JP7447377B2 - Manufacturing method of Ti-free maraging steel - Google Patents
Manufacturing method of Ti-free maraging steel Download PDFInfo
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- 229910001240 Maraging steel Inorganic materials 0.000 title claims description 59
- 238000004519 manufacturing process Methods 0.000 title claims description 23
- 238000002844 melting Methods 0.000 claims description 16
- 230000008018 melting Effects 0.000 claims description 16
- 229910052717 sulfur Inorganic materials 0.000 claims description 12
- 239000012535 impurity Substances 0.000 claims description 10
- 229910052804 chromium Inorganic materials 0.000 claims description 8
- 238000010309 melting process Methods 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 description 19
- 239000010959 steel Substances 0.000 description 19
- 229910052751 metal Inorganic materials 0.000 description 15
- 239000002184 metal Substances 0.000 description 15
- 239000011651 chromium Substances 0.000 description 14
- 238000000034 method Methods 0.000 description 12
- 239000000203 mixture Substances 0.000 description 12
- 238000005121 nitriding Methods 0.000 description 11
- 230000005540 biological transmission Effects 0.000 description 10
- 230000007423 decrease Effects 0.000 description 10
- 229910045601 alloy Inorganic materials 0.000 description 9
- 239000000956 alloy Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 230000032683 aging Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 229910000734 martensite Inorganic materials 0.000 description 6
- 229910052750 molybdenum Inorganic materials 0.000 description 6
- 238000005728 strengthening Methods 0.000 description 6
- 238000009864 tensile test Methods 0.000 description 6
- 238000010313 vacuum arc remelting Methods 0.000 description 6
- 229910000765 intermetallic Inorganic materials 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 229910001566 austenite Inorganic materials 0.000 description 4
- 150000004767 nitrides Chemical class 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 230000035882 stress Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910000943 NiAl Inorganic materials 0.000 description 1
- NPXOKRUENSOPAO-UHFFFAOYSA-N Raney nickel Chemical compound [Al].[Ni] NPXOKRUENSOPAO-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- -1 carbon) forms carbides Chemical class 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
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Description
本発明は、Ｔｉフリーマルエージング鋼の製造方法に関するものである。 The present invention relates to a method for producing Ti-free maraging steel.
マルエージング鋼は、２０００ＭＰａ前後の非常に高い引張強さをもつため、例えば、０．５ｍｍ以下の鋼帯に加工され、高強度が要求される自動車用無段変速機の金属無端ベルト等に使用されている。その代表的な組成には、質量％で１８％Ｎｉ－８％Ｃｏ－５％Ｍｏ－０．４５％Ｔｉ－０．１％Ａｌ－ｂａｌ．Ｆｅがある。しかし、上記のマルエージング鋼は、非常に高い引張強度が得られる一方、疲労強度に関しては必ずしも高くない。
マルエージング鋼の疲労強度を劣化させる最大の要因に非金属のＴｉＮ介在物が挙げられる。このＴｉＮ介在物は、その寸法が大きくなり易いうえに、形状も立方体であることから介在物を起点とした疲労破壊が生じ易くなる。そのため、Ｔｉを添加しないマルエージング鋼（以下、Ｔｉフリーマルエージング鋼と記す）が提案されている。窒化処理される金属無端ベルト用のマルエージング鋼に含まれるＴｉは、合金の基地（マトリックス）の強度を向上させるだけでなく、窒化層の強度を高める重要元素である。このＴｉを添加しないとすると基地と窒化層の両方の強度が低下することになる。そのためＴｉフリーマルエージング鋼においては、Ｔｉに代わる元素を用いて基地と窒化層とを強化する必要がある。
Maraging steel has a very high tensile strength of around 2000 MPa, so it is processed into steel strips of 0.5 mm or less and used for metal endless belts in continuously variable transmissions for automobiles that require high strength. has been done. Its typical composition includes, in mass percent, 18%Ni-8%Co-5%Mo-0.45%Ti-0.1%Al-bal. There is Fe. However, while the maraging steel described above has very high tensile strength, it does not necessarily have high fatigue strength.
Nonmetallic TiN inclusions are the biggest factor in deteriorating the fatigue strength of maraging steel. These TiN inclusions tend to be large in size and have a cubic shape, so that fatigue failure is likely to occur starting from the inclusions. Therefore, maraging steel without the addition of Ti (hereinafter referred to as Ti-free maraging steel) has been proposed. Ti contained in maraging steel for metal endless belts to be nitrided is an important element that not only improves the strength of the alloy base (matrix) but also the strength of the nitrided layer. If this Ti is not added, the strength of both the base and the nitrided layer will decrease. Therefore, in Ti-free maraging steel, it is necessary to strengthen the matrix and nitrided layer using an element that replaces Ti.
基地と窒化層とを強化する方法としては、基地の強化に寄与するＣｏの含有量を高めたうえで、窒化層の強化にＣｒやＡｌを用いる方法があり、従来から本発明者は、適量のＣｒを含有し、窒化処理時にＣｒ系やＡｌ系の窒化物を形成するＴｉフリーマルエージング鋼を鋭意検討してきた。この方法は、例えば、本願出願人の出願に係る特許文献１～特許文献６に開示されている。
特許文献１は、Ｔｉフリーマルエージング鋼で問題となる製造安定性について、Ｃｒ、Ｍｏ、Ｃｏ、Ａｌの添加量を適正範囲に管理することで安定した機械的特性が得られることを示している。特許文献２は、自動車用無段変速機の部材として使用される金属無端ベルトのマルエージング鋼において、Ｔｉフリーマルエージング鋼においても時効処理後及びガス軟窒化後に高い引張強さと内部硬さが得られることを示している。特許文献３や特許文献５、特許文献６は、疲労強度向上に有害な介在物ＴｉＮ低減のためにＴｉ、Ｎを共に低く抑え、Ｔｉ低下による強度低下をＣｏ、Ｍｏ、Ａｌ量のみの増加とＣｏ／３＋Ｍｏ＋４Ａｌの値を適正範囲に限定するとともにＢ添加することで結晶粒の調整を行い、また、Ｃｒ、Ａｌを適量添加することによって窒化による表面圧縮残留応力の絶対値を増加させることができることを示している。特許文献４は、Ｔｉ添加量の低減による強度低下をＣｏ、Ｍｏ、Ａｌの適正添加で補うとともに、Ｔｉ低下にともなう窒化性の低下をＣｒ添加で補い、さらにはマルエージング鋼の合金成分に最適な窒化処理を行なうことによって、従来のＴｉを含有するマルエージング鋼と同等以上の高疲労強度を有するマルエージング鋼帯の製造が可能であることを示している。これらの特許文献においては、Ｍｇは０．００５％以下の範囲で微量に添加される場合や、不純物として許容されている。
As a method for strengthening the base and the nitrided layer, there is a method of increasing the content of Co, which contributes to strengthening the base, and then using Cr or Al to strengthen the nitride layer. Ti-free maraging steel, which contains Cr and forms Cr-based or Al-based nitrides during nitriding, has been extensively studied. This method is disclosed, for example, in Patent Documents 1 to 6 filed by the applicant of the present invention.
Regarding manufacturing stability, which is a problem with Ti-free maraging steel, Patent Document 1 shows that stable mechanical properties can be obtained by controlling the amounts of Cr, Mo, Co, and Al added within appropriate ranges. . Patent Document 2 discloses that, in maraging steel for metal endless belts used as components of continuously variable transmissions for automobiles, high tensile strength and internal hardness can be obtained even in Ti-free maraging steel after aging treatment and gas nitrocarburizing. This indicates that the Patent Document 3, Patent Document 5, and Patent Document 6 suppress both Ti and N to a low level in order to reduce TiN inclusions that are harmful to improving fatigue strength, and reduce the strength reduction due to the decrease in Ti by increasing only the amounts of Co, Mo, and Al. It is possible to adjust the crystal grains by limiting the value of Co/3+Mo+4Al to an appropriate range and adding B, and to increase the absolute value of surface compressive residual stress due to nitridation by adding appropriate amounts of Cr and Al. It shows. Patent Document 4 compensates for the decrease in strength due to a reduction in the amount of Ti added by appropriately adding Co, Mo, and Al, and also compensates for the decrease in nitridability due to the decrease in Ti by adding Cr, and is also optimal for the alloy components of maraging steel. This shows that by performing a nitriding treatment, it is possible to manufacture a maraging steel strip having a high fatigue strength equal to or higher than that of conventional maraging steel containing Ti. In these patent documents, Mg is allowed to be added in a trace amount of 0.005% or less or as an impurity.
上述した特許文献１～特許文献６で示したマルエージング鋼は、Ｔｉフリーマルエージング鋼においても優れた熱処理特性，窒化特性、機械的特性が得られる点では有利であるものの、開示された成分範囲において、熱間延性が低下する問題があった。従来のＴｉを含有するマルエージング鋼において、Ｔｉは、強度や窒化特性を得るために必要な元素であると同時に、不純物元素のＳをＴｉ系の硫化物として固定し、Ｓの粒界偏析による熱間加工性が低下するのを抑制する効果があるため、Ｔｉフリーマルエージング鋼は製造する上で問題となる。
本発明の目的は、金属無端ベルトにも適用可能な、Ｔｉフリーマルエージング鋼の合金組成に起因する強度水準を合金組成の適正化により高めるとともに、熱間加工性さらには製造性に優れるＴｉフリーマルエージング鋼の製造方法を提供することである。
The maraging steels shown in Patent Documents 1 to 6 mentioned above are advantageous in that excellent heat treatment properties, nitriding properties, and mechanical properties can be obtained even in Ti-free maraging steels, but the disclosed composition range is However, there was a problem that hot ductility decreased. In conventional maraging steel containing Ti, Ti is an element necessary to obtain strength and nitriding properties, and at the same time, it fixes the impurity element S as Ti-based sulfide, resulting in a reduction in grain boundary segregation of S. Since it has the effect of suppressing a decrease in hot workability, Ti-free maraging steel poses a problem in manufacturing.
The purpose of the present invention is to improve the strength level of Ti-free maraging steel due to the alloy composition, which can be applied to endless metal belts, by optimizing the alloy composition, and to provide a Ti-free maraging steel with excellent hot workability and manufacturability. An object of the present invention is to provide a method for manufacturing maraging steel.
本発明者は、合金成分に起因した強度水準の大きな変化に対し、Ｃｒ、Ｍｏ、Ｃｏ、Ａｌの添加量を適正範囲に管理しつつ、不純物元素で熱間加工性を阻害するＳを固定するＭｇを適正範囲で添加してＳ／Ｍｇを制御することで安定した機械的特性と熱間加工性が得られることを見いだし本発明に到達した。
即ち本発明は、一次真空溶解において、質量％で、Ｃ：０．０１％以下、Ｎｉ：１８．０～２０．０％、Ｃｒ：１．２％以下（０は含まない）、Ｍｏ：４．５～６．０％、Ｃｏ：９．０～１４．０％、Ａｌ：０．８～１．７％、Ｓ：０．００３０％以下、Ｍｇ：０．００２０～０．０１００％、残部は、Ｆｅ及び不可避的不純物でなるマルエージング鋼製消耗電極を製造する一次溶解工程と、前記消耗電極を用いて、真空再溶解を行ってマルエージング鋼製鋼塊を製造する真空再溶解工程を含むＴｉフリーマルエージング鋼の製造方法である。
好ましくは、前記消耗電極中のＳとＭｇとの関係が、Ｓ／Ｍｇで０．０２～０．２５であるＴｉフリーマルエージング鋼の製造方法である。
好ましくは、前記マルエージング鋼製鋼塊のＳとＭｇ含有量が、質量％でＳ：０．００２５％以下、Ｍｇ：０．００４０％以下（０は含まない）であるＴｉフリーマルエージング鋼の製造方法である。
The present inventor fixed S, which is an impurity element and inhibits hot workability, while controlling the addition amounts of Cr, Mo, Co, and Al within appropriate ranges in response to large changes in strength levels caused by alloy components. The present invention was achieved by discovering that stable mechanical properties and hot workability can be obtained by adding Mg in an appropriate range and controlling S/Mg.
That is, in the present invention, in the primary vacuum melting, in mass %, C: 0.01% or less, Ni: 18.0 to 20.0%, Cr: 1.2% or less (not including 0), Mo: 4 .5 to 6.0%, Co: 9.0 to 14.0%, Al: 0.8 to 1.7%, S: 0.0030% or less, Mg: 0.0020 to 0.0100%, balance The method includes a primary melting process of producing a maraging steel consumable electrode made of Fe and unavoidable impurities, and a vacuum remelting process of producing a maraging steel ingot by performing vacuum remelting using the consumable electrode. This is a method for producing Ti-free maraging steel.
Preferably, the method for producing Ti-free maraging steel is such that the relationship between S and Mg in the consumable electrode is 0.02 to 0.25 in terms of S/Mg.
Preferably, the S and Mg contents of the maraging steel ingot are S: 0.0025% or less and Mg: 0.0040% or less (0 is not included) in mass %. It's a method.
本発明のＴｉフリーマルエージング鋼は合金組成に起因する強度水準を適正化することで優れた機械的特性を有しており、さらにはＴｉフリーのマルエージング鋼の問題点であった熱間加工性を改善することで優れた製造性も有することから自動車用無段変速機の金属無端ベルトのように強度と製造性が要求される部材に使用されると安定した機械的特性が得られるなど、工業的な効果を持つことが期待される。 The Ti-free maraging steel of the present invention has excellent mechanical properties by optimizing the strength level due to the alloy composition, and it also has excellent mechanical properties that can be easily processed through hot processing, which was a problem with Ti-free maraging steel. By improving the properties, it also has excellent manufacturability, so it can provide stable mechanical properties when used in parts that require strength and manufacturability, such as endless metal belts for continuously variable automobile transmissions. , is expected to have industrial effects.
上述したように、本発明の重要な特徴は優れた機械的特性と熱間加工性を改善するために必要な合金組成を適正化及び適正範囲で添加したことにある。
本発明のＴｉフリーマルエージング鋼の製造方法において、一次溶解後の消耗電極を以下の範囲で各化学組成を規定した理由は以下の通りである。なお、特に記載のない限り質量％として記す。
＜Ｃ：０．０１％以下＞
Ｃ（炭素）は、ＭｏやＣｒと炭化物を形成して、析出すべき金属間化合物や窒化物の生成を阻害して強度を低下させるため、低く抑える必要がある。また、Ｃを積極添加すると、例えは無段変速機用部材に必要とされる溶接性が低下し、製造性が低下する。このような理由からＣは０．０１％以下とした。このましくは、０．００８％以下である。一方で、Ｃの微量添加は微細な炭化物を形成し、強度向上に寄与することから０．００１％以上が好ましい。
＜Ｎｉ：１８．０～２０．０％＞
Ｎｉは、Ｔｉフリーマルエージング鋼の基地組織である低Ｃマルテンサイト組織を安定して形成させるため、少なくとも１８．０％は必要である。しかし、２０．０％を超えるとオーステナイト組織が安定化するため、熱処理時にマルテンサイト変態を起こし難くなることから、Ｎｉは１８．０～２０．０％とした。Ｎｉの好ましい下限は１８．５％超であり、好ましい上限値は１９．５％である。
As mentioned above, an important feature of the present invention is that the alloy composition necessary for improving mechanical properties and hot workability is optimized and added within an appropriate range.
In the method for producing Ti-free maraging steel of the present invention, the chemical composition of the consumable electrode after primary melting is defined in the following ranges for the following reasons. In addition, unless otherwise specified, it is expressed as mass %.
<C: 0.01% or less>
C (carbon) forms carbides with Mo and Cr, inhibits the formation of intermetallic compounds and nitrides to be precipitated, and reduces strength, so it needs to be kept low. Furthermore, if C is actively added, the weldability required for a continuously variable transmission member, for example, decreases, and manufacturability decreases. For these reasons, C was set to 0.01% or less. Preferably, it is 0.008% or less. On the other hand, since the addition of a small amount of C forms fine carbides and contributes to improving strength, it is preferably 0.001% or more.
<Ni: 18.0-20.0%>
Ni is required to be at least 18.0% in order to stably form a low C martensitic structure, which is the base structure of Ti-free maraging steel. However, if Ni exceeds 20.0%, the austenitic structure is stabilized, making martensitic transformation less likely to occur during heat treatment, so Ni was set at 18.0 to 20.0%. A preferable lower limit of Ni is more than 18.5%, and a preferable upper limit is 19.5%.
＜Ｃｒ：１．２％以下（０は含まない）＞
Ｃｒは、窒化を行う場合にＮとの親和力が強く、窒化深さを浅くし、窒化硬さを高めたり、窒化表面の圧縮残留応力を増加させたりする元素であるため必須で添加する。１．２％を超えると窒化硬さが高くなり過ぎてしまい、例えば、Ｔｉフリーマルエージング鋼の好適な用途である金属無端ベルトの製造工程の中に形成される表面疵などの欠陥に対する感受性が高まることで疲労強度が低下したり、熱処理時のマルテンサイト変態温度が低下することでオーステナイトが残留し易くなり、硬さや強度が得られなくなることからＣｒは１．２％以下とした。Ｃｒの好ましい上限は１．０％である。
＜Ｍｏ：４．５～６．０％＞
Ｍｏは、時効処理時のＮｉ３Ｍｏ等の微細な金属間化合物を形成し、析出強化に寄与する重要な元素である。また、Ｍｏは窒化による表面の硬さ及び圧縮残留応力を大きくするために有効な元素である。このため、Ｍｏは４．５％よりも少ないと金属間化合物の析出量の低下により引張強度は不十分となり、一方、６．０％より多いとＦｅ、Ｍｏを主要元素とする粗大な金属間化合物を形成し易くなるとともに固溶化処理で形成されるオーステナイト相を固溶強化するため冷却課程でマルテンサイト変態を阻害し，オーステナイトが残留し易くなることからＭｏは４．５～６．０％とした。Ｍｏの好ましい下限は４．５％超であり、好ましい上限は５．８％である。
<Cr: 1.2% or less (0 is not included)>
When performing nitriding, Cr is an element that has a strong affinity with N, reduces the nitriding depth, increases nitriding hardness, and increases compressive residual stress on the nitrided surface, so it is essential to add. If it exceeds 1.2%, the nitriding hardness will become too high, and the susceptibility to defects such as surface scratches formed during the manufacturing process of metal endless belts, which is the preferred application for Ti-free maraging steel, will increase. The content of Cr is set to 1.2% or less because increasing the chromium content lowers the fatigue strength, lowering the martensitic transformation temperature during heat treatment and making it easier for austenite to remain, making it impossible to obtain hardness and strength. A preferable upper limit of Cr is 1.0%.
<Mo: 4.5-6.0%>
Mo is an important element that forms fine intermetallic compounds such as Ni 3 Mo during aging treatment and contributes to precipitation strengthening. Further, Mo is an effective element for increasing surface hardness and compressive residual stress due to nitriding. Therefore, if Mo is less than 4.5%, the tensile strength will be insufficient due to a decrease in the amount of precipitated intermetallic compounds, while if it is more than 6.0%, coarse intermetallic compounds containing Fe and Mo as main elements will be formed. Mo content is 4.5 to 6.0% because it becomes easier to form compounds and also strengthens the austenite phase formed by solution treatment, inhibiting martensitic transformation during the cooling process and making it easier for austenite to remain. And so. The preferable lower limit of Mo is more than 4.5%, and the preferable upper limit is 5.8%.
＜Ｃｏ：９．０～１４．０％＞
Ｃｏは、基地組織のマルテンサイト組織の安定性に大きく影響することなく固溶化処理温度で時効析出物の形成元素であるＭｏの固溶度を増加させ、時効析出温度域でのＭｏの固溶度を低下させることによってＭｏを含む微細な金属間化合物の析出を促進し、時効析出強化に寄与する重要な元素である。そのため、Ｃｏは強度面、じん性面から多く添加することが必要である。Ｃｏは９．０％未満ではＴｉフリーマルエージング鋼において十分な強度が得られにくく、一方で、１４．０％を超えて添加するとオーステナイトが安定化してマルテンサイト組織が得られ難くなることから９．０～１４．０％とした。好ましいＣｏの下限は１０．０％であり、好ましい上限は１３．５％である。
＜Ａｌ：０．８～１．７％＞
Ａｌは、通常、脱酸のために少量添加されるが、添加量が多くなると時効処理時にＮｉと共にＮｉＡｌを形成して強化に寄与する元素である。Ｔｉを無添加とした本発明のＴｉフリーマルエージング鋼ではＡｌの添加によって強度を補う必要がある。また、例えば、Ｔｉフリーマルエージング鋼の好適な用途である金属無端ベルトの製造工程において窒化処理を容易にして良好な窒化層を得るためにもＡｌの添加が必要である。Ａｌは、０．８％未満では時効処理時に十分な強化作用が得られず、一方で１．７％より多いと窒化層が硬くなりすぎてしまい疲労強度を低下させたり、表面に薄くて安定な酸化膜を形成して窒化反応を阻害したりすることから、Ａｌは０．８％～１．７％とした。好ましいＡｌの下限は０．９％であり、好ましいＡｌの上限は１．６％である。
<Co:9.0-14.0%>
Co increases the solid solubility of Mo, which is an element forming aging precipitates, at the solution treatment temperature without significantly affecting the stability of the martensitic structure of the matrix structure, and increases the solid solubility of Mo in the aging precipitation temperature range. It is an important element that promotes the precipitation of fine intermetallic compounds containing Mo by lowering the Mo content and contributes to aging precipitation strengthening. Therefore, it is necessary to add a large amount of Co from the viewpoint of strength and toughness. If Co is less than 9.0%, it is difficult to obtain sufficient strength in Ti-free maraging steel, while if it is added in excess of 14.0%, austenite is stabilized and it becomes difficult to obtain a martensitic structure.9 .0 to 14.0%. The preferable lower limit of Co is 10.0%, and the preferable upper limit is 13.5%.
<Al: 0.8-1.7%>
Al is usually added in a small amount for deoxidation, but when added in a large amount, it is an element that forms NiAl together with Ni during aging treatment and contributes to strengthening. In the Ti-free maraging steel of the present invention in which Ti is not added, it is necessary to supplement the strength by adding Al. Further, for example, addition of Al is necessary to facilitate nitriding treatment and obtain a good nitrided layer in the manufacturing process of metal endless belts, which is a preferred use of Ti-free maraging steel. If Al is less than 0.8%, a sufficient strengthening effect cannot be obtained during aging treatment, while if it is more than 1.7%, the nitrided layer becomes too hard, reducing fatigue strength, or the surface becomes thin and stable. Since Al forms an oxide film and inhibits the nitriding reaction, the content of Al was set at 0.8% to 1.7%. A preferable lower limit of Al is 0.9%, and a preferable upper limit of Al is 1.6%.
＜Ｓ：０．００３０％以下＞
Ｓは、マルエージング鋼において結晶粒界に偏析して結晶粒界を脆化させる不純物元素である。Ｓが結晶粒界に偏析すると、熱間加工時に結晶粒界の変形能が失われ、容易に粒界破壊が生じてしまい熱間加工性を大幅に低下させてしまう。そのためＳはできる限り低く抑える必要があることから０．００３０％以下とした。なお、Ｓは不可避的に混入する不純物の一つであり、溶解原料に含まれるものである。そのため、Ｓを０％とするのは困難であり、一次溶解でのＳは、０．０００２％以上は含まれ得る。
＜Ｍｇ：０．００２０～０．０１００％＞
Ｍｇは、本発明のＴｉフリーマルエージング鋼において非常に重要な元素である。従来のＴｉを含むマルエージング鋼は、結晶粒界に偏析し結晶粒界を脆化させるＳをＴｉがＴｉＳとして固定することでＳの偏析による粒界脆化を抑制する効果があった。しかし、本発明のＴｉフリーマルエージング鋼では基本組成にＳを固定する元素を含まないため、Ｔｉに変わる新たなＳを固定する元素を添加する必要がありＭｇの添加が必要である。ＭｇはＴｉと同じくＳをＭｇＳとして固定し、安定化したＭｇＳは再溶解後もＭｇＳのまま維持され、さらにはＭｇＳ自身が延性に富むことから熱間延性の改善に最適な元素である。このようなＭｇの効果を得るためにはＭｇは０．００２０％以上の添加が必要であるが０．０１００％を超えると粗大な酸化物を形成し疲労強度を低下させるためＭｇは０．００２０～０．０１００％とした。Ｍｇの好ましい下限は０．００２５％であり、好ましい上限は０．００６０％である。より好ましい上限は０．００５０％である。
<S: 0.0030% or less>
S is an impurity element that segregates at grain boundaries and embrittles the grain boundaries in maraging steel. When S segregates at grain boundaries, the deformability of the grain boundaries is lost during hot working, easily causing grain boundary fracture, and significantly reducing hot workability. Therefore, S needs to be kept as low as possible, so it is set to 0.0030% or less. Note that S is one of the impurities that are inevitably mixed in and is included in the dissolved raw material. Therefore, it is difficult to reduce S to 0%, and S in primary dissolution may contain 0.0002% or more.
<Mg: 0.0020-0.0100%>
Mg is a very important element in the Ti-free maraging steel of the present invention. Conventional maraging steel containing Ti has the effect of suppressing grain boundary embrittlement due to S segregation because Ti fixes S as TiS, which segregates at grain boundaries and embrittles the grain boundaries. However, since the Ti-free maraging steel of the present invention does not include an element that fixes S in its basic composition, it is necessary to add a new element that fixes S to replace Ti, and Mg needs to be added. Like Ti, Mg fixes S as MgS, and stabilized MgS remains as MgS even after remelting, and MgS itself is highly ductile, so it is an optimal element for improving hot ductility. In order to obtain such an effect of Mg, it is necessary to add Mg in an amount of 0.0020% or more, but if it exceeds 0.0100%, coarse oxides are formed and fatigue strength is reduced, so Mg must be added in an amount of 0.0020% or more. ~0.0100%. The preferable lower limit of Mg is 0.0025%, and the preferable upper limit is 0.0060%. A more preferable upper limit is 0.0050%.
＜消耗電極中のＳとＭｇとの関係が、Ｓ／Ｍｇで０．０２～０．２５＞
先述したようにＳは結晶粒界に偏析することで結晶粒界を脆化させる作用があるためＭｇを添加してＭｇＳとすることでＳを無害化できる。ＳとＭｇの比であるＳ／Ｍｇは本発明のＴｉフリーマルエージング鋼において、０．０２よりも小さいとＭｇが過剰添加となり、一方で０．２５よりも大きいとＳを固定するＭｇが不足するためＳ／Ｍｇは０．０２～０．２５とした。好ましいＳ／Ｍｇの下限は０．０５であり、好ましい上限は０．２０である。
＜Ｆｅ及び不可避的不純物＞
説明する元素以外は、Ｆｅおよび不可避的不純物とする。しかし、以下の元素は、以下の範囲であれば脱酸、脱硫等の目的で添加しても良い。
Ｃａ≦０．００１％、Ｚｒ≦０．０１％、Ｂ≦０．００５％
<The relationship between S and Mg in the consumable electrode is 0.02 to 0.25 in S/Mg>
As mentioned above, S has the effect of embrittling the crystal grain boundaries by segregating at the grain boundaries, so S can be rendered harmless by adding Mg to form MgS. In the Ti-free maraging steel of the present invention, when S/Mg, which is the ratio of S to Mg, is smaller than 0.02, Mg is added excessively, whereas when it is larger than 0.25, there is insufficient Mg to fix S. Therefore, S/Mg was set to 0.02 to 0.25. A preferable lower limit of S/Mg is 0.05, and a preferable upper limit is 0.20.
<Fe and inevitable impurities>
Elements other than those described are Fe and inevitable impurities. However, the following elements may be added for purposes such as deoxidation and desulfurization as long as they are within the following ranges.
Ca≦0.001%, Zr≦0.01%, B≦0.005%
＜製造工程＞
本発明のＴｉフリーマルエージング鋼の製造において、上述した化学組成の規定範囲内で製造（一次溶解）した消耗電極を用いて、真空再溶解を行ってマルエージング鋼製鋼塊を製造する真空再溶解工程を含んでいる。本発明において、一次溶解は真空溶解の適用が好ましく、なかでも真空誘導溶解（ＶＩＭ）を適用するのが好ましい。ＶＩＭを適用すれば大気中の酸素、窒素と溶鋼との反応による鋼中の酸化物、窒化物の増加を避ける点、酸素と活性なＭｇを安定して溶鋼中に添加するのに有利である点、原料から不可避的に混入する酸素、窒素を除去できる機能を有している点から消耗電極の製造に最適であるためである。また、真空再溶解工程を含むことで不純物元素の低減やさらには非金属介在物の低減、一次溶解時の不均一な鋼塊組織を改善することができる。真空再溶解としては、真空アーク再溶解（ＶＡＲ）を適用するのが好ましい。ＶＡＲを適用することとすれば、前述の効果を確実に得ることができる。
<Manufacturing process>
In the production of Ti-free maraging steel of the present invention, vacuum remelting is performed to produce a maraging steel ingot by using a consumable electrode produced within the specified range of chemical composition (primary melting) as described above. Contains processes. In the present invention, vacuum melting is preferably applied as the primary melting, and vacuum induction melting (VIM) is particularly preferred. Application of VIM is advantageous in avoiding an increase in oxides and nitrides in steel due to reactions between oxygen and nitrogen in the atmosphere and molten steel, and in stably adding oxygen and active Mg to molten steel. This is because it is ideal for manufacturing consumable electrodes because it has the ability to remove oxygen and nitrogen that are inevitably mixed in from raw materials. Furthermore, by including a vacuum remelting step, it is possible to reduce impurity elements, further reduce nonmetallic inclusions, and improve the uneven steel ingot structure during primary melting. As the vacuum remelting, vacuum arc remelting (VAR) is preferably applied. By applying VAR, the aforementioned effects can be reliably obtained.
前述の真空再溶解後においては、ＳとＭｇの含有量が変化するため、真空再溶解で得られた鋼塊のＳ及びＭｇ含有量につて説明する。
＜Ｓ：０．００２５％以下、Ｍｇ：０．００４０％以下（０は含まない）＞
本発明のＴｉフリーマルエージング鋼の製造方法において、再溶解後のＳ及びＭｇ量を以下の理由で規定した。
Ｓは先述した真空再溶解工程により未溶解のＭｇＳは溶解中の対流により鋼塊の表面にトラップされ一次溶解時よりも低減することが期待される。再溶解時のＳ量が０．００２５％以下であれば、仮にＭｇＳとして固定されていないＳが存在していても再溶解時の均一かつ微細な凝固組織により、結晶粒界等の界面の面積が一次溶解時よりも増加するため、単位面積辺りに偏析するＳ量は大幅に低減され粒界脆化が抑制される。Ｓが０．００２５％よりも多いと結晶粒界に偏析するＳ濃度が多くなり粒界脆化を引き起こす。また、Ｍｇは、Ｓを固定する元素であるが蒸気圧が大きい元素であるためＭｇＳとして固定されていないＭｇは再溶解時に蒸発してしまい必然的に一次溶解時よりも量が少なくなるため０．００４０％以下とした。なお、再溶解後の鋼塊中のＳとＭｇについては、その含有量が０％になることはなく、再溶解後もＭｇＳとして残留するものが存在するため、Ｓについては０．０００２％程度、Ｍｇについては０．０００３％程度は残留し得る。
Since the S and Mg contents change after the vacuum remelting described above, the S and Mg contents of the steel ingot obtained by the vacuum remelting will be explained.
<S: 0.0025% or less, Mg: 0.0040% or less (0 is not included)>
In the method for producing Ti-free maraging steel of the present invention, the amounts of S and Mg after remelting are specified for the following reasons.
It is expected that the undissolved MgS in the vacuum remelting process described above will be trapped on the surface of the steel ingot by convection during melting, and that the S content will be reduced compared to during the primary melting. If the amount of S at the time of remelting is 0.0025% or less, even if there is S that is not fixed as MgS, the area of interfaces such as grain boundaries will decrease due to the uniform and fine solidified structure at the time of remelting. Since the amount of S is increased compared to that during primary melting, the amount of S segregated per unit area is significantly reduced and grain boundary embrittlement is suppressed. When S is more than 0.0025%, the S concentration segregated at grain boundaries increases, causing grain boundary embrittlement. In addition, Mg is an element that fixes S, but since it has a high vapor pressure, Mg that is not fixed as MgS will evaporate during remelting, and the amount will inevitably be smaller than during the primary melting. .0040% or less. Note that the content of S and Mg in the steel ingot after remelting will never reach 0%, and some will remain as MgS even after remelting, so the S content will be around 0.0002%. , about 0.0003% of Mg may remain.
以上に説明する本発明のＴｉフリーマルエージング鋼の製造方法を適用することで、合金組成に起因する強度や硬さ水準を適正化でき、さらには熱間加工性に優れるマルエージング鋼を得ることが可能となり、優れた機械的特性と製造性を両立することができる。
本発明のＴｉフリーマルエージング鋼の製造方法で得られたＴｉフリーマルエージング鋼鋼塊を自動車用無段変速機の金属無端ベルトに適用するには、再溶解で得られた鋼塊に熱間鍛造、熱間圧延等の熱間加工を繰返す工程を含み、冷間圧延と焼鈍とを繰返して０．５ｍｍ以下の鋼帯とすれば、その金属無端ベルト用鋼は、引張強さや疲労強度に代表される機械的特性を向上させた自動車用無段変速機の金属無端ベルトとすることが可能である。そのため、自動車用無段変速機の金属無端ベルト用鋼の製造方法として最適である。
By applying the method for producing Ti-free maraging steel of the present invention described above, it is possible to optimize the strength and hardness level due to the alloy composition, and further to obtain maraging steel with excellent hot workability. This makes it possible to achieve both excellent mechanical properties and manufacturability.
In order to apply the Ti-free maraging steel ingot obtained by the method for producing Ti-free maraging steel of the present invention to a metal endless belt of a continuously variable transmission for automobiles, the steel ingot obtained by remelting is heated. If a steel strip of 0.5 mm or less is produced by repeating hot working processes such as forging and hot rolling, and by repeating cold rolling and annealing, the steel for endless metal belts will have poor tensile strength and fatigue strength. It is possible to make a metal endless belt for a continuously variable transmission for an automobile with improved typical mechanical properties. Therefore, it is most suitable as a method for manufacturing steel for metal endless belts of continuously variable transmissions for automobiles.
以下の実施例で本発明をさらに詳しく説明する。
Ｔｉフリーマルエージング鋼を真空溶解炉（ＶＩＭ）で消耗電極を溶製し、続く真空アーク再溶解（ＶＡＲ）にて１２，０００ｋｇ鋼塊を作製した。その後、鋼塊に熱間鍛造を施し、断面が２１０ｍｍ×６３０ｍｍの鍛造素材を準備した。
比較例のＴｉフリーマルエージング鋼は、真空溶解炉で１０ｋｇの鋼塊を溶製し、熱間鍛造を施し、断面が２０ｍｍ×５０ｍｍの鍛造材を準備した。
本発明（Ｎｏ．１）と比較例（Ｎｏ．２）のＴｉフリーマルエージング鋼の一次溶解後の化学組成とＳとＭｇの比であるＳ／Ｍｇを表１に示す。なお、比較例のＭｇは無添加のため０ｍａｓｓ％もしくは限りなく０ｍａｓｓ％に近い値であり、Ｓ／Ｍｇは算出が出来ないがＳ／Ｍｇは０．２５よりも大きな値である。表１で１Ａとして示すのは一次溶解（ＶＩＭ）後の分析結果であり、１Ｂとして示すのは真空再溶解（ＶＡＲ）後の分析結果である。
The invention will be explained in more detail in the following examples.
A consumable electrode was melted from Ti-free maraging steel in a vacuum melting furnace (VIM), and then a 12,000 kg steel ingot was produced by vacuum arc remelting (VAR). Thereafter, the steel ingot was hot forged to prepare a forged material with a cross section of 210 mm x 630 mm.
For the Ti-free maraging steel of the comparative example, a 10 kg steel ingot was melted in a vacuum melting furnace and hot forged to prepare a forged material with a cross section of 20 mm x 50 mm.
Table 1 shows the chemical compositions of the Ti-free maraging steels of the present invention (No. 1) and comparative example (No. 2) after primary melting and the S/Mg ratio. Note that Mg in the comparative example is 0 mass% or extremely close to 0 mass% since no additives are added, and although S/Mg cannot be calculated, S/Mg is a value larger than 0.25. In Table 1, 1A is the analysis result after primary melting (VIM), and 1B is the analysis result after vacuum remelting (VAR).
それぞれの鍛造材からφ１２ｍｍ×８０ｍｍの引張用試験片を採取して、試験温度が８５０℃、９００℃、９５０℃、１０００℃、１１００℃、１２００℃で歪速度が１／ｓの高温引張試験を実施し、熱間加工性を評価した。高温引張試験結果の伸びを表２、絞りを表３、引張強さを表４に示す。
表２の高温引張試験時の伸び値を比較すると、本発明のＴｉフリーマルエージング鋼は、比較例よりも高い値であり、５０％以上の伸び値が得られる温度は、比較例が１１００℃以上であるのに対し、本発明が９００℃以上であり、優れた高温延性を有していることがわかる。
表３の高温引張試験時の絞り値を比較すると、本発明のＴｉフリーマルエージング鋼は、比較例よりも高い値であり、５０％以上の絞り値が得られる温度は、比較例が１１００℃以上であるのに対し、本発明が８５０℃以上であり、優れた高温延性を有していることがわかる。
表４の高温引張試験時の引張強さを比較すると、本発明のＴｉフリーマルエージング鋼は、高温延性が高いにも関わらず比較例と同じ強度水準であり、優れた機械的特性を有していることがわかる。
A tensile test piece of φ12 mm x 80 mm was taken from each forged material, and a high temperature tensile test was conducted at test temperatures of 850°C, 900°C, 950°C, 1000°C, 1100°C, and 1200°C with a strain rate of 1/s. The hot workability was evaluated. Table 2 shows the elongation, Table 3, and Table 4 show the elongation and tensile strength of the high temperature tensile test results.
Comparing the elongation values during the high temperature tensile test in Table 2, the Ti-free maraging steel of the present invention has a higher value than the comparative example, and the temperature at which an elongation value of 50% or more is obtained is 1100°C for the comparative example. In contrast, the temperature of the present invention is 900°C or higher, which shows that it has excellent high-temperature ductility.
Comparing the reduction of area values during the high-temperature tensile test in Table 3, the Ti-free maraging steel of the present invention has a higher value than the comparative example, and the temperature at which a reduction of area of 50% or more is obtained is 1100°C for the comparative example. In contrast, the temperature of the present invention is 850° C. or higher, which shows that it has excellent high-temperature ductility.
Comparing the tensile strength during the high temperature tensile test in Table 4, the Ti-free maraging steel of the present invention has the same strength level as the comparative example despite having high high temperature ductility, and has excellent mechanical properties. It can be seen that
以上の結果から、本発明のＴｉフリーマルエージング鋼の製造方法を適用したＴｉフリーマルエージング鋼は、強度水準を合金組成の適正化により向上させ、また、優れた高温延性を有していることから、優れた熱間加工性を有していることが分かる。そのため、熱間加工を繰り返すような自動車用無段変速機の金属無端ベルト用鋼の製造に適用すれば、製造性を高めることが可能である。
From the above results, the Ti-free maraging steel to which the Ti-free maraging steel manufacturing method of the present invention is applied has improved strength level by optimizing the alloy composition, and has excellent high-temperature ductility. It can be seen from the above that it has excellent hot workability. Therefore, if applied to the production of steel for metal endless belts of continuously variable transmissions for automobiles, which require repeated hot working, it is possible to improve productivity.
本発明のＴｉフリーマルエージング鋼の製造方法は、過酷な条件で使用される金属ベルトに用いることが可能であるため、自動車用無段変速機等に使用される動力伝達金属ベルトのような高引張強度、高疲労強度さらには優れた熱間加工、製造性が要求される部材に適用できる。
The method for producing Ti-free maraging steel of the present invention can be used for metal belts used under harsh conditions, so it can be used for high-speed metal belts such as power transmission metal belts used in continuously variable transmissions for automobiles. It can be applied to parts that require tensile strength, high fatigue strength, and excellent hot workability and manufacturability.
Claims (2)
前記消耗電極を用いて、真空再溶解を行ってマルエージング鋼製鋼塊を製造する真空再溶解工程を含み、前記消耗電極中のＳとＭｇとの関係が、Ｓ／Ｍｇで０．０２～０．２５であることを特徴とするＴｉフリーマルエージング鋼の製造方法。 In primary vacuum melting, C: 0.01% or less, Ni: 18.0 to 20.0%, Cr: 1.2% or less (not including 0), Mo: 4.5 to 6. 0%, Co: 9.0-14.0%, Al: 0.8-1.7%, S: 0.0030% or less, Mg: 0.0020-0.0100%, the remainder is Fe and unavoidable a primary melting process to produce a maraging steel consumable electrode made of impurities;
The consumable electrode includes a vacuum remelting step of performing vacuum remelting to produce a maraging steel ingot, and the relationship between S and Mg in the consumable electrode is 0.02 to 0.02 in terms of S/Mg. 0.25. A method for producing Ti-free maraging steel.
According to claim 1 , the S and Mg contents of the maraging steel ingot are S: 0.0025% or less and Mg: 0.0040% or less (not including 0) in mass %. A method for producing Ti-free maraging steel.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005248187A (en) | 2004-02-05 | 2005-09-15 | Hitachi Metals Ltd | Method for manufacturing maraging steel, and maraging steel |
| JP2008088540A (en) | 2005-12-13 | 2008-04-17 | Hitachi Metals Ltd | Maraging steel having high fatigue strength and maraging steel strip using the same |
| JP2008185183A (en) | 2007-01-31 | 2008-08-14 | Hitachi Metals Ltd | Method of manufacturing maraging steel strip having high fatigue strength |
| JP2009013464A (en) | 2007-07-04 | 2009-01-22 | Hitachi Metals Ltd | Maraging steel for metal belt |
| JP2013253277A (en) | 2012-06-06 | 2013-12-19 | Ihi Corp | Maraging steel |
| JP2016000409A (en) | 2014-06-11 | 2016-01-07 | 日立金属株式会社 | Maraging steel manufacturing method |
| JP2017043817A (en) | 2015-08-28 | 2017-03-02 | 大同特殊鋼株式会社 | METHOD FOR PRODUCING Ti-CONTAINING MARAGING STEEL AND METHOD FOR PRODUCING THE PREFORM THEREOF |
| JP2019167578A (en) | 2018-03-23 | 2019-10-03 | 日立金属株式会社 | Maraging steel for metal belt |
-
2020
- 2020-03-24 JP JP2020052265A patent/JP7447377B2/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005248187A (en) | 2004-02-05 | 2005-09-15 | Hitachi Metals Ltd | Method for manufacturing maraging steel, and maraging steel |
| JP2008088540A (en) | 2005-12-13 | 2008-04-17 | Hitachi Metals Ltd | Maraging steel having high fatigue strength and maraging steel strip using the same |
| JP2008185183A (en) | 2007-01-31 | 2008-08-14 | Hitachi Metals Ltd | Method of manufacturing maraging steel strip having high fatigue strength |
| JP2009013464A (en) | 2007-07-04 | 2009-01-22 | Hitachi Metals Ltd | Maraging steel for metal belt |
| JP2013253277A (en) | 2012-06-06 | 2013-12-19 | Ihi Corp | Maraging steel |
| JP2016000409A (en) | 2014-06-11 | 2016-01-07 | 日立金属株式会社 | Maraging steel manufacturing method |
| JP2017043817A (en) | 2015-08-28 | 2017-03-02 | 大同特殊鋼株式会社 | METHOD FOR PRODUCING Ti-CONTAINING MARAGING STEEL AND METHOD FOR PRODUCING THE PREFORM THEREOF |
| JP2019167578A (en) | 2018-03-23 | 2019-10-03 | 日立金属株式会社 | Maraging steel for metal belt |
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