction due to scale loss directly connected to the hole in the test titanium alloy plate, 2 It is necessary to establish a test method that can quantitatively grasp the formation state of the oxygen diffusion layer directly connected to the strength deterioration, 3) the brittleness of the titanium alloy sheet and the coarsening of the crystal grains directly connected to the fatigue strength deterioration. There is.
そこで、従来の純チタン材や前記特許文献１に開示されたチタン合金などとの差別化を明確にするため、下記の高温耐酸化性評価法を定めた。 Therefore, the following high-temperature oxidation resistance evaluation method was defined in order to clarify differentiation from the conventional pure titanium material and the titanium alloy disclosed in Patent Document 1.
［耐スケールロス性］
厚さ約１ｍｍの供試チタン合金板（長さ１００ｍｍ、幅１０ｍｍ）を、内部を空気組成に保った加熱炉に装入し、８００℃で１００時間保持した後、試料断面を光学顕微鏡で観察する。
[Scale loss resistance]
A test titanium alloy plate (length: 100 mm, width: 10 mm) having a thickness of about 1 mm was placed in a heating furnace maintained at an air composition inside, held at 800 ° C. for 100 hours, and the sample cross section was observed with an optical microscope. To do.
光学顕微鏡での観察は、通常の断面ミクロ組織を観察するのと同様に、試料断面が観察できる向きに試料を樹脂に埋め込んだ後、試料断面を鏡面研磨する。そして、この様に処理した試験片の断面を光学顕微鏡で観察したときに、白っぽく見える部分、即ち金属の部分（表面に形成された酸化スケールに相当する部分は暗い灰色に見えるので、金属部分と酸化スケールの部分は明瞭に区別できる）の板厚（Ｘ1）を測定し、高温酸化前の板厚（Ｘ0）に対する減少量から下記式によって板厚減少率を求め、測定箇所１０箇所の平均値として耐スケールロス性を評価する。
板厚減少率（％）＝［（Ｘ0−Ｘ1）／Ｘ0］×１００。
In the observation with an optical microscope, the sample cross section is mirror-polished after the sample is embedded in the resin in the direction in which the sample cross section can be observed in the same manner as in observing a normal cross-sectional microstructure. When the cross section of the test piece treated in this way is observed with an optical microscope, the portion that appears whitish, that is, the metal portion (the portion corresponding to the oxide scale formed on the surface appears dark gray, The thickness (X 1 ) of the oxide scale can be clearly distinguished), and the thickness reduction rate is obtained from the amount of reduction relative to the thickness (X 0 ) before high-temperature oxidation by the following formula. Scale loss resistance is evaluated as an average value.
Sheet thickness reduction rate (%) = [(X 0 −X 1 ) / X 0 ] × 100.
［耐酸素拡散層形成性］
厚さ約１ｍｍの供試チタン合金板（長さ１００ｍｍ、幅１０ｍｍ）を、内部を空気組成に保った加熱炉に装入し、８００℃で１００時間保持した後、該供試板を中央部で切断し、該切断面における金属チタン合金部分の表面から１０μｍの深さ位置のマイクロビッカース硬さ（Ｈｖ）を、測定箇所１０の平均値として求め、耐酸素拡散層形成性を評価する。得られたビッカース硬さＨｖの値が小さいほど耐酸素拡散層形成性は良好と判断できる。
[Oxygen diffusion layer formation]
A test titanium alloy plate (length: 100 mm, width: 10 mm) having a thickness of about 1 mm was placed in a heating furnace maintained at an air composition inside and kept at 800 ° C. for 100 hours. Then, the micro Vickers hardness (Hv) at a depth position of 10 μm from the surface of the metal titanium alloy portion on the cut surface is obtained as an average value of the measurement location 10 to evaluate the oxygen-resistant diffusion layer forming property. It can be judged that the smaller the value of the obtained Vickers hardness Hv, the better the resistance to oxygen diffusion layer formation.
なお図１は、幾つかのチタン合金板について、酸化性雰囲気下、８００℃で１００時間保持した後に切断し、酸化スケールと母材部の界面を試料表面として該表面からの深さとマイクロビッカース硬さの関係を示したグラフである。このグラフにおいて、ベース硬さ（非酸化部の硬さに相当する硬さ）よりも硬くなっている部分が酸素拡散層の厚さに相当し、該厚さの序列は、最表面から１０μｍの深さ位置におけるマイクロビッカース硬さと比較することで対比でき、該ビッカース硬さ（Ｈｖ）の値が大きいものほど酸素拡散層は深いと判断できる。 FIG. 1 shows that some titanium alloy plates were cut after being held at 800 ° C. for 100 hours in an oxidizing atmosphere, and the depth from the surface and the micro Vickers hardness were measured using the interface between the oxide scale and the base material as the sample surface. It is the graph which showed the relationship. In this graph, the portion harder than the base hardness (hardness corresponding to the hardness of the non-oxidized portion) corresponds to the thickness of the oxygen diffusion layer, and the order of the thickness is 10 μm from the outermost surface. It can be compared by comparing with the micro Vickers hardness at the depth position, and it can be judged that the oxygen diffusion layer is deeper as the value of the Vickers hardness (Hv) is larger.
［耐結晶粒成長性］
厚さ約１ｍｍ、長さ１００ｍｍ、幅１０ｍｍの供試チタン合金板を、内部を空気組成に保った加熱炉に装入し、８００℃で１００時間保持した後、該供試板を中央部で切断してから該切断面を倍率１００倍の顕微鏡で写真撮影し、その写真を画像解析することによって結晶粒径を測定し、１０箇所測定の平均値として平均結晶粒径を求める。
[Grain growth resistance]
A test titanium alloy plate having a thickness of about 1 mm, a length of 100 mm, and a width of 10 mm was placed in a heating furnace maintained at an air composition inside and maintained at 800 ° C. for 100 hours. After cutting, the cut surface is photographed with a microscope having a magnification of 100 times, the crystal grain size is measured by image analysis of the photograph, and the average crystal grain size is obtained as an average value of 10 measurements.
なお図２は、参考までにＪＩＳ２種純チタン板の耐高温酸化性試験前後の断面顕微鏡写真を示したもので、左側の写真は試験前（加熱前）のもの、中央は８００℃で１０時間加熱した後のもの、右側の写真は８００℃で１００時間加熱した後のものを夫々示している。この写真からも、試験前の平均結晶粒径に対し加熱試験後は結晶粒径がかなり生長していることが分かる。なお加熱時間が１０時間から１００時間に増えると肉厚はかなり薄くなっているが、該肉厚減量が前述したスケールロスに相当する。 In addition, FIG. 2 shows the cross-sectional micrograph before and after the high temperature oxidation resistance test of the JIS class 2 pure titanium plate for reference. The left photo is before the test (before heating), and the center is 800 ° C. for 10 hours. The one after heating and the photograph on the right side show the one after heating at 800 ° C. for 100 hours, respectively. Also from this photograph, it can be seen that the crystal grain size grew considerably after the heating test with respect to the average crystal grain size before the test. When the heating time is increased from 10 hours to 100 hours, the wall thickness is considerably reduced, but the thickness reduction corresponds to the scale loss described above.
［耐脆化性］
厚さ約１ｍｍの供試チタン合金板から図３に示す寸法形状の試験片を切り出し、各試験片を、内部を空気組成に保った加熱炉に装入し、８００℃で１００時間保持した後、島津製作所製の引張り試験機「オートグラフＡＧ−Ｄ精密万能試験機」を用いて引張り試験を行なう。得られる常温伸び（ｌ1）と、未酸化状態での常温伸び（ｌ0）から、［（ｌ1／ｌ0）×１００（％）］により１０回測定の平均値として算出する。
[Ebrittle resistance]
After cutting out a test piece having a size and shape shown in FIG. 3 from a test titanium alloy plate having a thickness of about 1 mm, each test piece was placed in a heating furnace maintained at an air composition inside and held at 800 ° C. for 100 hours. The tensile test is performed using a tensile tester “Autograph AG-D Precision Universal Tester” manufactured by Shimadzu Corporation. From the room temperature elongation (l 1 ) obtained and the room temperature elongation (l 0 ) in an unoxidized state, the average value of 10 measurements is calculated by [(l 1 / l 0 ) × 100 (%)].
ところで、従来材として使用されている純チタンは耐食性に優れたものであるが、耐高温酸化性を高めるためＡｌやＳｉなどの合金元素を添加すると耐食性は低下するので、腐食の問題も顕在化してくる可能性がある。そこで本発明では、従来のマフラー材では評価されていなかった耐食性も評価項目に加えた。 By the way, pure titanium used as a conventional material has excellent corrosion resistance. However, if alloying elements such as Al and Si are added to improve high-temperature oxidation resistance, the corrosion resistance decreases, and the problem of corrosion becomes obvious. There is a possibility of coming. Therefore, in the present invention, corrosion resistance that has not been evaluated with conventional muffler materials is also added to the evaluation items.
すなわち寒冷地の道路では、路面凍結防止のため塩（塩化ナトリウムや塩化カルシウムなど）の散布が行なわれるが、該路面を走行する自動車や自動二輪のマフラー表面にはこれらの塩が付着する。この塩は水との共存状態下にマフラーの熱で加熱されるとすきま腐食を起こし、穴空き欠陥に発展する可能性がある。そこで、こうした問題にも対処すべく、下記２つの試験法によって耐食性を評価した。 That is, salt (such as sodium chloride and calcium chloride) is sprayed on roads in cold regions to prevent road surface freezing, but these salts adhere to the surfaces of automobiles and motorcycle mufflers traveling on the road surface. When this salt is heated with the heat of a muffler in the presence of water, it may cause crevice corrosion and develop into a hole defect. Therefore, in order to deal with such problems, the corrosion resistance was evaluated by the following two test methods.
［全面腐食試験］
マフラー内の腐食環境を模擬した促進試験として、供試チタン合金板を１％Ｈ2ＳＯ4水溶液の沸騰液に４８時間浸漬した後、供試板の重量を測定する。そして、腐食試験前の供試板の重量から重量減を求め、これを１０個のサンプルについて測定して平均し、この値と試験前の試料の表面積から１年間の腐蝕減量（ｍｍ／年）に換算して求める。
[Full corrosion test]
As an accelerated test simulating the corrosive environment in the muffler, the test titanium alloy plate is immersed in a boiling solution of 1% H 2 SO 4 aqueous solution for 48 hours, and then the weight of the test plate is measured. Then, the weight loss is obtained from the weight of the test plate before the corrosion test, and this is measured for 10 samples and averaged. From this value and the surface area of the sample before the test, the corrosion loss for one year (mm / year). Calculate by converting to
［すきま腐食試験］
塩と水の共存によるすきま腐食環境を模擬した促進試験として、供試チタン合金板を１０％ＮａＣｌ水溶液の沸騰液に２４０時間浸漬し、すきま腐食の発生確率を求める。なお試験は、マルチクレビスによりすきま部を３２箇所作成し、このうち何箇所のすきま部で腐食が生じたかどうかによって発生確率を算出する（試験法の詳細は特許第2871867号参照）。
[Crevice corrosion test]
As an accelerated test simulating the crevice corrosion environment due to the coexistence of salt and water, the test titanium alloy plate is immersed in a boiling solution of 10% NaCl aqueous solution for 240 hours to determine the probability of crevice corrosion. In the test, 32 gaps were created by multi-clevis, and the probability of occurrence was calculated depending on how many of these gaps were corroded (see Japanese Patent No. 2871867 for details of the test method).
また、チタン合金を従来の純チタンに代わるマフラー素材として実用化する上で、強度と加工性が重要な要求特性になることは変わりがないので、これらの物性については、常法に従って引張り特性（引張り強さ、伸び）はＪＩＳ Ｈ４６００，ＪＩＳ Ｚ２２０１,２２４１により、また成形加工性はエリクセン試験（ＪＩＳ Ｚ２２４７）によって評価した。 In addition, the strength and workability will remain important characteristics in putting titanium alloys into practical use as a muffler material to replace conventional pure titanium. (Tensile strength, elongation) were evaluated according to JIS H4600, JIS Z2201, 2241, and molding processability was evaluated according to an Erichsen test (JIS Z2247).
本発明者らは上記試験法を採用し、まずチタンへのＡｌとＳｉの好適含有量とその効果について検討した。 The inventors of the present invention adopted the above test method, and firstly examined the preferred contents of Al and Si in titanium and the effects thereof.
Ａｌは、周知の通りチタン材に対し耐熱性を高める作用を有する合金元素であり、Ａｌ含有量を多くするにつれて耐熱性や耐高温酸化性（耐スケールロス性、耐酸素拡散層形成性、耐結晶粒成長性）は改善される。しかしその反面、Ａｌ含有量を多くするにつれて延性が大幅に低下してくると共に耐食性も低下してくる。こうした利害得失を考慮し、マフラー素材などとして必要な最低限の成形加工性と耐食性を確保しつつ、高レベルの耐熱性や高温耐酸化性を確保するには、Ａｌ含量を少なくとも０．３０％以上含有させねばならず、好ましくは０．４０％以上含有させるのがよく、上限は多くとも１．５０％以下、好ましくは１．０％以下、更に好ましくは０．８％以下に抑えることが望ましい。 As is well known, Al is an alloying element that has an effect of increasing heat resistance to a titanium material. As the Al content is increased, heat resistance and high-temperature oxidation resistance (scale loss resistance, oxygen diffusion layer formation resistance, resistance resistance) (Grain growth) is improved. On the other hand, as the Al content is increased, the ductility is significantly reduced and the corrosion resistance is also lowered. Considering these advantages and disadvantages, to ensure the high level of heat resistance and high-temperature oxidation resistance while ensuring the minimum formability and corrosion resistance required for muffler materials, etc., the Al content should be at least 0.30%. The upper limit should be 1.50% or less, preferably 1.0% or less, and more preferably 0.8% or less. desirable.
次に、Ｓｉがチタン合金の結晶粒の成長抑制に優れた効果を発揮し、疲労特性の向上に寄与することは既に確認されており、こうした作用は本発明においても有効に発揮される。しかし本発明において特筆すべきＳｉの添加効果は、Ａｌとの複合添加によって高温強度の向上に寄与するほか、耐食性の低下を最小限に抑えつつ耐高温酸化性、特に耐スケールロス性や耐酸素拡散層形成性を高め、更には、結晶粒の成長抑制によって疲労特性や脆性の向上に寄与する点である。 Next, it has already been confirmed that Si exhibits an excellent effect in suppressing the growth of crystal grains of the titanium alloy and contributes to an improvement in fatigue characteristics, and such an effect is also effectively exhibited in the present invention. However, the addition effect of Si, which is notable in the present invention, contributes to the improvement of the high-temperature strength by the combined addition with Al, and also provides high-temperature oxidation resistance, particularly scale loss resistance and oxygen resistance, while minimizing the decrease in corrosion resistance. It is a point which contributes to improvement of fatigue characteristics and brittleness by improving diffusion layer formation and further suppressing growth of crystal grains.
こうしたＳｉの効果を有効に発揮させるには、Ｓｉを０．１０％以上含有させる必要があり、好ましくは０．２０％以上、更に好ましくは０．３０％以上含有させるのがよい。しかしＳｉ含量が多過ぎると、耐食性に及ぼす悪影響が軽視できなくなると共に成形性も劣化するので、多くとも１．０％以下に抑えるべきであり、好ましくは０．８％以下、更に好ましくは０．７％以下に抑えることが望ましい。 In order to effectively exhibit such effects of Si, it is necessary to contain 0.10% or more of Si, preferably 0.20% or more, and more preferably 0.30% or more. However, if the Si content is too high, the adverse effect on the corrosion resistance cannot be neglected and the moldability also deteriorates. Therefore, it should be suppressed to 1.0% or less at most, preferably 0.8% or less, more preferably 0.8. It is desirable to keep it below 7%.
上記の様にＳｉは、Ａｌ添加による耐食性の低下を最小限に抑えつつＡｌにほぼ匹敵する耐高温特性の向上効果を発揮するもので、こうした言わばＡｌ代替元素としての効果をより効果的に発揮させるには、Ｓｉ含量をＡｌ含量に対する質量比率で１／３以上にすることが望ましく、より好ましくは１／２以上、更に好ましくは４／５以上にするのがよい。但し該比率が大きくなり過ぎると、Ａｌに期待される効果、特に耐高温特性向上効果が有効に発揮され難くなるので、好ましくは２．０以下、より好ましくは１．５以下に抑えるべきである。 As mentioned above, Si exhibits the effect of improving high temperature resistance that is almost comparable to Al while minimizing the deterioration of corrosion resistance due to the addition of Al. In other words, it effectively demonstrates the effect as an Al substitute element. For this purpose, the Si content is desirably 1/3 or more by mass ratio with respect to the Al content, more preferably 1/2 or more, still more preferably 4/5 or more. However, if the ratio is too large, the effect expected of Al, particularly the high temperature resistance improvement effect is hardly exhibited effectively, so it should preferably be suppressed to 2.0 or less, more preferably 1.5 or less. .
上記の様に本発明のチタン合金は、マフラー用素材等として求められる成形加工性を確保しつつ特に優れた耐高温酸化性と耐食性を高めるため適量のＡｌとＳｉを含有させるところに特徴を有しており、その最も単純で原料コストや量産性も加味した好ましい合金組成はＴｉ−（０．３０〜１．５０％）Ａｌ−（０．１０〜１．０％）Ｓｉからなる３元系のチタン合金である。しかし、更に適量のＮｂを含有させると、耐食性に殆んど悪影響を及ぼすことなく耐スケールロス性や耐酸素拡散層形成性を一段と高めることができるので好ましい。こうしたＮｂの効果は、質量基準で０．１０％以上、より好ましくは０．１５％以上含有させることによって有効に発揮される。しかしＮｂ含量が多過ぎると、耐食性や成形加工性に悪影響が現われてくる他、Ｎｂは比較的高価な元素で多量添加は経済的にも不利であるので、０．５％以下、より好ましくは０．３％以下に抑えるのがよい。 As described above, the titanium alloy of the present invention is characterized in that it contains appropriate amounts of Al and Si in order to enhance the particularly high-temperature oxidation resistance and corrosion resistance while ensuring the moldability required as a muffler material. The preferred alloy composition that is the simplest and takes into consideration raw material costs and mass productivity is a ternary system composed of Ti- (0.30 to 1.50%) Al- (0.10 to 1.0%) Si. This is a titanium alloy. However, it is preferable to further contain an appropriate amount of Nb, since the scale loss resistance and the oxygen diffusion layer forming property can be further enhanced without almost adversely affecting the corrosion resistance. Such an effect of Nb is effectively exhibited by containing 0.10% or more, more preferably 0.15% or more on a mass basis. However, if the Nb content is too high, the corrosion resistance and molding processability will be adversely affected. In addition, Nb is a relatively expensive element, and it is economically disadvantageous, so 0.5% or less, more preferably It is better to keep it below 0.3%.
上記以外の添加許容元素としては、Ｔａ，Ｗ，Ｍｏ，Ｃｒ，Ｚｒ，Ｈｆ等が挙げられ、これらの元素は夫々単独で、あるいは２種以上を任意の組合せで併用することによって、耐スケールロス性や耐酸素拡散層形成性の向上に寄与する他、Ｓｉほどではないが結晶粒成長抑制作用も有しており、疲労特性や脆性を高める作用も有している。こうした効果は、これら各元素の少なくとも１種を総和で０．１％程度以上含有させることによって有効に発揮される。しかしこれら合金元素の含有量が多過ぎると、成形加工性に悪影響が現われてくるので、前記Ａｌ，Ｓｉ，Ｎｂの含有量を含めて総含有量で２．５％、より好ましくは２．０％を超えないように含有量を調整すべきである。 Examples of elements other than the above that can be added include Ta, W, Mo, Cr, Zr, and Hf. These elements can be used alone or in combination of two or more in any combination, thereby preventing loss of scale loss. In addition to contributing to the improvement of the property and the oxygen-resistant diffusion layer forming property, it also has an effect of suppressing crystal grain growth, which is not as high as that of Si, and also has an effect of improving fatigue characteristics and brittleness. Such an effect is effectively exhibited by containing at least one of these elements in a total amount of about 0.1% or more. However, if the content of these alloy elements is too large, there will be an adverse effect on the formability, so the total content including the content of Al, Si, Nb is 2.5%, more preferably 2.0%. The content should be adjusted not to exceed%.
本発明に係るチタン合金の残部成分は実質的にチタンである。ここで「実質的に」とは、原料チタンの種類（チタン鉱石やスクラップ、精製法など）に由来する微量元素の混入を許容するという意味であり、微量元素としては、例えばＯ（酸素），Ｆｅ，Ｈ（水素），Ｃ（炭素），Ｎ（窒素）などが挙げられる。これらの元素は、前述した本発明の特性に悪影響を及ぼさない量である限り具体的な上限値は元素の種類によって変わってくるが、本発明では一応の許容含有量を、それぞれＯは０．１５％以下（より好ましくは０．１２％以下），Ｆｅは０．２０％以下（より好ましくは０．１５％以下），Ｈは０．０３％以下（より好ましくは０．０１５％以下），Ｃは０．０８％以下（より好ましくは０．０３％以下），Ｎは０．０５％以下（より好ましくは０．０３％以下）と定めている。 The balance component of the titanium alloy according to the present invention is substantially titanium. Here, “substantially” means to allow mixing of trace elements derived from the type of raw material titanium (titanium ore, scrap, refining method, etc.). As trace elements, for example, O (oxygen), Fe, H (hydrogen), C (carbon), N (nitrogen) and the like can be mentioned. As long as these elements are in amounts that do not adversely affect the above-described characteristics of the present invention, the specific upper limit varies depending on the type of the elements. 15% or less (more preferably 0.12% or less), Fe is 0.20% or less (more preferably 0.15% or less), H is 0.03% or less (more preferably 0.015% or less), C is defined as 0.08% or less (more preferably 0.03% or less), and N is defined as 0.05% or less (more preferably 0.03% or less).
上記以外に混入が予測される元素としてＮｉ，Ｃｌ，Ｍｇ，Ｍｎ，Ｎａ，Ｃｕ，Ｖ，Ｓｎ，Ｐｂ，Ｒｕ，Ｃｏ，Ｓなどが挙げられ、これらの元素も、混入経路の如何を問わず、前述した特性（耐熱性、耐食性、成形加工性など）に実質的な悪影響を及ぼさない範囲で微量の混入が許容されるが、それぞれ概ね数百ｐｐｍ程度以下に抑えるのがよい。 In addition to the above, Ni, Cl, Mg, Mn, Na, Cu, V, Sn, Pb, Ru, Co, S and the like can be cited as elements that are expected to be mixed, and these elements may be used regardless of the mixing route. Although a slight amount of mixing is allowed as long as it does not have a substantial adverse effect on the above-described characteristics (heat resistance, corrosion resistance, molding processability, etc.), it is preferable to suppress the amount to about several hundred ppm or less.
尚本発明のチタン合金は、前述の如く従来の純チタンに匹敵する冷間圧延性と成形加工性を有しているので、該合金を用いたマフラー用素材やマフラーの製法は純チタンに準じた方法を採用すればよく、例えば、所定の合金組成となる様に原料成分を調整して溶製しインゴットを作った後、常法に従って鍛造および熱間圧延の後焼鈍してから表面を脱スケールする。次いで所定厚さまで冷間圧延してから焼鈍し、得られるコイルをスリットしてフープを作成し、これを造管機で管状に連続成形しＴＩＧ溶接することによって素管を製造する。そしてこの素管を寸法・形状を整えた純チタンやチタン合金（好ましくは本発明のチタン合金）製の端板などと組み付けることでマフラー状に加工すればよい。 Since the titanium alloy of the present invention has cold rollability and formability comparable to conventional pure titanium as described above, the muffler material using the alloy and the manufacturing method of the muffler conform to pure titanium. For example, after adjusting the raw material components so as to have a predetermined alloy composition and making an ingot by melting, after forging and hot rolling according to conventional methods, the surface is removed. Scale. Next, cold rolling to a predetermined thickness and annealing are performed, and the obtained coil is slit to form a hoop, which is continuously formed into a tubular shape by a pipe making machine, and TIG welding is performed to manufacture a raw pipe. Then, the element tube may be processed into a muffler by assembling with an end plate made of pure titanium or a titanium alloy (preferably the titanium alloy of the present invention) whose dimensions and shape are adjusted.
この間の熱延条件や冷延条件、焼鈍条件、シーム溶接条件などは、用いるチタン合金の成分組成などに応じてその都度適正に調整すればよい。 The hot rolling conditions, cold rolling conditions, annealing conditions, seam welding conditions, and the like during this period may be appropriately adjusted each time according to the composition of the titanium alloy used.
上記の様に本発明では、チタン中に配合するＡｌおよびＳｉ含有量を特定し、あるいは更には適量のＮｂを含有せしめ、更には、Ｔａ，Ｗ，Ｍｏ，Ｃｒ，Ｚｒ，Ｈｆから選ばれる少なくとも１種を含有させることによって、優れた成形加工性を確保しつつ耐食性、耐高温酸化性（耐スケールロス性、酸素拡散層形成性、結晶粒成長抑制性）、耐熱性などを高めたところに特徴を有している。しかし、本発明に係るチタン合金製品の表面に耐高温酸化特性や耐食性の更に優れた表面処理を施しておくことは、マフラー用素材等として耐久寿命を更に高める上で有効である。 As described above, in the present invention, the content of Al and Si to be blended in titanium is specified, or an appropriate amount of Nb is further contained, and at least selected from Ta, W, Mo, Cr, Zr, and Hf. By including one type, it has improved corrosion resistance, high-temperature oxidation resistance (scale loss resistance, oxygen diffusion layer formation, crystal grain growth suppression), heat resistance, etc. while ensuring excellent moldability. It has characteristics. However, it is effective for the surface of the titanium alloy product according to the present invention to further improve the durability life as a muffler material or the like by applying a surface treatment with further excellent high temperature oxidation resistance and corrosion resistance.
その様な保護皮膜として好ましいのは、溶融ＡｌめっきやＡｌ合金めっきである。溶融ＡｌまたはＡｌ合金めっきとして特に好ましいのは、ＡｌまたはＡｌとＳｉの総含有量が９０質量以上である耐熱性のＡｌ合金めっきであり、その好ましい厚さは１μｍ以上、より好ましくは５μｍ以上である。なお、該Ａｌ系溶融めっきと基材チタン合金との界面には、例えばＡｌ3Ｔｉの如きＡｌ−Ｔｉ系金属間化合物を介在させ、基材とめっき層との密着性を高めることが好ましい。 Preferable as such a protective film is hot-dip Al plating or Al alloy plating. Particularly preferable as the molten Al or Al alloy plating is a heat-resistant Al alloy plating in which the total content of Al or Al and Si is 90 mass or more, and the preferred thickness is 1 μm or more, more preferably 5 μm or more. is there. In addition, it is preferable to interpose an Al—Ti intermetallic compound such as Al 3 Ti at the interface between the Al-based hot dipping and the base material titanium alloy to enhance the adhesion between the base material and the plating layer.
次に、本発明に係るチタン合金におけるＡｌとＳｉの含有率が引張り特性とエリクセン値（成形加工性）、耐食性および耐酸化性に及ぼす影響を、後述する実施例を含めて整理した図面によって説明する。 Next, the influence of the Al and Si contents in the titanium alloy according to the present invention on tensile properties, Erichsen values (formability), corrosion resistance, and oxidation resistance will be described with reference to the drawings including examples described later. To do.
図４は、チタン合金中に含まれるＡｌとＳｉの量が引張り特性とエリクセン値に与える影響を示したグラフであり、図中、〇印で示される測定点に示した四角で囲った数値は伸び率（％）、（ ）で囲った数値はエリクセン値、単に数値で示したのは引張り強さ（ＭＰａ）を示している。尚、Ａｌ：０％，Ｓｉ：０％の位置はＪＩＳ２種純チタンを意味する。 FIG. 4 is a graph showing the effect of the amount of Al and Si contained in the titanium alloy on the tensile properties and the Erichsen value. In the figure, the numerical values enclosed by the squares shown at the measurement points indicated by ◯ are Elongation rate (%), numerical values enclosed in parentheses () indicate Erichsen values, and numerical values simply indicate tensile strength (MPa). The positions of Al: 0% and Si: 0% mean JIS type 2 pure titanium.
また、図面右側の縮小図に示した符号Ａ，Ｂ，Ｃ，Ｄ，ＣＤ，ＣＣ，ＤＤは、本発明で定めるクレーム要件との関係を領域として示した説明図で、右上がりの直線は「Ｓｉ＝1/3×Ａｌ」、領域ＡとＢは、本発明で定める「Ａｌ＝０．３０〜１．５０％」と「Ｓｉ＝０．１０〜１．０％」を同時に満たす領域を示しており、領域Ｃは、ＡｌとＳｉの一方の含有率は適切であるが他方の含有率が不足する比較材、領域Ｄは、ＡｌとＳｉの一方の含有率は適切であるが他方の含有率が多過ぎる比較材、領域ＣＤは、ＡｌとＳｉの一方の含有率が不足すると共に他方の含有率は多過ぎる比較材、領域ＣＣは、ＡｌとＳｉの両方が規定範囲に満たない比較材、領域ＤＤは、ＡｌとＳｉの両方が規定範囲を超える比較材の領域である。 Further, reference signs A, B, C, D, CD, CC, and DD shown in the reduced view on the right side of the drawing are explanatory diagrams showing the relationship with the claim requirements defined in the present invention as an area. “Si = 1/3 × Al” and regions A and B indicate regions that simultaneously satisfy “Al = 0.30-1.50%” and “Si = 0.10-1.0%” defined in the present invention. The region C is a comparative material in which the content of one of Al and Si is appropriate but the content of the other is insufficient, and the region D is suitable for the content of one of Al and Si but contains the other Comparative material having a too high ratio, region CD is a comparative material in which one of Al and Si is insufficient and the other content is too large, and region CC is a comparative material in which both Al and Si are less than the specified range. The region DD is a region of the comparative material in which both Al and Si exceed the specified range.
この図の各点に示した引張り強さ、伸び率、エリクセン値から総合的に解析すると、下記の傾向を読取ることができる。 The following tendencies can be read by comprehensively analyzing from the tensile strength, elongation rate, and Erichsen value shown at each point in the figure.
即ち領域ＣＣは、Ａｌ，Ｓｉの含有量がいずれも規定範囲に満たないためエリクセン値が高く、成形加工性については全く問題のない領域である。また領域Ｃは、Ａｌ，Ｓｉの一方の含有率は適切であるが他方が不足するもので、相対的にエリクセン値が高く成形性は良好である。領域Ｄは、Ａｌ，Ｓｉの一方の含有率は適切であるが他方が多過ぎるもので、相対的に高強度でエリクセン値が高く成形加工性が悪い。領域ＣＤは、Ａｌ，Ｓｉの一方の含有率が過剰で他方の含有率が不足する領域であり、過剰成分に起因するエリクセン値の低下が顕著で成形加工性に欠ける。領域ＤＤは、Ａｌ，Ｓｉの含有率がいずれも多過ぎる領域であり、強度が高過ぎてエリクセン値が低く、成形加工性が劣悪である。 That is, the region CC is a region where the Erichsen value is high because the contents of Al and Si are less than the specified range, and there is no problem with the molding processability. In the region C, the content of one of Al and Si is appropriate but the other is insufficient, and the Erichsen value is relatively high and the moldability is good. In the region D, the content of one of Al and Si is appropriate, but the other is too much, and the strength is relatively high, the Erichsen value is high, and the moldability is poor. The region CD is a region in which one of Al and Si is excessive and the other is insufficient, and the decrease in the Erichsen value due to the excessive component is remarkable and the molding processability is lacking. The region DD is a region where both Al and Si contents are too high, the strength is too high, the Erichsen value is low, and the molding processability is poor.
これらに対し領域Ａ，Ｂは本発明の規定要件を満たす領域であり、ＪＩＳ２種純チタン（Ａｌ，Ｓｉが共にゼロ％）に比べると引張り強さがやや高く、伸び率とエリクセン値はやや低い値となっているが、この程度であれば実用上は純チタン並みの成形加工性を有するものと評価できる。 On the other hand, regions A and B are regions that satisfy the requirements of the present invention. The tensile strength is slightly higher than that of JIS type 2 pure titanium (both Al and Si are 0%), and the elongation rate and Erichsen value are slightly lower. Although it is a value, if it is this level, it can be evaluated practically as having a formability comparable to that of pure titanium.
図５は、チタン合金中に含まれるＡｌとＳｉの量が耐食性に与える影響を整理して示したグラフであり、図中、〇印で示される測定点に示した四角で囲った数値は全面腐食速度（ｍｍ／年）、（ ）で囲った数値はすきま腐食発生確率（％）を示している。なおこれらの試験条件は前述した通りであり、いずれも実使用条件よりも厳しい条件での試験であって、実際の使用条件で図示したレベルの腐食が起こるわけではない。 FIG. 5 is a graph summarizing the effects of the amount of Al and Si contained in the titanium alloy on the corrosion resistance. In the figure, the numerical values enclosed by the squares indicated by the measurement points indicated by the circles are the entire surface. Corrosion rate (mm / year), the numerical value enclosed in parentheses indicates the crevice corrosion occurrence probability (%). Note that these test conditions are as described above, and all of them are tests that are severer than the actual use conditions, and the level of corrosion shown in the actual use conditions does not occur.
また、図面右側の縮小図に示した符号Ａ，Ｂ，Ｃ，Ｄ、ＣＤ，ＣＣ，ＤＤは、前記図４に示した縮小図で説明したのと同じである。 The symbols A, B, C, D, CD, CC, and DD shown in the reduced diagram on the right side of the drawing are the same as those described in the reduced diagram shown in FIG.
この図の各点に示した全面腐食速度とすきま腐食発生確率から総合的に解析すると、下記の傾向を読取ることができる。 The following trends can be read by comprehensively analyzing from the overall corrosion rate and the crevice corrosion occurrence probability shown in each point of this figure.
領域ＣＣは、Ａｌ，Ｓｉの含有量がいずれも規定範囲に満たない領域であり、全面腐食速度およびすきま腐食発生確率ともにＪＩＳ２種純チタン材とほぼ同レベルの値が得られる。また領域Ｃは、Ａｌ，Ｓｉのうち１方の含有率は適切であるが他方の含有率が不足するもので、全面腐食速度およびすきま腐食発生確率ともに、他の領域に比べて耐食性の低下度合いは少ない。また領域Ｄおよび領域ＤＤは、Ａｌ，Ｓｉの１方もしくは双方が多過ぎる領域であり、全面腐食速度およびすきま腐食発生確率共に、他の領域に比べて高い値を示す。領域ＣＤは、Ａｌ，Ｓｉのいずれか一方の含有率は不足するが他方の含有率が多過ぎる領域であり、過剰合金元素の影響が強く現われて、全面腐食速度およびすきま腐食発生確率がともに不良である。 The region CC is a region where the contents of Al and Si are both less than the specified range, and the surface corrosion rate and the crevice corrosion occurrence probability are almost the same level as that of the JIS class 2 pure titanium material. In region C, the content of one of Al and Si is appropriate, but the content of the other is insufficient, and both the overall corrosion rate and the crevice corrosion occurrence probability are lower than the other regions. There are few. Region D and region DD are regions in which one or both of Al and Si are too much, and the overall corrosion rate and the crevice corrosion occurrence probability are higher than those in the other regions. Region CD is a region where the content of either Al or Si is insufficient, but the content of the other is too large, and the influence of excess alloy elements appears strongly, resulting in poor overall corrosion rate and crevice corrosion occurrence probability. It is.
これらに対し領域Ａ，Ｂは、本発明の規定要件を満たす好適領域であり、領域ＣＣやＣに比べると耐食性は劣るものの、他の領域に比べると劣化度合いは少なく抑えられている。 On the other hand, the areas A and B are suitable areas that satisfy the prescribed requirements of the present invention. Although the corrosion resistance is inferior to the areas CC and C, the degree of deterioration is suppressed to a small extent compared to other areas.
またこの図より、チタンにＡｌとＳｉをそれぞれ単独で添加した場合、Ａｌの方が耐食性の劣化度合いは大きく、また同じ総含有量で比較すると、Ａｌを単独で添加する場合よりもＡｌとＳｉを複合添加した場合の方が、全面腐食速度およびすきま腐食発生確率共に増加傾向は明らかに低下している。 Also, from this figure, when Al and Si are added individually to titanium, the degree of deterioration of corrosion resistance is greater with Al, and when compared with the same total content, Al and Si are compared with the case where Al is added alone. In the case of compounding, the increasing tendency of both the overall corrosion rate and the crevice corrosion occurrence rate is clearly reduced.
ちなみに図６，７は、Ａｌを単独で添加した場合と、ＡｌとＳｉを複合添加した場合について、総添加合金元素量が全面腐食速度とすきま腐食発生確率に与える影響を整理して示したグラフである。これらの図からも明らかな様に、Ａｌ単独添加では、全面腐食速度、すきま腐食発生確率ともにほぼ直線的に高まっているのに対し、Ａｌの一部をＳｉに置換し、且つその置換量を増大するにつれて、腐食速度、腐食発生確率ともに上昇傾向は明らかに抑えられる傾向を確認できる。これらの傾向から、Ａｌの一部をＳｉに置換することで耐食性の劣化を最小限に抑え得ることが確認できる。 6 and 7 are graphs showing the effects of the total amount of alloying elements on the overall corrosion rate and crevice corrosion probability when Al is added alone and when Al and Si are added together. It is. As is clear from these figures, when Al alone is added, the overall corrosion rate and the crevice corrosion occurrence probability increase almost linearly, whereas a part of Al is replaced by Si and the amount of substitution is changed. As it increases, it can be confirmed that the rising tendency of both the corrosion rate and the corrosion occurrence probability is clearly suppressed. From these tendencies, it can be confirmed that deterioration of corrosion resistance can be minimized by substituting a part of Al with Si.
次に図８は、チタン合金中に含まれるＡｌとＳｉの量が耐高温酸化性（耐スケールロス性、耐酸素拡散層形成性、耐結晶粒成長性）に与える影響を整理して示したグラフであり、図中、各測定点に示した〇印、斜線〇印および●印は、前掲の耐スケールロス性試験で得られた板厚減少率（Ｘ）が１％未満、１％以上５％未満、５％以上のものを表わしている。また各〇印の部分に数字で示したのは耐酸素拡散層形成性を示すもので、８００℃×１００時間酸化処理した後の最表面から１０μｍの深さにおける断面ビッカース硬さの値、四角で囲った数値は耐結晶粒成長性を示すもので、同じく８００℃×１００時間酸化処理後の平均結晶粒径の値、（ ）で囲った数値は耐脆化性を示すもので、同じく８００℃×１００時間酸化処理後の常温伸び率の低下量（％）を表わしている。 Next, FIG. 8 summarizes the effects of the amounts of Al and Si contained in the titanium alloy on high-temperature oxidation resistance (scale loss resistance, oxygen diffusion layer resistance, crystal grain growth resistance). It is a graph. In the figure, the ○ mark, the hatched O mark, and the ● mark shown at each measurement point indicate that the plate thickness reduction rate (X) obtained in the scale loss resistance test described above is less than 1%, 1% or more. It represents less than 5% and 5% or more. In addition, the numbers shown in the circles indicate the oxygen-resistant diffusion layer forming property, the value of the cross-section Vickers hardness at a depth of 10 μm from the outermost surface after oxidation treatment at 800 ° C. for 100 hours, square The numerical value enclosed in brackets indicates resistance to crystal grain growth, the value of the average crystal grain size after the oxidation treatment at 800 ° C. for 100 hours, and the numerical value surrounded by parentheses () indicates resistance to embrittlement. It represents the decrease (%) in the normal temperature elongation after the oxidation treatment at 100 ° C. for 100 hours.
また、図面右側の縮小図に示した符号Ａ，Ｂ，Ｃ，Ｄ、ＣＤ，ＣＣ，ＤＤは、前記図４に示した縮小図で説明したのと同じである。 The symbols A, B, C, D, CD, CC, and DD shown in the reduced diagram on the right side of the drawing are the same as those described in the reduced diagram shown in FIG.
この図に示した耐スケールロス性、耐酸素拡散層形成性、耐結晶粒成長性、耐脆化性から総合的に解析すると、下記の傾向を読取ることができる。 When comprehensively analyzed from the scale loss resistance, oxygen diffusion layer formation resistance, crystal grain growth resistance, and embrittlement resistance shown in this figure, the following tendencies can be read.
領域ＤＤは、耐高温酸化性の向上に有効なＡｌ，Ｓｉの含有量がいずれも多過ぎる領域であり、上記４特性の何れも優れた値となる。また領域ＣＣは、逆にＡｌ，Ｓｉの含有量がいずれも不足するため、上記４特性の何れの値も低く、満足な耐高温酸化性が得られない。また領域Ｃは、Ａｌ，Ｓｉの一方の含有率は適切であるが他方の含有率が不足するため４特性の何れも相対的に低く、満足な耐高温酸化性が得られない。領域Ｄは、Ａｌ，Ｓｉの一方の含有率は適切であるが他方の含有率が多過ぎる領域で、耐高温酸化性は良好である。領域ＣＤは、Ａｌ，Ｓｉの一方の含有率が不足すると共に他方の含有率は多過ぎる領域であり、過剰分のＡｌまたはＳｉの効果でそれなりの耐高温酸化性を得ることができる。 The region DD is a region where there is too much content of Al and Si effective for improving high-temperature oxidation resistance, and all of the above four characteristics are excellent values. On the other hand, in the region CC, since the contents of Al and Si are insufficient, any of the above four characteristics is low, and satisfactory high-temperature oxidation resistance cannot be obtained. In the region C, the content of one of Al and Si is appropriate, but the content of the other is insufficient. Therefore, all of the four characteristics are relatively low, and satisfactory high-temperature oxidation resistance cannot be obtained. The region D is a region in which one of Al and Si is appropriate, but the other is too much, and the high-temperature oxidation resistance is good. The region CD is a region in which one of Al and Si is insufficient and the other is too much, and an appropriate amount of high temperature oxidation resistance can be obtained by the effect of excess Al or Si.
これらに対し領域Ａ，Ｂは適量のＡｌとＳｉを含む実施例領域であり、領域Ｄほどではないが領域ＣＣやＣに比べると何れも優れた値を示している。これらの中でも領域Ａは、Ｓｉ含量がＡｌ含量の１／３以上である好適実施例であり、領域Ｂよりも明らかに優れた耐高温酸化特性を示している。 On the other hand, the regions A and B are example regions containing appropriate amounts of Al and Si, and although not as much as the region D, both have superior values compared to the regions CC and C. Among these, the region A is a preferred embodiment in which the Si content is 1/3 or more of the Al content, and shows high temperature oxidation resistance clearly superior to the region B.
上記図４〜８を総合的に観察すると、下記の傾向を確認できる。 The following tendencies can be confirmed by comprehensively observing FIGS.
本発明者らが先に開発した相対的にＡｌ含量を抑えたＴｉ−Ａｌ合金に適量のＳｉを添加し、好ましくはＡｌの一部に置き代えて適量のＳｉを添加することで、公知のチタン合金では実施されたことのない厳しい耐高温酸化性評価試験においても卓越した耐高温酸化性と耐食性を示すチタン合金を得ることができる。しかも、全体としての合金元素の含有量を最小限に抑えることで、実用上、純チタン材と同程度の加工性も保障できる。更に、総添加合金元素量で比較すると、Ａｌを単独で添加する場合よりもＳｉを併用することで耐食性の低下も最小限に抑えることができ、結果的に耐高温酸化性と耐食性を両立しつつ、成形加工性にも優れたチタン合金を得ることが可能となる。 An appropriate amount of Si is added to the Ti-Al alloy with a relatively low Al content developed previously by the present inventors, and preferably an appropriate amount of Si is added instead of a part of Al. Titanium alloys exhibiting excellent high-temperature oxidation resistance and corrosion resistance can be obtained even in rigorous high-temperature oxidation resistance evaluation tests that have never been performed with titanium alloys. In addition, by minimizing the content of the alloy elements as a whole, practically the same workability as that of a pure titanium material can be ensured. Furthermore, when compared with the total amount of alloying elements added, it is possible to minimize the decrease in corrosion resistance by using Si together with the case where Al is added alone, and as a result, both high-temperature oxidation resistance and corrosion resistance are achieved. On the other hand, it is possible to obtain a titanium alloy that is excellent in moldability.
また後述する実施例でも明らかにする如く、更に他の元素として適量のＮｂを添加し、あるいは更にＴａ，Ｗ，Ｍｏ，Ｃｒ，Ｚｒ，Ｈｆの１種以上を適量複合添加することで、耐高温酸化性と耐食性および成形加工性の全てにおいてバランスの取れたチタン合金を得ることが可能となる。 Further, as will be clarified in the examples described later, an appropriate amount of Nb is further added as another element, or an appropriate amount of at least one of Ta, W, Mo, Cr, Zr, and Hf is added in combination. It becomes possible to obtain a titanium alloy balanced in all of oxidation resistance, corrosion resistance and moldability.
以下、実施例を挙げて本発明の構成と作用効果をより具体的に説明するが、本発明はもとより下記実施例によって制限を受ける訳ではなく、前・後記の趣旨に適合し得る範囲で適当に変更して実施することも可能であり、それらはいずれも本発明の技術的範囲に包含される。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and is suitable as long as it can meet the purpose described above and below. It is also possible to carry out by changing to the above, and they are all included in the technical scope of the present invention.
実施例１
原料としてＪＩＳ１種純チタン板と所定の添加元素を使用し、真空ボタン溶解炉によって表１に示す成分組成のチタン合金鋳塊（１００〜２００ｇ）を製造し、これを１０００℃で２時間加熱した後、厚さ６ｍｍまで熱間圧延した。次いで、１０００℃で２０分間加熱した後、引き続いて８４０℃で１時間加熱し、その後、直ちに６ｍｍから厚さ２．５ｍｍまで熱間圧延を行なった。
Example 1
Using a JIS type 1 pure titanium plate and a predetermined additive element as raw materials, a titanium alloy ingot (100 to 200 g) having the composition shown in Table 1 was produced by a vacuum button melting furnace, and this was heated at 1000 ° C. for 2 hours. Then, it hot-rolled to thickness 6mm. Next, after heating at 1000 ° C. for 20 minutes, it was subsequently heated at 840 ° C. for 1 hour, and then immediately hot-rolled from 6 mm to a thickness of 2.5 mm.
得られた熱延板を８００℃で２０分間焼鈍し、空冷した後、表面の酸化スケール除去のため片面０．５ｍｍの平面研削を行い、更に冷間圧延により厚さ約１ｍｍの供試チタン合金板を作製した。更に、最終仕上げとして６５０℃×３時間（均熱時間）の真空焼鈍を行った。 The obtained hot-rolled sheet was annealed at 800 ° C. for 20 minutes, air-cooled, then subjected to surface grinding of 0.5 mm on one side to remove the oxide scale on the surface, and further a test titanium alloy having a thickness of about 1 mm by cold rolling. A plate was made. Further, vacuum annealing at 650 ° C. for 3 hours (soaking time) was performed as the final finish.
得られた各供試板について、引張り特性と加工性を評価するため、常温（２５℃）および高温（６００℃、８００℃）での引張試験（同前）とエリクセン試験（同前）を行った。尚この試験では、引張試験の上限温度を８００℃としているが、本発明のチタン合金の使用温度が８００℃以下に制限されるものでないことは言うまでもない。 In order to evaluate the tensile properties and workability of each test plate obtained, a tensile test (same as above) and an Eriksen test (same as above) at normal temperature (25 ° C) and high temperature (600 ° C, 800 ° C) were conducted. It was. In this test, although the upper limit temperature of the tensile test is 800 ° C., it goes without saying that the use temperature of the titanium alloy of the present invention is not limited to 800 ° C. or less.
また、得られた各供試板について、耐食性を全面腐食試験とすきま腐食試験によって評価すると共に、耐高温酸化性を評価した。なお全面腐食試験は、沸騰した１％Ｈ2ＳＯ4に４８時間浸漬したときの重量変化から腐食速度を算出した。この試験環境はマフラー内の腐食環境を模擬したものである。またすきま腐食試験は、マルチクレビスにより試験片上にすきま部を３２個作製し、沸騰した１０％ＮａＣｌ水溶液に２４０時間浸漬した後で、３２個のすきまのうち何個ですきま腐食が発生したかにより、すきま腐食発生確率を算出した。この腐食環境は、マフラー外の環境を模擬したものである。なお、これらの腐食試験は実使用環境よりも厳しい条件で比較しており、実使用において同レベルの腐食が起こることを意味するものではない。 Each of the obtained test plates was evaluated for corrosion resistance by a general corrosion test and a crevice corrosion test, as well as high temperature oxidation resistance. In the overall corrosion test, the corrosion rate was calculated from the change in weight when immersed in boiling 1% H 2 SO 4 for 48 hours. This test environment simulates the corrosive environment in the muffler. The crevice corrosion test is based on how many crevice corrosion occurred in 32 crevices after making 32 crevice parts on a test piece with multiclevis and immersing in boiling 10% NaCl aqueous solution for 240 hours. The crevice corrosion occurrence probability was calculated. This corrosive environment simulates the environment outside the muffler. In addition, these corrosion tests are compared under conditions that are severer than the actual use environment, and do not mean that the same level of corrosion occurs in actual use.
また耐高温酸化性評価法のうち、耐スケールロス性は８００℃で１００時間酸化させた前後の板厚減少率で評価した。耐酸素拡散層形成性は、前述した如く８００℃で１００時間酸化させた後、最表面から約１０μｍの深さにおけるマイクロビッカース硬さを測定することで評価した。耐結晶粒成長性は、８００℃で１００時間酸化した後の結晶粒径を測定することで評価した。耐脆化性は、［８００℃で１００時間酸化した後の常温伸び／未酸化状態での常温伸び］×１００（％）を算出することで評価した。 In addition, among the high temperature oxidation resistance evaluation methods, the scale loss resistance was evaluated by the plate thickness reduction rate before and after oxidation at 800 ° C. for 100 hours. As described above, the oxygen diffusion layer forming property was evaluated by measuring the micro Vickers hardness at a depth of about 10 μm from the outermost surface after oxidation at 800 ° C. for 100 hours. The crystal grain growth resistance was evaluated by measuring the crystal grain size after oxidation at 800 ° C. for 100 hours. The resistance to embrittlement was evaluated by calculating [normal temperature elongation after oxidation at 800 ° C. for 100 hours / normal temperature elongation in an unoxidized state] × 100 (%).
なお、これら耐酸化性の評価も試験温度を８００℃に設定しているが、これは本発明材の使用温度を８００℃以下に限定している訳ではない。結果を表１，２に示す。 In this evaluation of oxidation resistance, the test temperature is set to 800 ° C., but this does not limit the use temperature of the material of the present invention to 800 ° C. or less. The results are shown in Tables 1 and 2.
表１，２から次の様に解析できる。 Tables 1 and 2 can be analyzed as follows.
Ｎｏ．１〜４は適正量のＡｌとＳｉを含む本発明のチタン合金であり、例えばＮｏ．１０，１１に示すＡｌ含量が相対的に多い従来タイプの耐熱、耐酸化性チタン合金に比べて高い伸びとエリクセン値を有し、優れた加工性を有しており、しかも純チタンに近い耐食性を有している。更に、純チタンに比べて耐スケールロス性の指標である板厚減少割合が小さく、耐酸素拡散層形成性の指標である最表面近傍の断面硬さも低い。更に、８００℃、１００時間保持後の結晶粒径の成長も小さく、且つ、耐脆化性を示す指標である［８００℃、１００時間保持後の常温伸び／常温伸び］の値も純チタンに比べると格段に高い値を示しており、優れた耐脆化性を有していることが分かる。 No. 1-4 are titanium alloys of the present invention containing appropriate amounts of Al and Si. Compared to conventional heat- and oxidation-resistant titanium alloys with relatively high Al content shown in 10, 11, it has higher elongation and Erichsen value, has excellent workability, and has corrosion resistance close to that of pure titanium. have. Furthermore, the plate thickness reduction rate, which is an index of scale loss resistance, is smaller than that of pure titanium, and the cross-sectional hardness near the outermost surface, which is an index of oxygen resistant diffusion layer formation, is also low. Furthermore, the growth of crystal grain size after holding at 800 ° C. for 100 hours is small, and the value of [Elongation at normal temperature / Elongation at normal temperature after holding at 800 ° C. for 100 hours], which is an index showing embrittlement resistance, is also in pure titanium. Compared to this, the value is markedly high, and it can be seen that it has excellent embrittlement resistance.
これに対しＮｏ．６〜８は、Ａｌの単独添加でＳｉが含まれていないため高温強度が不足気味であり、特に耐高温酸化性（耐スケールロス性、耐酸素拡散層形成性、耐結晶粒成長性、耐脆化性）がＮｏ．１〜４のチタン合金材に比べて劣悪である。Ｎｏ．９は、Ａｌと共にＳｉが含まれているもののその量が少ないため、Ｎｏ．１〜４のチタン合金材に比べると、耐高温酸化性（耐スケールロス性、耐酸素拡散層形成性、耐結晶粒成長性、耐脆化性）も悪い。 In contrast, no. Nos. 6 to 8 have insufficient high-temperature strength because Si is not contained by adding Al alone, and particularly high-temperature oxidation resistance (scale loss resistance, oxygen diffusion layer formation resistance, grain growth resistance, resistance to resistance) No brittleness). It is inferior as compared with 1-4 titanium alloy materials. No. No. 9 contains Si together with Al but its amount is small. Compared with 1-4 titanium alloy materials, the high-temperature oxidation resistance (scale loss resistance, oxygen diffusion layer formation resistance, crystal grain growth resistance, embrittlement resistance) is also poor.
Ｎｏ．１０，１１は、Ａｌを含めた添加合金元素量が相対的に多い従来タイプのＴｉ−Ａｌ系合金であり、添加合金元素量が多いため耐高温酸化性は良好であるが、伸び率およびエリクセン値が低くて成形加工性が劣悪であり、且つ耐食性も悪い。 No. Nos. 10 and 11 are Ti-Al alloys of a conventional type having a relatively large amount of additive alloy elements including Al. Since the amount of additive alloy elements is large, the high-temperature oxidation resistance is good. The value is low, the moldability is poor, and the corrosion resistance is also poor.
実施例２
前記実施例１と同様にして、表３に示す成分組成のチタン合金鋳塊を製造した後、同様の手順で熱間圧延を行い、焼鈍、空冷、酸化スケール除去のための平面研削、更に冷間圧延を行なって厚さ約１ｍｍの供試チタン板を作製し、最終仕上げとして６５０℃×３時間（均熱時間）の真空焼鈍を行った。
Example 2
In the same manner as in Example 1, a titanium alloy ingot having the composition shown in Table 3 was manufactured, followed by hot rolling in the same procedure, annealing, air cooling, surface grinding for removing oxide scale, and further cooling. A test titanium plate having a thickness of about 1 mm was produced by hot rolling, and vacuum annealing was performed at 650 ° C. for 3 hours (soaking time) as a final finish.
得られた各供試板について、実施例１と同様にして引張り試験、エリクセン試験、耐食性試験および耐高温酸化性試験を行い、結果を表３，４に示した。 The obtained test plates were subjected to a tensile test, an Erichsen test, a corrosion resistance test and a high temperature oxidation resistance test in the same manner as in Example 1. The results are shown in Tables 3 and 4.
表３，４において、Ｎｏ．1〜１４（但し、Ｎｏ．１０を除く）は本発明の規定要件を満たす実施例であり、成形加工性、耐食性、耐高温酸化性の全てにおいてバランスの取れた特性が得られている。これに対しＮｏ．１０は、Ａｌ含量が下限値でＳｉ含量が不足する比較材であり、成形加工性や耐食性は良好であるものの、特に耐高温酸化性のうち耐酸素拡散層形成性と耐結晶粒成長性が悪い。なおＮｏ．１５の純チタン材とＮｏ．１６〜２０のチタン合金材は、前記実施例１の表１，２に示したＮｏ．５〜１１に相当するもので、何れも総合的にみると本発明の目的にそぐわない。 In Tables 3 and 4, no. 1 to 14 (excluding No. 10) are examples that satisfy the prescribed requirements of the present invention, and balanced characteristics are obtained in all of moldability, corrosion resistance, and high temperature oxidation resistance. In contrast, no. 10 is a comparative material in which the Al content is the lower limit and the Si content is insufficient, and although the moldability and corrosion resistance are good, the oxygen diffusion layer forming property and the crystal grain growth resistance are particularly high-temperature oxidation resistant. bad. No. No. 15 pure titanium and No. 15 The titanium alloy materials of 16 to 20 are Nos. Shown in Tables 1 and 2 of Example 1. 5 to 11, which are not suitable for the purpose of the present invention when viewed comprehensively.
実施例３
前記実施例１と同様にして、表５に示す成分組成のチタン合金インゴットを製造した後、同様の手順で熱間圧延を行い、焼鈍、空冷、酸化スケール除去のための平面研削、更に冷間圧延を行なって厚さ約１ｍｍの純チタン板を作製し、最終仕上げとして６５０℃×３時間（均熱時間）の真空焼鈍を行った。
Example 3
In the same manner as in Example 1, after producing a titanium alloy ingot having the composition shown in Table 5, hot rolling is performed in the same procedure, annealing, air cooling, surface grinding for removing oxide scale, and further cold working. Rolling was performed to produce a pure titanium plate having a thickness of about 1 mm, and vacuum annealing was performed at 650 ° C. for 3 hours (soaking time) as a final finish.
得られた各供試板について、実施例１と同様にして引張り試験、エリクセン試験、耐食性試験および耐高温酸化性試験を行い、結果を表５，６に示した。 Each of the obtained test plates was subjected to a tensile test, an Erichsen test, a corrosion resistance test, and a high temperature oxidation resistance test in the same manner as in Example 1, and the results are shown in Tables 5 and 6.
これらのチタン合金は、Ａｌ，Ｓｉに加えてＮｂを添加することによる効果を確認するために行なったものであり、ＡｌやＳｉほどにはＮｂ添加による顕著な効果は認められないが、成形加工性にそれほど悪影響を及ぼすことなく耐高温酸化性、特に耐酸素拡散層形成性を高める効果があることを確認できる。 These titanium alloys were used to confirm the effect of adding Nb in addition to Al and Si, and the remarkable effect of Nb addition was not recognized as much as that of Al and Si. It can be confirmed that there is an effect of improving the high temperature oxidation resistance, particularly the oxygen diffusion layer forming property without adversely affecting the properties.
実施例４
前記実施例１と同様にして、表７に示す成分組成のチタン合金鋳塊を製造した後、同様の手順で熱間圧延を行い、焼鈍、空冷、酸化スケール除去のための平面研削、更に冷間圧延を行なって厚さ約１ｍｍの純チタン板を作製し、最終仕上げとして６５０℃×３時間（均熱時間）の真空焼鈍を行った。
Example 4
In the same manner as in Example 1, a titanium alloy ingot having the composition shown in Table 7 was manufactured, followed by hot rolling in the same procedure, annealing, air cooling, surface grinding for removing oxide scale, and further cooling. A pure titanium plate having a thickness of about 1 mm was produced by hot rolling, and vacuum annealing was performed at 650 ° C. for 3 hours (soaking time) as a final finish.
得られた各供試板について、実施例１と同様にして引張り試験、エリクセン試験、耐食性試験および耐高温酸化性試験を行い、結果を表７，８に示した。 The obtained test plates were subjected to a tensile test, an Erichsen test, a corrosion resistance test, and a high temperature oxidation resistance test in the same manner as in Example 1, and the results are shown in Tables 7 and 8.
これらのチタン合金は、Ａｌ，Ｓｉ，Ｎｂに加えてＴａ，Ｗ，Ｍｏ．Ｃｒ，Ｚｒ，Ｈｆを添加することによる効果を確認するために行なったものであり、いずれの元素も引張り強さを僅かに高めて伸びを低下させる傾向がみられるが、その程度は極僅かであり、耐高温酸化性のうち特に耐酸素拡散層形成性と耐脆化性を高める作用が認められる。 These titanium alloys include Ta, W, Mo. in addition to Al, Si, Nb. This was done to confirm the effect of adding Cr, Zr, and Hf, and all the elements tend to slightly increase the tensile strength and decrease the elongation, but the degree is extremely small. In particular, among the high-temperature oxidation resistance, an action for enhancing the resistance to oxygen diffusion layer formation and the embrittlement resistance is recognized.
実施例５
前記実施例２に示した表３のＮｏ．４で得たＴｉ−Ａｌ−Ｓｉ合金板に、下記構成の溶融Ａｌめっき処理を施し、厚さが約２μｍの耐酸化性皮膜を形成した後、実施例１と同様にして引張り試験、エリクセン試験および耐高温酸化性試験を行い、結果を表９，１０に示した。
Example 5
No. 1 in Table 3 shown in Example 2 above. The Ti—Al—Si alloy plate obtained in Step 4 was subjected to a molten Al plating treatment having the following constitution to form an oxidation resistant film having a thickness of about 2 μm, and then a tensile test and an Erichsen test in the same manner as in Example 1. And the high temperature oxidation resistance test was done and the results are shown in Tables 9 and 10.
溶融Ａｌめっき処理：７００℃に加熱溶融したＡｌ溶湯（Ａｌ含量；９７％以上）に、各供試チタン合金板を１０分間浸漬してから引き揚げ、平均膜厚が約２μｍのＡｌめっき層を形成した。 Molten Al plating treatment: Each test titanium alloy plate is immersed for 10 minutes in Al molten metal (Al content: 97% or more) heated and melted at 700 ° C., and then lifted to form an Al plating layer having an average film thickness of about 2 μm. did.
表９，１０からも明らかな様に、本発明の規定要件を満たすＴｉ−Ａｌ−Ｓｉ合金板の表面に、溶融Ａｌめっき皮膜を形成すると、引張り特性、すなわち成形加工性に殆んど悪影響を及ぼすことなく、耐高温酸化性、特に耐酸素拡散層形成性や耐脆化性を有意に改善できることが分かる。 As is clear from Tables 9 and 10, when a molten Al plating film is formed on the surface of a Ti-Al-Si alloy plate that satisfies the prescribed requirements of the present invention, there is almost no adverse effect on tensile properties, that is, moldability. It can be seen that the high-temperature oxidation resistance, in particular, the oxygen diffusion layer forming property and the embrittlement resistance can be improved significantly.
［マフラーへの成形加工］
消耗電極式アーク溶解炉を用いてＴｉ−０．５％Ａｌ−０．６％Ｓｉ合金を溶製し、１トンのインゴットを製造した。これを常法に従って鍛造→熱間圧延→焼鈍→脱スケール→冷間圧延→真空焼鈍の工程を経て板厚０．７５ｍｍのコイルを製造した。この実験で、Ｔｉ−０．５％Ａｌ−０．６％Ｓｉ合金は、ＪＩＳ２種純チタンの製造工程を実質的にそのまま適用して薄板状に加工できた。
[Muffler processing]
Using a consumable electrode type arc melting furnace, a Ti-0.5% Al-0.6% Si alloy was melted to produce a 1 ton ingot. A coil having a thickness of 0.75 mm was manufactured through a process of forging → hot rolling → annealing → descaling → cold rolling → vacuum annealing in accordance with a conventional method. In this experiment, the Ti-0.5% Al-0.6% Si alloy could be processed into a thin plate shape by substantially applying the manufacturing process of JIS type 2 pure titanium as it was.
得られたコイルを使用し、外径５０．８ｍｍおよび６０．５ｍｍの溶接管を製造すると共に、該コイルから切り出したチタン板と溶接し、エキゾーストパイプ、サイレンサーパイプの外筒および内装の一部に用いたバイクマフラーを製造したところ、マフラー組み立てに際して何らの問題も生じなかった。またこのマフラーは、排気管が特に高温となり既存のチタン合金マフラーでは高温酸化によりクラックが入ることが確認されている車種に適用した実車評価試験でも、耐食性や耐高温酸化性に何らのトラブルも生じなかった。 Using the obtained coils, welded pipes with outer diameters of 50.8 mm and 60.5 mm were manufactured, and welded to titanium plates cut out from the coils to form exhaust pipes, silencer pipe outer cylinders and a part of the interior. When the used bike muffler was manufactured, there was no problem in assembling the muffler. In addition, this muffler has some problems in corrosion resistance and high-temperature oxidation resistance even in actual vehicle evaluation tests applied to car models where the exhaust pipe is particularly hot and cracks have been confirmed in existing titanium alloy mufflers due to high-temperature oxidation. There wasn't.
Claims (6)
The titanium alloy according to any one of claims 1 to 5, which is used as a muffler material for automobiles or motorcycles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005026474A JP4516440B2 (en) | 2004-03-12 | 2005-02-02 | Titanium alloy with excellent high-temperature oxidation resistance and corrosion resistance |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004071275 | 2004-03-12 | ||
| JP2005026474A JP4516440B2 (en) | 2004-03-12 | 2005-02-02 | Titanium alloy with excellent high-temperature oxidation resistance and corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005290548A true JP2005290548A (en) | 2005-10-20 |
| JP4516440B2 JP4516440B2 (en) | 2010-08-04 |
Family
ID=35323809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005026474A Expired - Fee Related JP4516440B2 (en) | 2004-03-12 | 2005-02-02 | Titanium alloy with excellent high-temperature oxidation resistance and corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4516440B2 (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100694701B1 (en) | 2005-10-25 | 2007-03-13 | 주식회사 포스코 | Steel sheet having excellent corrosion resistance in muffler of automobile and method for producing the same |
| JP2008115419A (en) * | 2006-11-02 | 2008-05-22 | Nippon Steel Corp | Alpha-type titanium alloy material with excellent workability for exhaust system component, its manufacturing method, and exhaust system member using the alloy |
| DE112007000544T5 (en) | 2006-03-30 | 2009-01-15 | Kabushiki Kaisha Kobe Seiko Sho, Kobe | Titanium material and exhaust pipe for engine |
| WO2011081077A1 (en) | 2009-12-28 | 2011-07-07 | 新日本製鐵株式会社 | Heat-resistant titanium alloy with excellent oxidation resistance for exhaust system components, manufacturing method of heat-resistant titanium plate with excellent oxidation resistance for exhaust system components, and exhaust system |
| JP2013087306A (en) * | 2011-10-14 | 2013-05-13 | Nippon Steel & Sumitomo Metal Corp | Heat-resistant titanium alloy |
| WO2017018519A1 (en) * | 2015-07-29 | 2017-02-02 | 新日鐵住金株式会社 | Titanium composite material, and titanium material for hot working |
| KR20180027572A (en) | 2015-07-29 | 2018-03-14 | 신닛테츠스미킨 카부시키카이샤 | Titanium composites and titanium materials for hot rolling |
| JPWO2017018514A1 (en) * | 2015-07-29 | 2018-05-24 | 新日鐵住金株式会社 | Titanium composite and titanium material for hot rolling |
| TWI641696B (en) * | 2018-02-08 | 2018-11-21 | 日商新日鐵住金股份有限公司 | Titanium alloy |
| US10358698B2 (en) | 2009-12-28 | 2019-07-23 | Nippon Steel Corporation | Heat resistant titanium alloy material for exhaust system part use excellent in oxidation resistance, method of production of heat resistant titanium alloy material for exhaust system part use excellent in oxidation resistance, and exhaust system |
| JPWO2021020532A1 (en) * | 2019-07-30 | 2021-02-04 | ||
| US11066727B2 (en) | 2015-07-29 | 2021-07-20 | Nippon Steel Corporation | Titanium composite material and titanium material for hot working |
| WO2022157844A1 (en) | 2021-01-20 | 2022-07-28 | 日本製鉄株式会社 | Titanium alloy plate and exhaust system component for automobiles |
| CN116656994A (en) * | 2023-07-25 | 2023-08-29 | 成都先进金属材料产业技术研究院股份有限公司 | Method for improving shrinkage strain ratio of TA18 titanium alloy seamless tube and TA18 titanium alloy seamless tube |
| WO2023181654A1 (en) * | 2022-03-24 | 2023-09-28 | 株式会社神戸製鋼所 | Titanium alloy material and production method for titanium alloy component |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5196083B2 (en) | 2011-02-24 | 2013-05-15 | 新日鐵住金株式会社 | High-strength α + β-type titanium alloy hot-rolled sheet excellent in cold coil handling and manufacturing method thereof |
| US9587770B2 (en) | 2011-12-20 | 2017-03-07 | Nippon Steel & Sumitomo Metal Corporation | α + β type titanium alloy sheet for welded pipe, manufacturing method thereof, and α + β type titanium alloy welded pipe product |
| JP6187679B2 (en) | 2014-04-10 | 2017-08-30 | 新日鐵住金株式会社 | Α + β type titanium alloy welded pipe excellent in strength and rigidity in the longitudinal direction of the pipe, and method for producing the same |
| KR101985221B1 (en) * | 2018-11-26 | 2019-06-03 | 주식회사 휴벡셀 | Titanium alloy of darkgray color coated with biocompatibility oxide layer and method of manufacturing the same |
| KR101985224B1 (en) * | 2018-11-26 | 2019-06-03 | 주식회사 휴벡셀 | Manufacturing method of titanium alloy having high surface area by anodic oxidation surface reforming |
| KR101972942B1 (en) * | 2018-11-26 | 2019-04-26 | 주식회사 휴벡셀 | Manufacturing method of titanium alloy with excellent mechanical property and aesthetic impression by anodizing treatment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003055725A (en) * | 2001-08-15 | 2003-02-26 | Kobe Steel Ltd | Titanium alloy with excellent cold workability and fatigue strength after brazing |
-
2005
- 2005-02-02 JP JP2005026474A patent/JP4516440B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003055725A (en) * | 2001-08-15 | 2003-02-26 | Kobe Steel Ltd | Titanium alloy with excellent cold workability and fatigue strength after brazing |
Cited By (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100694701B1 (en) | 2005-10-25 | 2007-03-13 | 주식회사 포스코 | Steel sheet having excellent corrosion resistance in muffler of automobile and method for producing the same |
| DE112007000544B4 (en) | 2006-03-30 | 2018-04-05 | Kabushiki Kaisha Kobe Seiko Sho | Titanium material and exhaust pipe for engine |
| DE112007000544T5 (en) | 2006-03-30 | 2009-01-15 | Kabushiki Kaisha Kobe Seiko Sho, Kobe | Titanium material and exhaust pipe for engine |
| US8431231B2 (en) | 2006-03-30 | 2013-04-30 | Kobe Steel, Ltd. | Titanium Material and Exhaust Pipe for Engine |
| JP2008115419A (en) * | 2006-11-02 | 2008-05-22 | Nippon Steel Corp | Alpha-type titanium alloy material with excellent workability for exhaust system component, its manufacturing method, and exhaust system member using the alloy |
| WO2011081077A1 (en) | 2009-12-28 | 2011-07-07 | 新日本製鐵株式会社 | Heat-resistant titanium alloy with excellent oxidation resistance for exhaust system components, manufacturing method of heat-resistant titanium plate with excellent oxidation resistance for exhaust system components, and exhaust system |
| US10358698B2 (en) | 2009-12-28 | 2019-07-23 | Nippon Steel Corporation | Heat resistant titanium alloy material for exhaust system part use excellent in oxidation resistance, method of production of heat resistant titanium alloy material for exhaust system part use excellent in oxidation resistance, and exhaust system |
| JP2013087306A (en) * | 2011-10-14 | 2013-05-13 | Nippon Steel & Sumitomo Metal Corp | Heat-resistant titanium alloy |
| JPWO2017018514A1 (en) * | 2015-07-29 | 2018-05-24 | 新日鐵住金株式会社 | Titanium composite and titanium material for hot rolling |
| US10920300B2 (en) | 2015-07-29 | 2021-02-16 | Nippon Steel Corporation | Titanium composite material and titanium material for hot rolling |
| JP6094725B1 (en) * | 2015-07-29 | 2017-03-15 | 新日鐵住金株式会社 | Titanium composite and titanium material for hot working |
| US11814703B2 (en) | 2015-07-29 | 2023-11-14 | Nippon Steel Corporation | Titanium material for hot working |
| WO2017018519A1 (en) * | 2015-07-29 | 2017-02-02 | 新日鐵住金株式会社 | Titanium composite material, and titanium material for hot working |
| US11066727B2 (en) | 2015-07-29 | 2021-07-20 | Nippon Steel Corporation | Titanium composite material and titanium material for hot working |
| KR20180027572A (en) | 2015-07-29 | 2018-03-14 | 신닛테츠스미킨 카부시키카이샤 | Titanium composites and titanium materials for hot rolling |
| TWI641696B (en) * | 2018-02-08 | 2018-11-21 | 日商新日鐵住金股份有限公司 | Titanium alloy |
| WO2021020532A1 (en) * | 2019-07-30 | 2021-02-04 | 日本製鉄株式会社 | Titanium alloy plate and exhaust system component of automobiles |
| JPWO2021020532A1 (en) * | 2019-07-30 | 2021-02-04 | ||
| JP7180782B2 (en) | 2019-07-30 | 2022-11-30 | 日本製鉄株式会社 | Titanium alloy plate and automobile exhaust system parts |
| WO2022157844A1 (en) | 2021-01-20 | 2022-07-28 | 日本製鉄株式会社 | Titanium alloy plate and exhaust system component for automobiles |
| WO2023181654A1 (en) * | 2022-03-24 | 2023-09-28 | 株式会社神戸製鋼所 | Titanium alloy material and production method for titanium alloy component |
| CN116656994A (en) * | 2023-07-25 | 2023-08-29 | 成都先进金属材料产业技术研究院股份有限公司 | Method for improving shrinkage strain ratio of TA18 titanium alloy seamless tube and TA18 titanium alloy seamless tube |
| CN116656994B (en) * | 2023-07-25 | 2023-10-13 | 成都先进金属材料产业技术研究院股份有限公司 | Method for improving shrinkage strain ratio of TA18 titanium alloy seamless tube and TA18 titanium alloy seamless tube |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4516440B2 (en) | 2010-08-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4516440B2 (en) | Titanium alloy with excellent high-temperature oxidation resistance and corrosion resistance | |
| US7166367B2 (en) | Titanium alloy having excellent high-temperature oxidation and corrosion resistance | |
| JP6541869B2 (en) | Austenitic stainless steel plate and turbocharger part for exhaust parts excellent in heat resistance and processability, and manufacturing method of austenitic stainless steel sheet for exhaust parts | |
| JP5177330B1 (en) | Carburization-resistant metal material | |
| KR101454458B1 (en) | Heat-resistant titanium alloy with excellent oxidation resistance for exhaust system components, manufacturing method of heat-resistant titanium plate with excellent oxidation resistance for exhaust system components, and exhaust system | |
| JP5218703B2 (en) | Hot-dip Al-plated steel sheet excellent in heat blackening resistance and method for producing the same | |
| JP2715082B2 (en) | Manufacturing method of ferritic stainless steel | |
| JP4390089B2 (en) | Ni-based alloy | |
| KR20100035700A (en) | Al-plated steel sheet for exhaust gas passageway members of motorcycles excellent in high-temperature strength and members | |
| WO2021100687A1 (en) | Ferritic stainless steel sheet | |
| KR20100035694A (en) | Al-plated steel sheet for exhaust gas passageway members of motorcycles and members | |
| JP4986975B2 (en) | Al-containing heat-resistant ferritic stainless steel sheet excellent in workability and oxidation resistance and method for producing the same | |
| WO2002103072A1 (en) | Metal material having good resistance to metal dusting | |
| JP4431194B2 (en) | Al-Mg alloy products for welded structures | |
| JP4850662B2 (en) | Α-type titanium alloy material for exhaust system parts excellent in workability, manufacturing method thereof, and exhaust device member using the alloy | |
| JP6858056B2 (en) | Low specific gravity ferritic stainless steel sheet and its manufacturing method | |
| JP5183916B2 (en) | Solid wire for ferritic stainless steel welding | |
| JP2004197150A (en) | Metal dusting resistant metallic material having excellent high temperature strength | |
| JP6778621B2 (en) | Austenitic stainless steel sheet for exhaust parts and its manufacturing method, and exhaust parts and their manufacturing method | |
| JP2014111265A (en) | Cladding powder alloy | |
| JP2002249838A (en) | CORROSION-RESISTANT AND HEAT-RESISTANT Ni ALLOY FOR FOSSIL FUEL COMBUSTION EQUIPMENT | |
| JP2896077B2 (en) | Ferrite stainless steel with excellent high-temperature oxidation resistance and scale adhesion | |
| JP2019059995A (en) | Austenitic stainless steel plate having excellent heat resistance and method for producing the same | |
| JP2022098633A (en) | Austenitic stainless steel sheet, method for producing austenitic stainless steel sheet and automobile exhaust component | |
| RU2458175C1 (en) | Ferrite stainless steel with high hot-resistance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20070928 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20090911 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090929 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20091130 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100511 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100514 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4516440 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130521 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140521 Year of fee payment: 4 |
|
| LAPS | Cancellation because of no payment of annual fees |