JPH0344449A - Stainless steel shape and its production - Google Patents
Stainless steel shape and its productionInfo
- Publication number
- JPH0344449A JPH0344449A JP18007389A JP18007389A JPH0344449A JP H0344449 A JPH0344449 A JP H0344449A JP 18007389 A JP18007389 A JP 18007389A JP 18007389 A JP18007389 A JP 18007389A JP H0344449 A JPH0344449 A JP H0344449A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- less
- stainless steel
- temperature
- austenitic stainless
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 25
- 229910001220 stainless steel Inorganic materials 0.000 title abstract description 4
- 239000010935 stainless steel Substances 0.000 title abstract description 4
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 59
- 239000010959 steel Substances 0.000 claims abstract description 59
- 229910000963 austenitic stainless steel Inorganic materials 0.000 claims abstract description 31
- 238000001816 cooling Methods 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 19
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 14
- 239000000203 mixture Substances 0.000 claims abstract description 13
- 229910000734 martensite Inorganic materials 0.000 claims abstract description 12
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 11
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 9
- 239000012535 impurity Substances 0.000 claims abstract description 8
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 5
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 4
- 238000005096 rolling process Methods 0.000 claims description 46
- 238000010438 heat treatment Methods 0.000 claims description 12
- 229910052758 niobium Inorganic materials 0.000 claims description 6
- 229910052720 vanadium Inorganic materials 0.000 claims description 5
- 230000007797 corrosion Effects 0.000 abstract description 29
- 238000005260 corrosion Methods 0.000 abstract description 29
- 238000003303 reheating Methods 0.000 abstract description 4
- 238000005098 hot rolling Methods 0.000 abstract description 3
- 229910052759 nickel Inorganic materials 0.000 abstract description 3
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 238000009435 building construction Methods 0.000 abstract 1
- 238000001953 recrystallisation Methods 0.000 description 20
- 238000012360 testing method Methods 0.000 description 17
- 239000000463 material Substances 0.000 description 16
- 230000015572 biosynthetic process Effects 0.000 description 15
- 150000001247 metal acetylides Chemical class 0.000 description 13
- 229910001566 austenite Inorganic materials 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 238000012545 processing Methods 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- 238000001556 precipitation Methods 0.000 description 6
- 238000005452 bending Methods 0.000 description 5
- 238000005482 strain hardening Methods 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000005336 cracking Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 230000002950 deficient Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000010953 base metal Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- BQJTUDIVKSVBDU-UHFFFAOYSA-L copper;sulfuric acid;sulfate Chemical compound [Cu+2].OS(O)(=O)=O.[O-]S([O-])(=O)=O BQJTUDIVKSVBDU-UHFFFAOYSA-L 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000007730 finishing process Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は建築構造部材に使用されるオーステナイト系ス
テンレス鋼製の形鋼、即ち、Ｈ形鋼、山形鋼、溝形鋼や
鋼矢板等とそれらの製造方法に関する。Detailed Description of the Invention (Field of Industrial Application) The present invention applies to austenitic stainless steel sections used for building structural members, such as H sections, angle sections, channel sections, and steel sheet piles. Regarding their manufacturing method.
（従来の技術）
建築用構造部材に使用される鋼材は、建築基準法により
定められているが、その規定の中にステンレス鋼の形鋼
は入っていない、これはステンレス鋼が構造用部材とし
ての特性をもたないためというより、その価格に問題が
あり構造部材として用いるには余りに高価すぎたことに
起因しているといってよい、しかし近年の急激な地価高
騰はその上に建てられる建築物の相対的なコストを低下
させ、建築構造材料として比較的高価なものも使用され
るようになってきた０例えば、都市中心部の建築物は、
従来のコスト意識に基づく設計とは異なり、景観あるい
は機能を重んじる思想の基に設計される傾向にある。(Prior art) Steel materials used in structural members for buildings are regulated by the Building Standards Act, but stainless steel sections are not included in the regulations. It can be said that this is due to the fact that it is too expensive to be used as a structural member, rather than because it does not have the characteristics of The relative cost of buildings has been reduced, and relatively expensive materials have come to be used as structural materials.0For example, buildings in urban centers are
Unlike conventional designs based on cost consciousness, they tend to be designed based on ideas that emphasize landscape or function.
上記のような傾向に沿う動きとして、通産省生活産業局
の諮問機関としての「景観材料研究会Ｊや建設省の「総
合技術開発プロジェクト」等の活動がある。特に後者に
おいては、昭和６１年４月にステンレス協会に設置され
た「構造材設計施工基準作戒小委員会」で２年６力月に
わたり調査および実験研究が行われ、景観の美しいオー
ステナイト系ステンレス鋼を構造用部材として適用しよ
うとする試みがなされ、オーステナイト系ステンレス鋼
（ＪＩＳ ５ＵＳ３０４）を建築用構造部材として用い
るに際しての必要な機械的性質が明示された。その内容
は０．１％耐力が２４ｋｇｆ／ａｍ”以上、引張強さが
５３ｋｇｆ／ａ＋ｍ”以上、降伏比が０．６０以下、伸
びが３５％以上、というものである。As movements in line with the above trends, there are activities such as the ``Landscape Materials Study Group J'', an advisory body of the Ministry of International Trade and Industry's Lifestyle Industry Bureau, and the ``Comprehensive Technology Development Project'' of the Ministry of Construction. In particular, regarding the latter, the ``Structural Material Design and Construction Standards Subcommittee'' established at the Stainless Steel Association in April 1986 conducted surveys and experimental research for two years and six months. Attempts have been made to apply steel as a structural member, and the mechanical properties necessary for using austenitic stainless steel (JIS 5US304) as a structural member for construction have been clarified. The details are that the 0.1% proof stress is 24 kgf/am'' or more, the tensile strength is 53 kgf/a+m'' or more, the yield ratio is 0.60 or less, and the elongation is 35% or more.
しかし、現在製造されているオーステナイト系ステンレ
ス鋼材は必ずしもこの機械的性質を満足しているとは限
らない、その中で特に問題視されるのはＨ形鋼を代表と
する圧延形鋼である。一般にオーステナイト系ステンレ
ス鋼は耐食性改善を目的として溶体化処理が行われるが
、圧延形鋼は他の板材、棒、線材のような冷間での矯正
工程を経ないため降伏点が低い、前記の０．１％耐力を
保証するには冷間加工設備を新たに導入し、溶体化処理
後に冷間加工を施して強度を上げる必要がある。しかし
、形鋼はその断面形状が複雑であるから、冷間加工は難
しくその加工設備も精緻なものが必要で、設備導入費は
膨大なものとなり実現性に乏しい、圧延形鋼を建築用構
造部材に適用するためには、冷間加工設備の新設を必要
としない低コストの製造方法でその耐力をはじめとする
機械的強度を向上させることが必要である。However, currently manufactured austenitic stainless steel materials do not necessarily satisfy these mechanical properties, and among them, rolled section steels such as H-section steels are particularly problematic. Generally, austenitic stainless steel is subjected to solution treatment to improve its corrosion resistance, but rolled section steel does not go through the cold straightening process like other plates, bars, and wires, so it has a low yield point. To guarantee 0.1% yield strength, it is necessary to introduce new cold working equipment and perform cold working after solution treatment to increase strength. However, since shaped steel has a complex cross-sectional shape, it is difficult to cold-work it, requiring sophisticated processing equipment, and the equipment installation costs are enormous, making it difficult to implement. In order to apply it to parts, it is necessary to improve its mechanical strength, including its yield strength, using a low-cost manufacturing method that does not require the installation of new cold working equipment.
（発明が解決しようとする課題）
オーステナイト系ステンレス鋼の耐力を向上させる手法
としては、圧延（熱間圧延）による加工歪の導入が考え
られる。しかし、通常のオーステナイト系ステンレス鋼
では、圧延のままでは粒界の炭化物の生成を抑えること
ができず、粒界のＣ「欠乏層に起因する耐食性の低下を
免れない、オーステナイトステンレス鋼本来の耐食性を
保証するには、どうしても溶体化処理を行わなければな
らず、そうすると耐力が大きく低下してしまう、溶体化
処理の後に冷間加工を施せば耐力は回復するが、形鋼の
冷間加工には大きな難点があることは前述のとおりであ
る。(Problems to be Solved by the Invention) One possible method for improving the yield strength of austenitic stainless steel is to introduce processing strain through rolling (hot rolling). However, in ordinary austenitic stainless steel, it is not possible to suppress the formation of carbides at the grain boundaries when it is rolled, and the corrosion resistance of austenitic stainless steel is inevitably reduced due to the C-deficient layer at the grain boundaries. In order to guarantee the As mentioned above, there are major drawbacks.
本発明の課題は、オーステナイト系ステンレス鋼本来の
耐食性を備え、しかも前記の強度基準を満足する形鋼を
提供すること、およびそのような形鋼を溶体化処理を行
わず、従って、その後の冷間加工も必要とせずに製造す
る方法を提供することにある。An object of the present invention is to provide a section steel that has the corrosion resistance inherent to austenitic stainless steel and also satisfies the above-mentioned strength standards, and to provide such a section steel without solution treatment and, therefore, without subsequent cooling. The object is to provide a manufacturing method that does not require additional machining.
（課題を解決するための手段）
前記の強度基準、特に０．１％耐力で２４ｋｇｆ／＋＊
ｍ”以上を満足するオーステナイト系ステンレス形鋼を
低コストで製造するに′は、圧延のままでも充分な耐食
性をもつように材質と加工方法を工夫する必要がある。(Means for solving the problem) The above-mentioned strength standards, especially 24 kgf/+* with 0.1% yield strength
In order to manufacture austenitic stainless steel sections that meet the requirements of 50 m or more at a low cost, it is necessary to devise materials and processing methods so that they have sufficient corrosion resistance even when rolled.
即ち、圧延のままで優れた耐食性をもつものであれば、
溶体化処理を施す必要がなく、従って、圧延によって得
られた高強度が失われないから、高強度化のための冷間
加工が不必要になる。この場合、圧延条件は形鋼に前記
基準を満足する強度と溶体化材に匹敵する耐食性を与え
ることができるような条件を選ばなければならない。In other words, if it has excellent corrosion resistance as rolled,
Since there is no need to perform solution treatment and therefore the high strength obtained by rolling is not lost, cold working for increasing the strength is unnecessary. In this case, the rolling conditions must be selected so as to give the section steel strength that satisfies the above criteria and corrosion resistance comparable to that of solution-treated steel.
オーステナイトステンレス鋼の耐力を向上させるにはオ
ーステナイト粒（７粒）の細粒化をはかることが必要で
ある。また、耐食性を向上させるには粒界の炭化物の生
成を抑えＣｒ欠乏層が形成されるのを抑制することが必
要である０本発明者らはこれらの条件を満たす加工方法
を探究し、下記のような知見を得た。即ち、
■ ７粒の細粒化については、８５０℃以上の高温仕上
圧延を行い圧延による再結晶を利用するか、あるいは圧
延後に急速加熱と短時間加熱保持を行うことにより圧延
を通じて導入された加工歪を利用し再結晶を促進するこ
とが効果的である。In order to improve the yield strength of austenitic stainless steel, it is necessary to make the austenite grains (7 grains) finer. In addition, in order to improve corrosion resistance, it is necessary to suppress the formation of carbides at grain boundaries and to suppress the formation of Cr-depleted layers. We obtained the following knowledge. In other words, ■ 7 grains can be refined by performing high-temperature finishing rolling at 850°C or higher and recrystallizing the material by rolling, or by performing rapid heating and short-term heating and holding after rolling to achieve processing introduced through rolling. It is effective to promote recrystallization using strain.
■ 圧延のままでは粒界の炭化物の生成を抑制すること
は難しい、しかし、粒界の炭化物の生成はその綱の炭素
含有量に依存し、炭素含有量を０．０３％以下に抑える
ことにより圧延のままの状態でも粒界の炭化物の生成を
抑制し得る。■ It is difficult to suppress the formation of carbides at the grain boundaries if the steel is rolled, but the formation of carbides at the grain boundaries depends on the carbon content of the steel, and by suppressing the carbon content to 0.03% or less. Even in the as-rolled state, the formation of carbides at grain boundaries can be suppressed.
■ 炭化物の生成に先立ち再結晶を先行させると粒界の
炭化物の生成が遅くなる。■ If recrystallization is performed prior to the formation of carbides, the formation of carbides at grain boundaries will be delayed.
以上の知見を基にしてなされた本発明は、下記の（１）
〜（４）をその要旨とする。The present invention, which was made based on the above knowledge, has the following (1)
~(4) is the gist.
（１）重量％で、Ｃ：０．０３％以下、Ｓｉ： ｔ、ｏ
ｏ％以下、Ｍｎ：０．３０〜２．００％、Ｐ ：０．０
４０％以下、Ｓ ：０．０３％以下、Ｃｒ： １７〜２
０％、Ｎｉニア、０〜１０．５％、Ｎ：０．０６〜０．
１４％を含有し残部Ｆｅおよび不可避的不純物からなり
、残留フェライトまたはマルテンサイトの量が１０％以
下で、０．１％耐力が２４Ｋｇｆ／ｇ＋ｎ”以上”？’
することを特徴とする建築構造部材用オーステナイト
系ステンレス形鋼。(1) In weight%, C: 0.03% or less, Si: t, o
o% or less, Mn: 0.30-2.00%, P: 0.0
40% or less, S: 0.03% or less, Cr: 17-2
0%, Ni near, 0-10.5%, N: 0.06-0.
14%, the balance consists of Fe and unavoidable impurities, the amount of residual ferrite or martensite is 10% or less, and the 0.1% proof stress is 24Kgf/g+n" or more"? '
An austenitic stainless steel shape steel for building structural members, which is characterized by:
（２）上記（１）の成分に加えてさらに、Ｍｏ：０．０
５〜０．７０％、Ｎｂ：０．Ｏ０５〜ｏ、ｏａｏ％、Ｖ
：０．００５〜０．１５％、Ｃｕ：０．１０〜０．５
０％、およびＴｉ：０．００５〜０．６０％、のうちの
１種以上を含有し残部Ｆｅおよび不可避的不純物からな
り、残留フェライトまたはマルテンサイトの合計量が１
０％以下で、０．１％耐力が２４にｇ４７ｍｍ”以上で
あることを特徴とする建築構造部材用オーステナイト系
ステンレス形鋼。(2) In addition to the components in (1) above, Mo: 0.0
5-0.70%, Nb:0. O05~o, oao%, V
:0.005~0.15%, Cu:0.10~0.5
0%, and Ti: 0.005 to 0.60%, with the balance consisting of Fe and unavoidable impurities, and the total amount of residual ferrite or martensite is 1.
0% or less and a 0.1% yield strength of 24 g47 mm or more.
（３）上記（１）または（２）記載の組成をもつ鋼を１
０００〜１２５０℃の温度域で加熱して粗圧延を施した
後、再度１０００〜１２５０℃の温度に加熱して熱間加
工を施し、８５０〜１０００℃以上の温度域で所定の形
状の形鋼に成形した後空冷することを特徴とする請求項
（１）または（２）の建築構造部材用オーステナイト系
ステンレス形鋼の製造方法。(3) Steel having the composition described in (1) or (2) above
After heating in a temperature range of 000 to 1250°C and rough rolling, heating again to a temperature of 1000 to 1250°C and hot working, forming a section steel into a predetermined shape in a temperature range of 850 to 1000°C or higher. The method for manufacturing an austenitic stainless steel section for building structural members according to claim 1 or 2, characterized in that the austenitic stainless steel section is air-cooled after being formed into a shape.
（４）上記（１）または（２）記載の組成をもつ鋼を１
０００〜１２５０℃の温度域で加熱し、仕上温度が９０
０℃以下になる条件で熱間加工を施して所定の形状の形
鋼に成形し、直ちに９００〜１１００℃以上の温度で１
〜６０分の間等温保持した後、空冷以上の冷却速度で冷
却することを特徴とする請求項（１）または（２）の建
築構造部材用オーステナイト系ステンレス形鋼の製造方
法。(4) Steel having the composition described in (1) or (2) above
Heating in the temperature range of 000 to 1250℃, the finishing temperature is 90℃.
Hot working is performed at a temperature of 0°C or lower to form a section steel into a specified shape, and then immediately heated to a temperature of 900 to 1100°C or higher.
The method for producing an austenitic stainless steel section for building structural members according to claim 1 or 2, characterized in that after holding the temperature isothermally for ~60 minutes, the austenitic stainless steel section is cooled at a cooling rate higher than air cooling.
本発明の形鋼は、先に述べた強度基準、即ち、０．１％
耐力が２４１［ｇｆ／＋ｗｇ＋”以上、引張強さが５３
Ｋｇｆ／ｖｉ’以上、降伏比が０．６０以下、伸びが３
５％以上であり、かつ溶体化材と同等以上の耐食性を併
せもつオーステナイト系ステンレス形鋼である。そして
その用途は、建築構造部材である。The steel section of the present invention meets the strength standard mentioned above, that is, 0.1%
Proof strength is 241 [gf/+wg+” or more, tensile strength is 53
Kgf/vi' or more, yield ratio 0.60 or less, elongation 3
5% or more, and is an austenitic stainless steel section with corrosion resistance equal to or higher than that of solution-treated steel. Its use is as a building structural member.
本発明の製造方法は、上記のような形鋼を、溶体化処理
や冷間加工の工程なしで製造する方法である。以下、そ
れぞれについて詳しく説明する。The manufacturing method of the present invention is a method for manufacturing the above-described shaped steel without any solution treatment or cold working steps. Each will be explained in detail below.
（作用）
先ず、本発明の形鋼の化学組成について説明する。なお
、成分含有量についての％は重量％を意味する。(Function) First, the chemical composition of the shaped steel of the present invention will be explained. In addition, % regarding component content means weight %.
Ｃ： ０．０３以下
Ｃはオーステナイト相を安定化させる元素であるが、鋼
中に０．０３％を超えて含有されると粒界への炭化物の
優先析出を抑制することができず、熱的履歴によっては
粒界近傍にＣｒの欠乏層を生じ耐食生の低下が生じる。C: 0.03 or less C is an element that stabilizes the austenite phase, but if it is contained in steel in an amount exceeding 0.03%, preferential precipitation of carbides at grain boundaries cannot be suppressed and Depending on the corrosion history, a Cr-deficient layer may be formed near the grain boundaries, resulting in a decrease in corrosion resistance.
そのため、Ｃ含有量は０．０３％以下とする。Therefore, the C content is set to 0.03% or less.
Ｓｉ： １．００％以下
Ｓｌは製鋼時の脱酸剤として必要とされるが、１゜００
％を超える含有量になると延性の劣化が顕著になる。従
ってＳＩの含有量は１．００％以下とする。Si: 1.00% or less Sl is required as a deoxidizing agent during steel manufacturing, but 1.00% or less
When the content exceeds %, the deterioration of ductility becomes noticeable. Therefore, the content of SI is set to 1.00% or less.
Ｍｎ： ０．３０〜２．００％
Ｍｎはオーステナイト生成元素であり、かつ鋼中のＳを
ＭｎＳとして固定し熱間での加工性を改善する。そのた
めには０．３０％以上の含有が必要であるが、２％を超
えて含有させても効果の増大がなく材料価格の上昇を招
くだけである。従って、Ｍｎの含有量は０．３０〜２．
００％とする。Mn: 0.30-2.00% Mn is an austenite-forming element, and fixes S in steel as MnS to improve hot workability. For this purpose, the content must be 0.30% or more, but even if the content exceeds 2%, the effect will not increase and the price of the material will only increase. Therefore, the Mn content is between 0.30 and 2.
00%.
Ｐ：０．０４０％以下
Ｐは不可避的不純物として鋼中に含まれる元素であり、
少ない方が望ましいが製造コストを加味してＰの許容上
限値は０．０４％とする。P: 0.040% or less P is an element contained in steel as an unavoidable impurity,
Although it is preferable to have a smaller amount, the allowable upper limit of P is set at 0.04% in consideration of manufacturing costs.
Ｓ：０．０３０％以下
ＳはＰと同様に不可避的不純物として鋼中に含まれる元
素であり、粒界に低融点化合物として析出して熱間加工
性を著しく低下させる。Ｓの含有量も低いほど好ましい
が０．０３％以下とすると熱間加工性にも特に問題がな
くなるので許容上限値を０．０３０％とする。より望ま
しいのは０．０１０％以下である。S: 0.030% or less S, like P, is an element contained in steel as an unavoidable impurity, and precipitates at grain boundaries as a low melting point compound, significantly reducing hot workability. The lower the S content is, the more preferable it is, but if it is 0.03% or less, there will be no particular problem with hot workability, so the allowable upper limit is set at 0.030%. A more desirable content is 0.010% or less.
Ｃｒ： １７〜２０％ Ｃｒは耐食性を保証するためには不可欠な元素である。Cr: 17-20% Cr is an essential element to ensure corrosion resistance.
１７％未満では十分な耐食性が得られない。If it is less than 17%, sufficient corrosion resistance cannot be obtained.
一方、２０％を超えて含有されると、後述の理由でフェ
ライトの生成を１０％以下に抑制するために、Ｍｌの添
加量を高くすることが必要になって、製造コストを著し
く高める。従って、Ｃｒの適正含有量は１７〜２０％で
ある。On the other hand, if the Ml content exceeds 20%, it becomes necessary to increase the amount of Ml added in order to suppress the formation of ferrite to 10% or less for reasons described later, which significantly increases manufacturing costs. Therefore, the appropriate content of Cr is 17 to 20%.
Ｎｉ： ７．０〜１０．５％
Ｎｌはオーステナイト系ステンレス鋼を槽底する基本元
素であり、かつ耐食性を向上させる元素である。そのた
めには７．０％以上の含有が必要である。ただし１０．
５％を超えて含有させても材料価格を上げるだけで耐食
性改善効果は飽和傾向を示すためその含有量を７．００
〜１０．５％とする。Ni: 7.0 to 10.5% Ni is a basic element that forms the bottom of austenitic stainless steel and is an element that improves corrosion resistance. For this purpose, the content must be 7.0% or more. However, 10.
If the content exceeds 5%, it will only increase the material price and the corrosion resistance improvement effect will tend to be saturated, so the content should be reduced to 7.00%.
~10.5%.
Ｎ ： ０．０６〜０．１４％
Ｎ（窒素）は、オーステナイトの安定化元素であり、０
．０６〜０．１４％の含有により高価なＮｉを代替して
鋼のオーステナイトバランスを保つのに役立ち、残留フ
ェライトやマルテンサイトの量を１０％以下に抑える作
用をもつ、しかし、０．１４％を超える含有量になると
、連続鋳造鋼片の表面割れが増加し、歩留り低下による
製造コストの上昇を招く。N: 0.06-0.14% N (nitrogen) is an austenite stabilizing element, and
．． The content of 0.6 to 0.14% helps to maintain the austenite balance of steel by replacing expensive Ni, and has the effect of suppressing the amount of residual ferrite and martensite to 10% or less. If the content exceeds this amount, surface cracking of continuously cast steel pieces increases, leading to a decrease in yield and an increase in manufacturing costs.
Ｎが０．０６％未満では、オーステナイトバランスを適
正に保つのに必要なＮｉｌが増えて、やはりコスト上昇
になる。If the N content is less than 0.06%, the amount of Nil required to properly maintain the austenite balance increases, resulting in an increase in cost.
以上の成分の外、残部はＦｅおよび不可避の不純物から
戒るのが前記（１）の形鋼である。これに対し、さらに
高靭性あるいは高強度を要求される場合には、次にのべ
る含有量の範囲でＭｏ、 Ｎｂ、 Ｖ、 Ｃｕ。In addition to the above-mentioned components, the remainder should be Fe and unavoidable impurities in the shaped steel of (1) above. On the other hand, if higher toughness or strength is required, Mo, Nb, V, and Cu may be added within the following content ranges.
Ｔｉのうち１種または２種以上を含有させることができ
る。One or more types of Ti can be contained.
Ｎｏ： ０．０５〜０．７０％
Ｍｏは強度を高めるのに有効な元素であり、この効果を
期待する場合は０．０５％以上含有させる必要がある。No.: 0.05 to 0.70% Mo is an effective element for increasing strength, and if this effect is expected, it must be contained in an amount of 0.05% or more.
しかしその含有量が０．７０％を超えると過量のフェラ
イトが生じる場合があるから、上限は０．７０％までと
するのがよい。However, if the content exceeds 0.70%, an excessive amount of ferrite may be produced, so the upper limit is preferably 0.70%.
Ｎｂ：０．００５〜０．０８０％
Ｎｂは強度を上昇させる元素である。そのためにはｏ、
ｏｏｓ％以上含有させる必要があるが、０．０８０％を
超えるとオーステナイト粒の再結晶を抑制する作用が顕
れ、再結晶を促進してオーステナイト粒の細粒化をはか
ることにより高強度化しようとする本発明の目的に反す
る。Nb: 0.005-0.080% Nb is an element that increases strength. For that purpose,
It is necessary to contain oos% or more, but if it exceeds 0.080%, the effect of suppressing the recrystallization of austenite grains appears, and it is attempted to increase the strength by promoting recrystallization and making the austenite grains finer. This is contrary to the purpose of the present invention.
Ｖ： ０．００５〜０．１５％ ■はＮｂと同様に強度を上昇させる元素である。V: 0.005-0.15% (2) is an element that increases strength like Nb.
そのためには０．００５％以上の含有が必要であるが、
０．１５％を超えてもその効果の増大がなく、材料価格
の上昇を招くだけであるから０．００５〜０．１５％が
適当である。For that purpose, it is necessary to contain 0.005% or more,
If it exceeds 0.15%, the effect will not increase and the material price will only increase, so 0.005 to 0.15% is appropriate.
Ｃｕ： ０．１０〜０．５０％
Ｃｕは高温強度を向上させかつ耐食性を改善するのに有
効な元素であるが、そのためには０．１０％以上含有さ
せる必要がある。しかし、０．５％を超えると圧延の際
の表面割れが増大し、また、溶接割れを助長する傾向が
ある。Cu: 0.10-0.50% Cu is an effective element for improving high-temperature strength and corrosion resistance, but for this purpose it is necessary to contain it at 0.10% or more. However, if it exceeds 0.5%, surface cracking during rolling increases and there is a tendency to promote weld cracking.
Ｔｉ：０．００２〜０．６０％ Ｔｉは■、Ｎｂと同様に強度を上昇させる元素である。Ti: 0.002-0.60% Ti is an element that increases the strength similarly to (1) and Nb.
そのためには０．００２％以上の含有が必要であるが０
．６０％を超えると母材の靭性を損なうので、０．００
２〜０．６０％が適正含有量である。For that purpose, it is necessary to contain 0.002% or more, but 0.
．． If it exceeds 60%, the toughness of the base material will be impaired, so 0.00%
The appropriate content is 2 to 0.60%.
次に、本発明形鋼の金属学的組織について述べる０本発
明の形鋼はオーステナイト系ステンレス鋼からなるもの
である。従って、その組織は完全オーステナイトである
ことを原則とするが、体積％で１０％以下のフェライト
、またはマルテンサイトを含んでいても差し支えない。Next, the metallurgical structure of the shaped steel of the present invention will be described. The shaped steel of the present invention is made of austenitic stainless steel. Therefore, in principle, the structure is completely austenite, but it may contain 10% or less of ferrite or martensite by volume.
残留フェライトとマルテンサイトの生成量は、鋼の化学
組成と製造条件（本発明方法の場合は、圧延中および圧
延後の冷却条件、および再加熱を行う場合はその条件）
に依存する。残留フェライトやマルテンサイトが存在す
れば、製品形鋼の強度が高くなるが、一方では延性を低
下させる。これらの量が体積で１０％を超える場合、延
性の低下が顕著になり、特に溶接部周辺の応力集中部で
割れが発生しやすく、構造用部材としては不適当である
。The amount of residual ferrite and martensite produced depends on the chemical composition of the steel and manufacturing conditions (in the case of the method of the present invention, the cooling conditions during and after rolling, and if reheating is performed, the conditions)
Depends on. If residual ferrite or martensite exists, the strength of the product section steel will increase, but on the other hand, it will reduce the ductility. If the amount exceeds 10% by volume, the ductility decreases significantly and cracks are likely to occur particularly in the stress concentration area around the weld, making it unsuitable for use as a structural member.
化学組成上、残留フェライトまたはマルテンサイトを１
０％以下に抑えるのに望ましい条件は、Ｎｉ当量（Ｎｉ
ｅｑ）≧０．９ＸＣｒ当！（Ｃｒｅｑ） −７，２−（
ａ）Ｎｌ当量（Ｎｌｅｑ）≧−Ｑ、３ＸＣｒ当量（Ｃｒ
ｅｑ） ＋ ２５ ・・・（ｂ）の両式を満足すること
である。（ａ）式は残留フェライトを１０％以下にする
ための条件、（ロ）式はマルテンサイトの生成を１０％
以下にする条件である。Due to chemical composition, residual ferrite or martensite is 1
The desirable conditions for suppressing it to 0% or less are Ni equivalent (Ni
eq) ≧0.9XCr! (Creq) -7,2-(
a) Nl equivalent (Nleq)≧-Q, 3X Cr equivalent (Cr
eq) + 25...Both equations in (b) are to be satisfied. Equation (a) is the condition for reducing residual ferrite to 10% or less, and equation (b) is for reducing the generation of martensite to 10%.
The conditions are as follows.
但し、
Ｎ１ｅｑ−Ｎｉχ＋３０ＸＣＸ＋３０ＸＮχ＋０．５Ｘ
ＭｎＸＣｒｅｑ ｍ Ｃｒχ十勅χ＋１．５ＸＳｉＸ＋
０．５ＸＮｂχである。However, N1eq-Niχ+30XCX+30XNχ+0.5X
MnXCreq m Crχ10x+1.5XSiX+
It is 0.5XNbχ.
以下、本発明の形鋼の製造方法について説明する。Hereinafter, the method for manufacturing a section steel of the present invention will be explained.
第１図および第２図は、本発明の形鋼の製造方法におけ
るヒートパターンの説明図である。FIGS. 1 and 2 are explanatory diagrams of heat patterns in the method for manufacturing a section steel of the present invention.
先ず、第１図によって説明する。First, the explanation will be given with reference to FIG.
先にも述べたように、８５０℃以上の高温仕上圧延を行
い圧延による再結晶を利用すると、溶体化処理材に比し
γ粒が細粒化され耐力が向上する。As mentioned earlier, when high-temperature finish rolling is performed at 850° C. or higher and recrystallization due to rolling is utilized, the γ grains are made finer and the yield strength is improved compared to the solution-treated material.
しかし、−ａに形鋼の圧延は複雑なパススケジュールと
なるため８５０℃以上の高温の仕上げ温度を確保するこ
とは困難である。そこで、第１図の方法では、粗圧延後
回加熱する方法を採用する。However, since rolling of section steel requires a complicated pass schedule, it is difficult to ensure a high finishing temperature of 850° C. or higher. Therefore, in the method shown in FIG. 1, a method of heating after rough rolling is adopted.
第１図において、粗圧延の前の加熱（ａ）はｔｏｏｏ〜
１２５０℃で行う、この温度は１０００″Ｃ以上として
おかないとＮｂ、 Ｖなどの炭窒化物の固溶が図れない
ため、これらの析出強化を利用することができなくなる
。一方、Ｎｂ、 Ｖなどの合金成分を含まない成分系で
も、オーステナイト系ステンレス鋼は熱間変形抵抗が高
いため、１０００℃以上の温度に加熱しておかないと所
定の形状に成形加工することができない、但し１２５０
″Ｃを超える温度で加熱すると圧延初期１粒の粗大化に
つながり、圧延による再結晶を利用する細粒化の効果が
小さくなる。In Fig. 1, heating (a) before rough rolling is too~
It is carried out at 1250°C. Unless this temperature is set to 1000"C or higher, solid solution of carbonitrides such as Nb and V cannot be achieved, making it impossible to utilize their precipitation strengthening. On the other hand, when carbonitrides such as Nb and V Austenitic stainless steel has a high hot deformation resistance, even if it does not contain alloying components, so it cannot be formed into a specified shape unless it is heated to a temperature of 1000°C or higher.
Heating at a temperature exceeding "C" leads to coarsening of one grain at the initial stage of rolling, and the effect of grain refining utilizing recrystallization due to rolling is reduced.
粗圧延（ｂ）は、鋳造組織を解消するのが主目的である
から、５０％以上の加工率とするのが望ましい。Since the main purpose of rough rolling (b) is to eliminate the cast structure, it is desirable that the processing rate be 50% or more.
この粗圧延の下限温度には特に制約はないが、ξ小負荷
の点から６００℃程度の温度までにするのが好ましい。Although there is no particular restriction on the lower limit temperature of this rough rolling, it is preferable to keep the temperature up to about 600° C. in view of a small load.
粗圧延の後は、１０００−１２５０″Ｃの温度域に再加
熱する（Ｃ）、この温度域を選ぶ理由は前記の粗圧延前
の加熱温度の選定理由と同じである。After rough rolling, it is reheated to a temperature range of 1000-1250''C (C). The reason for selecting this temperature range is the same as the reason for selecting the heating temperature before rough rolling.
再加熱した後、仕上圧延を行って所定製品形状の形鋼と
する（ｄ）、このとき仕上温度（仕上圧延の終了温度）
を８５０℃以上とすることが重要である。After reheating, finishing rolling is performed to form a section steel into a predetermined product shape (d), at this time finishing temperature (finishing temperature of finishing rolling)
It is important that the temperature is 850°C or higher.
本発明方法は、圧延による再結晶を活用することによる
７粒の細粒化をはかり、強度の向上を狙うものである。The method of the present invention aims to improve strength by reducing the size of seven grains by utilizing recrystallization by rolling.
このようなオーステナイト系ステンレス鋼の再結晶温度
域は、炭素鋼に比較し高温側に存在するが、その加工量
と加工における歪速度に依存して変化する。しかし、形
鋼の圧延プロセスの加工条件においては、その再結晶の
出現する温度域は７５０″Ｃ以上である。一方、再結晶
により細粒化がはかられて強度が上昇しても、粒界に炭
化物が生じてＣｒの欠乏層に起因する耐食性の低下を招
いては意味がない、圧延後の冷却過程では炭化物の析出
は一般に促進されるが、本発明の対象とするオーステナ
イト系ステンレス鋼においては８５０℃付近が析出ノー
ズとなるため、この温度より低い温度で仕上げ圧延を行
うと炭化物の生成を回避することはできない０以上の理
由で、圧延による再結晶が期待でき、かつ圧延中少なく
とも炭化物を生じさせないために、８５０″Ｃ以上の温
度域で仕上圧延を行う必要がある。ただし、仕上圧延の
温度が１０００℃を超えると結晶粒の成長が甚だしくな
るので、上限を１０００℃までとする。The recrystallization temperature range of such austenitic stainless steel exists on the high temperature side compared to carbon steel, but it changes depending on the amount of processing and the strain rate during processing. However, under the processing conditions of the rolling process for section steel, the temperature range in which recrystallization occurs is 750"C or higher. On the other hand, even if recrystallization makes grains finer and increases strength, There is no point in causing a decrease in corrosion resistance due to a Cr-deficient layer due to the formation of carbides in the Cr-depleted layer. Although carbide precipitation is generally promoted in the cooling process after rolling, the austenitic stainless steel that is the subject of the present invention Since the precipitation nose is around 850°C, if finish rolling is performed at a temperature lower than this temperature, the formation of carbides cannot be avoided. In order to prevent the formation of carbides, it is necessary to perform finish rolling at a temperature of 850''C or higher. However, if the finishing rolling temperature exceeds 1000°C, the growth of crystal grains becomes severe, so the upper limit is set to 1000°C.
仕上圧延の後は、炭化物の析出を抑えるために空冷する
（ｅ）、空冷よりも早い条件で冷却すると、加工された
γ粒の再結晶が遅れるため加工組織が残ることがあり、
機械的性質の等方性が損なわれる。一方、炉冷のような
遅い冷却では再結晶はよく進行°するが、粒界での炭化
物析出によるＣｒ欠乏層の形成が著しく、耐食性に問題
が生じる。After finish rolling, air cooling is performed to suppress the precipitation of carbides (e). If cooling is performed faster than air cooling, the recrystallization of processed γ grains may be delayed and a processed structure may remain.
Isotropy of mechanical properties is impaired. On the other hand, in slow cooling such as furnace cooling, recrystallization progresses well, but the formation of a Cr-depleted layer due to carbide precipitation at grain boundaries is significant, causing problems in corrosion resistance.
第２図は、圧延の後に再加熱して等温保持する本発明の
もう一つのヒートパターンである。FIG. 2 shows another heat pattern of the present invention in which the material is reheated and maintained at an isothermal temperature after rolling.
圧延の前の加熱（ａ）の温度は、前記と同じ理由で１０
００〜１２５０℃とする。The temperature of heating (a) before rolling is 10% for the same reason as above.
00 to 1250°C.
この場合は、圧延（ｆ）は粗圧延から仕上圧延まで一回
の加熱で（再加熱を行うことなく）行う。In this case, rolling (f) is performed from rough rolling to finish rolling by heating once (without reheating).
圧延仕上温度は９００℃以下とする。The rolling finishing temperature shall be 900°C or less.
第２図の方法は、圧延により導入された加工歪を利用し
、再結晶の生じる温度域に短時間加熱し、再結晶を促進
するのが特徴である。そのためには、９００ ”Ｃ以下
のオーステナイトの未再結晶域で熱間加工する必要があ
る。仕上温度が低い程蓄積エネルギーが大きくなるため
、再結晶に対する駆動力が大きくなりより効果的である
が、圧延機の負荷も大きくなるからこれらを勘案して仕
上温度を決定する必要がある。実操業上、適正な仕上温
度は６００〜９００”Ｃであり、最も効果的なのは８０
０℃前後で仕上げることである。The method shown in FIG. 2 is characterized in that it utilizes processing strain introduced by rolling and heats for a short time to a temperature range where recrystallization occurs to promote recrystallization. To achieve this, it is necessary to perform hot working in the unrecrystallized region of austenite below 900 ''C.The lower the finishing temperature, the greater the stored energy, which increases the driving force for recrystallization and is more effective. , the load on the rolling mill will also increase, so it is necessary to take these into consideration when determining the finishing temperature.In actual operation, the appropriate finishing temperature is 600 to 900"C, and the most effective is 80"C.
It should be finished at around 0°C.
圧延終了後は直ちに９００〜１１００℃の温度に加熱し
て１〜６０分の間等温保持する（８）。Immediately after the rolling is completed, it is heated to a temperature of 900 to 1100°C and maintained at an isothermal temperature for 1 to 60 minutes (8).
圧延後の等温保持の目的は、等温保持することにより静
的再結晶を生じさせて７粒の細粒化をはかることにある
。この静的再結晶を生じさせるためには９００″Ｃ以上
の温度に保持する必要があり、かつその温度で少なくと
も１分以上保持する必要がある。保持時間が長いほど再
結晶は進むが、６０分までの保持で必要程度の再結晶が
得られ、これ以上の保持は生産性の低下と無用の粒生長
を招くことになるから、保持時間は１〜６０分が適当で
ある。また、１１００℃を超える温度での保持は、無用
の粒成長を招くので好ましくない、なお、等温保持とい
うのは、必ずしも厳格に一定温度で保持することを意味
しない、上記の温度範囲内であれば、ある程度の温度の
変動があっても差し支えはない。The purpose of isothermal holding after rolling is to cause static recrystallization and refine the seven grains. In order to cause this static recrystallization, it is necessary to hold the temperature at 900"C or higher, and it is necessary to hold it at that temperature for at least 1 minute.The longer the holding time, the more recrystallization progresses. A holding time of 1 to 60 minutes is appropriate because the required degree of recrystallization can be obtained by holding for up to 1,100 minutes, and holding for longer than this will result in decreased productivity and unnecessary grain growth. Holding at temperatures exceeding ℃ is undesirable as it causes unnecessary grain growth. Note that isothermal holding does not necessarily mean holding at a strictly constant temperature; as long as the temperature is within the above temperature range, There is no problem even if the temperature fluctuates.
上記の等温保持の後は、空冷以上の冷却速度で冷却する
。空冷よりも遅い速度では炭化吻生成による耐食性の劣
化が起こるのは、先に述べたとおりである。ただし、こ
の第２図の方法の場合は、等温保持の間に再結晶がほぼ
完了するため、その後の冷却速度が空冷以上に早くても
機械的性質の等方性を損なうような懸念はない。After the above isothermal maintenance, cooling is performed at a cooling rate higher than air cooling. As mentioned above, at a speed slower than air cooling, corrosion resistance deteriorates due to carbonization formation. However, in the case of the method shown in Figure 2, since recrystallization is almost completed during isothermal holding, there is no concern that the isotropy of mechanical properties will be impaired even if the subsequent cooling rate is faster than air cooling. .
（実施例）
第１表に示す組成のオーステナイトステンレス鋼を用い
てＨ形鋼を製造した。第１表中の鋼種Ａ〜Ｈが本発明で
定める組成範囲の鋼であり、比較鋼の■〜Ｌは窒素（Ｎ
）含有量が、Ｍは炭素（Ｃ）含有量、Ｎは炭素と窒素の
含有量が、それぞれ本発明の範囲から外れるものである
。(Example) H-section steel was manufactured using austenitic stainless steel having the composition shown in Table 1. Steel types A to H in Table 1 are steels within the composition range defined by the present invention, and comparative steels ■ to L are nitrogen (N
) content, M is the carbon (C) content, and N is the content of carbon and nitrogen, each of which is out of the scope of the present invention.
第２表に製造条件を示す、試験番号の１〜８が本発明方
法の例で、その中２〜４が第２図のヒートパターンの１
回の加熱で仕上圧延まで行ったものである。比較例の９
〜１８は、素材の＆ＩＩ戒または製造条件が本発明の範
囲をはずれる例である。The manufacturing conditions are shown in Table 2. Test numbers 1 to 8 are examples of the method of the present invention, and 2 to 4 are examples of the heat pattern 1 in FIG.
It was heated up to finish rolling. Comparative example 9
-18 are examples in which the material requirements or manufacturing conditions are outside the scope of the present invention.
第２表中の粗圧延の形状と仕上圧延の形状を第３図およ
び第４図に示す、これらの図中の記号（イ、口、ハ、二
）が第２表の同じ記号に対応する。The shapes of rough rolling and finish rolling in Table 2 are shown in Figures 3 and 4. The symbols (A, 口, C, 2) in these figures correspond to the same symbols in Table 2. .
第３表は、第２表の条件で製造されたＨ形鋼の機械的性
質と耐食性試験結果を示したものである機械的性質は、
母材の０．１％耐力、引張強度（ＴＳ）、降伏比（ＹＲ
＝（０，１χ耐力／引張強度）ｘｌｏｏ ） 、伸び（
ＥＬ）、および曲げ試験で評価した。 ＋ｌｈげ試験は
ＴＩＧ溶接をした継手部の１８０度曲げによって評価し
た。○印は１８０度曲げでも割れを生じなかったもの、
×印は１８０度曲げで熱影響部に割れを生じたものを示
す。Table 3 shows the mechanical properties and corrosion resistance test results of H-section steel manufactured under the conditions in Table 2.The mechanical properties are as follows:
0.1% proof stress, tensile strength (TS), yield ratio (YR) of base material
= (0,1χ proof stress/tensile strength) xloo), elongation (
EL) and a bending test. The +lh bending test was evaluated by 180 degree bending of a TIG welded joint. ○ marks are those that did not crack even when bent 180 degrees,
The mark x indicates that a crack occurred in the heat-affected zone due to 180 degree bending.
耐食性は下記■および■の試験によって評価した。Corrosion resistance was evaluated by the following tests (1) and (2).
■ 粒界腐食評価試験（硫酸−硫酸銅腐食試験、ＪＩＳ
Ｇ ０５７５．７２時間）
■ 隙間腐食試験（中央にボルト締め用の４ｍｍφの孔
を有する３ ｔＸ３０ｗＸ５０１ （ｍｓ）の研磨試験
片を３＋ｕ＋φのテフロンボルトで締めて、６０℃１８
００ｐｐｍＣ１−含有水環境でｌＯ日試Ｉｖ）
ここで耐食性の評価は、母材部と被覆アーク溶接を行っ
た継手部の双方について行った。■ Intergranular corrosion evaluation test (sulfuric acid-copper sulfate corrosion test, JIS
G 0575.72 hours) ■ Crevice corrosion test (3tX30wX501 (ms) polished specimen with a 4mmφ hole for bolt tightening in the center was tightened with 3+U+φ Teflon bolts at 60℃18
00 ppm C1-containing water environment (10 day test IV) Here, the corrosion resistance was evaluated for both the base metal part and the joint part subjected to shielded arc welding.
第３表の結果をみれば、本発明の条件を満足する試験番
号の１〜８は、いずれも機械的性質が目標性能を満足し
ており、しかも母材および溶接継手部とも耐食性も充分
である。Looking at the results in Table 3, test numbers 1 to 8 that satisfy the conditions of the present invention all have mechanical properties that meet the target performance, and both the base metal and welded joints have sufficient corrosion resistance. be.
一方、ＳＯ３３０４の成分規格は満足しているが、本発
明の成分範囲からはずれ、かつ本発明の製造条件からは
ずれている試験番号９〜１４のものは、目標性能を満足
できない結果となっている。特に、７５０℃という低温
仕上げであるため圧延により得られた組織は加工歪を内
在したものとなっておりＹＲを６０％以下に抑えること
が困難となっている。On the other hand, although the SO3304 component specifications were met, test numbers 9 to 14, which were outside the composition range of the present invention and outside the manufacturing conditions of the present invention, did not satisfy the target performance. . In particular, since the finishing process is carried out at a low temperature of 750°C, the structure obtained by rolling has inherent processing strain, making it difficult to suppress YR to 60% or less.
また低温仕上げであるため圧延後の炭化物の生成を抑制
することができず、隙間腐食の発生が生じ、本来のオー
ステナイト系ステンレス鋼の耐食性を確保できていない
。Furthermore, since it is finished at a low temperature, it is not possible to suppress the formation of carbides after rolling, resulting in crevice corrosion, and the original corrosion resistance of austenitic stainless steel cannot be ensured.
試験番号１５〜１８は本発明の組成範囲にある鋼を用い
て本発明の製造方法から外れた条件で製造した例である
。仕上温度が低すぎる例（試験番号１６）あるいはそれ
を再加熱して等温保持をするにしても保持温度が低すぎ
たり （試験番号１８）、保持温度が本発明法に対応す
る温度であっても保持時間が短すぎたり （試験番号１
７）すると、機械的性質の目標値が必ずしも満足されな
い。Test numbers 15 to 18 are examples in which steels within the composition range of the present invention were used and manufactured under conditions outside the manufacturing method of the present invention. Examples where the finishing temperature is too low (Test No. 16), or even if it is reheated and held isothermally, the holding temperature is too low (Test No. 18), or the holding temperature is a temperature that corresponds to the method of the present invention. Also, the retention time was too short (Test No. 1
7) Then, the target values of mechanical properties are not necessarily satisfied.
曲げ試験では、フェライトあるいはマルテンサイ＋−ｔ
が１２％（体積％）になった試験番号９のみが割れを呈
した。これは、窒素（Ｎ）の含有量が低く、Ｎｉ当量（
Ｎｉｅｑ）の小さい鋼（第１表の■鋼）を用いたからで
ある。In the bending test, ferrite or martensitic +-t
Only test number 9, in which the ratio was 12% (volume %), exhibited cracking. This has a low nitrogen (N) content and a Ni equivalent (
This is because a small steel (steel ■ in Table 1) was used.
（以下、余白）
（発明の効果）
以上詳述したように、本発明のオーステナイト系ステン
レス形鋼は、建築構造部材として実用化するに十分な機
械的性質と耐食性とを備えている。(Hereinafter, blank spaces) (Effects of the Invention) As detailed above, the austenitic stainless steel section of the present invention has sufficient mechanical properties and corrosion resistance to be put to practical use as a building structural member.
そして、本発明の製造方法によれば、熱間圧延工程だけ
で安価に上記の形鋼が製造できる。According to the manufacturing method of the present invention, the above-mentioned section steel can be manufactured at low cost using only a hot rolling process.
本発明は、オーステナイト系ステンレス鋼の圧延形鋼の
普及に大きく寄与する発明である。The present invention is an invention that greatly contributes to the spread of austenitic stainless steel rolled sections.
第１図および第２図は、本発明の形鋼製造方法のヒート
パターン図である。
第３図および第４図は、実施例におけるＨＪＩ鋼製造の
際の粗圧延形状と仕上圧延形状を示す図である。FIG. 1 and FIG. 2 are heat pattern diagrams of the method for manufacturing a section steel of the present invention. FIG. 3 and FIG. 4 are diagrams showing the rough rolled shape and finish rolled shape during production of HJI steel in the example.
Claims (4)
％以下、Ｍｎ：０．３０〜２．００％、Ｐ：０．０４０
％以下、Ｓ：０．０３％以下、Ｃｒ：１７〜２０％、Ｎ
ｉ：７．０〜１０．５％、Ｎ：０．０６〜０．１４％を
含有し残部Ｆｅおよび不可避的不純物からなり、残留フ
ェライトまたはマルテンサイトの量が１０％以下で、０
．１％耐力が２４Ｋｇｆ／ｍｍ＾２以上であることを特
徴とする建築構造部材用オーステナイト系ステンレス形
鋼。(1) In weight%, C: 0.03% or less, Si: 1.00
% or less, Mn: 0.30-2.00%, P: 0.040
% or less, S: 0.03% or less, Cr: 17-20%, N
i: 7.0 to 10.5%, N: 0.06 to 0.14%, the balance consists of Fe and unavoidable impurities, the amount of residual ferrite or martensite is 10% or less, and 0.
．． An austenitic stainless steel shaped steel for building structural members, characterized by a 1% yield strength of 24 Kgf/mm^2 or more.
％以下、Ｍｎ：０．３０〜２．００％、Ｐ：０．０４０
％以下、Ｓ：０．０３％以下、Ｃｒ：１７〜２０％、Ｎ
ｉ：７．０〜１０．５％、Ｎ：０．０６〜０．１４％と
、さらに、Ｍｏ：０．０５〜０．７０％、Ｎｂ：０．０
０５〜０．０８０％、Ｖ：０．００５〜０．１５％、Ｃ
ｕ：０．１０〜０．５０％、およびＴｉ：０．００５〜
０．６０％、のうちの１種以上を含有し残部Ｆｅおよび
不可避的不純物からなり、残留フェライトまたはマルテ
ンサイトの量が１０％以下で、０．１％耐力が２４Ｋｇ
ｆ／ｍｍ＾２以上であることを特徴とする建築構造部材
用オーステナイト系ステンレス形鋼。(2) In weight%, C: 0.03% or less, Si: 1.00
% or less, Mn: 0.30-2.00%, P: 0.040
% or less, S: 0.03% or less, Cr: 17-20%, N
i: 7.0-10.5%, N: 0.06-0.14%, further Mo: 0.05-0.70%, Nb: 0.0
05-0.080%, V: 0.005-0.15%, C
u: 0.10~0.50%, and Ti: 0.005~
0.60%, the remainder consists of Fe and unavoidable impurities, the amount of residual ferrite or martensite is 10% or less, and the 0.1% yield strength is 24 kg
An austenitic stainless steel section for use in architectural structural members, characterized in that it has a f/mm^2 or more.
１０００〜１２５０℃の温度域で加熱して粗圧延を施し
た後、再度１０００〜１２５０℃の温度に加熱して熱間
加工を施し、８５０〜１０００℃の温度域で所定の形状
の形鋼に成形した後空冷することを特徴とする請求項（
１）または（２）の建築構造部材用オーステナイト系ス
テンレス形鋼の製造方法。(3) After heating the steel having the composition according to claim (1) or (2) in a temperature range of 1000 to 1250°C and rough rolling, the steel is heated again to a temperature of 1000 to 1250°C and hot-rolled. A claim characterized in that the steel is processed and formed into a section steel of a predetermined shape in a temperature range of 850 to 1000°C, and then air-cooled.
1) or (2) a method for manufacturing an austenitic stainless steel section for building structural members.
１０００〜１２５０℃の温度域で加熱し、仕上温度が９
００℃以下になる条件で熱間加工を施して所定の形状の
形鋼に成形し、直ちに９００〜１１００℃の温度で１〜
６０分の間等温保持して空冷以上の冷却速度で冷却する
ことを特徴とする請求項（１）または（２）の建築構造
部材用オーステナイト系ステンレス形鋼の製造方法。(4) Steel having the composition described in claim (1) or (2) is heated in a temperature range of 1000 to 1250°C to a finishing temperature of 9.
Hot working is carried out under conditions of 00℃ or below to form a section steel into a predetermined shape.
The method for manufacturing an austenitic stainless steel section for building structural members according to claim 1 or 2, characterized in that the temperature is maintained for 60 minutes and the cooling is performed at a cooling rate higher than air cooling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1180073A JPH0611902B2 (en) | 1989-07-12 | 1989-07-12 | Stainless steel section and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1180073A JPH0611902B2 (en) | 1989-07-12 | 1989-07-12 | Stainless steel section and its manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0344449A true JPH0344449A (en) | 1991-02-26 |
| JPH0611902B2 JPH0611902B2 (en) | 1994-02-16 |
Family
ID=16076988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1180073A Expired - Fee Related JPH0611902B2 (en) | 1989-07-12 | 1989-07-12 | Stainless steel section and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0611902B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1152065A2 (en) * | 2000-05-02 | 2001-11-07 | Klaus-Peter Dr. Erkel | Process for producing high strength austenitic stainless steel |
| JP2007197821A (en) * | 2005-12-26 | 2007-08-09 | Sumitomo Metal Ind Ltd | Austenitic stainless steel |
| CN110684927A (en) * | 2019-11-08 | 2020-01-14 | 宝鸡文理学院 | Austenite type 700MPa single-phase stainless steel twisted steel and production method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60208459A (en) * | 1984-03-30 | 1985-10-21 | Aichi Steel Works Ltd | High strength stainless steel and its manufacture |
| JPS61270356A (en) * | 1985-05-24 | 1986-11-29 | Kobe Steel Ltd | Austenitic stainless steels plate having high strength and high toughness at very low temperature |
| JPS63199851A (en) * | 1986-08-30 | 1988-08-18 | Aichi Steel Works Ltd | Stainless steel having excellent corrosion fatigue resistance and seawater corrosion resistance and its production |
| JPH01132717A (en) * | 1987-11-17 | 1989-05-25 | Kawasaki Steel Corp | Production of high-strength austenitic stainless seamless steel pipe |
-
1989
- 1989-07-12 JP JP1180073A patent/JPH0611902B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60208459A (en) * | 1984-03-30 | 1985-10-21 | Aichi Steel Works Ltd | High strength stainless steel and its manufacture |
| JPS61270356A (en) * | 1985-05-24 | 1986-11-29 | Kobe Steel Ltd | Austenitic stainless steels plate having high strength and high toughness at very low temperature |
| JPS63199851A (en) * | 1986-08-30 | 1988-08-18 | Aichi Steel Works Ltd | Stainless steel having excellent corrosion fatigue resistance and seawater corrosion resistance and its production |
| JPH01132717A (en) * | 1987-11-17 | 1989-05-25 | Kawasaki Steel Corp | Production of high-strength austenitic stainless seamless steel pipe |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1152065A2 (en) * | 2000-05-02 | 2001-11-07 | Klaus-Peter Dr. Erkel | Process for producing high strength austenitic stainless steel |
| EP1152065A3 (en) * | 2000-05-02 | 2004-01-02 | Klaus-Peter Dr. Erkel | Process for producing high strength austenitic stainless steel |
| JP2007197821A (en) * | 2005-12-26 | 2007-08-09 | Sumitomo Metal Ind Ltd | Austenitic stainless steel |
| CN110684927A (en) * | 2019-11-08 | 2020-01-14 | 宝鸡文理学院 | Austenite type 700MPa single-phase stainless steel twisted steel and production method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0611902B2 (en) | 1994-02-16 |
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