JP2668113B2 - Method for producing high-strength non-magnetic stainless steel material with excellent workability - Google Patents

Method for producing high-strength non-magnetic stainless steel material with excellent workability

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Publication number
JP2668113B2
JP2668113B2 JP61182039A JP18203986A JP2668113B2 JP 2668113 B2 JP2668113 B2 JP 2668113B2 JP 61182039 A JP61182039 A JP 61182039A JP 18203986 A JP18203986 A JP 18203986A JP 2668113 B2 JP2668113 B2 JP 2668113B2
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less
steel
final annealing
workability
strength
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JPS6338558A (en
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敏彦 武本
和夫 星野
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日新製鋼株式会社
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【発明の詳細な説明】 〔産業上の利用分野〕 本発明は磁気特性を利用して機能する各種機器・装置
に使用される加工性に優れ、かつ高強度を有する非磁性
ステンレス鋼材料の製造方法に関する。 〔従来技術とその問題点〕 SUS304に代表されるCr−Ni系オーステナイトステンレ
ス鋼は良好な耐食性と加工性を有し、かつ焼鈍状態で非
磁性のオーステナイト組織を有するので、非磁性鋼とし
て電気、精密機器部品用に使用されている。また部品に
よっては強度を必要とするため冷間加工を施した後に使
用されている。しかしながら、SUS304鋼はオーステナイ
ト相が準安定であるため、冷間加工中にマルテンサイト
変態が生じ、磁性を帯びるようになる。そこでそのよう
な目的には、オーステナイト相がさらに安定なSUS316が
使用されている。 しかしながら、これらのCr−Ni系オーステナイト鋼は
本来、非磁性鋼として開発されたものでなく、汎用鋼を
単に非磁性用途に転用したものにすぎない。例えば、よ
りオーステナイト相の安定なSUS316系は高価なNi、Moを
多量に含有しているが、Moは耐食性に優れた効果を発揮
するものの高強度あるいは非磁性に対する寄与は低い。 高Si含有鋼としては、耐熱鋼や耐応力腐食割れ鋼があ
り、これらの鋼種はSiが耐酸化性あるいは応力腐食割れ
防止に優れた効果を発揮することによる。また、優れた
耐擦傷性を有する鋼としては、特公昭56−32387の鋼が
あり、その化学成分はCr:12〜19%、Ni:4〜12%、Mn7〜
12%、Si3〜5%、C:0.01〜0.12%、N:0.03〜0.3%で、
焼鈍時のオーステナイト組織を確保するためにSiの含有
量に直接比例した量のオーステナイト生成元素Niを含有
させてある。 さらに耐熱付性、耐掻疵性を有する鋼として特公昭56
−11379の鋼があり、その化学成分はCr:13〜25%、Ni:5
〜15%、Mn:0.5〜5.5%、Si:2.5〜5.0%、C:0.15%以
下、N:0.05〜0.20%で、潤滑剤が使用できない条件下で
の摺動部材に使用できるもので、SiとNの地質の強化な
らびにSiによる酸化被膜の生成とその自己回復性の強化
を利用するものである。 しかしながら、これらの高Si含有オーステナイト鋼は
溶接性ならびに冷間加工により硬化された状態での非磁
性の確保について全く考慮されていない。すなわち、こ
れらの鋼は成分系によっては溶接時の高温割れがはげし
く、また冷間加工によりマルテンサイトが生成するため
磁性を帯びるようになり、非磁性鋼としては使用できな
い。 〔問題解決の手段〕 本発明者等は多年Cr−Ni系オーステナイトステンレス
鋼の硬さ、透磁率と加工性に及ぼす合金元素、冷間加工
および熱処理の影響を調査した結果、SiおよびNは、冷
間加工あるいは冷間加工後適度の熱処理を施すことによ
り強度の増大をもたらすことを見出した。さらに、Siお
よびNを添加することで加工性が劣化するようになる
が、これにCuを添加することでSUS304並みの加工性を維
持できることを見出した。 すなわちCr−NiをベースにSiおよびNを添加し、さら
にCuを添加することで、加工性に優れ、かつ冷間加工後
の時効硬化能の大きい高強度非磁性ステンレス鋼を開発
することに成功した。 なお、本発明において非磁性とは透磁率が1.01以下の
ものをなす。 〔発明の構成と作用〕 本発明によれば、重量%で、 C:0.08%以下、 Si:3〜6%、 Mn:3〜9%、 Ni:10〜16%、 Cr:16〜22%、 N:0.05〜0.25%、 Cu:3%以下 を、含有し 残部Feならびに不純物からなり、次式 A(γ)=Ni+Cu+0.5Mn+30(C+N) −1.3Cr−2.6Si+11.8 で定義されるA(γ)値が −10<A(γ)<0 を満足し、かつ Ni当量=Ni+Cu+0.6Mn+9.69(C+N) +0.18Cr−0.11Si2 で定義されるNi当量の値が、最終焼鈍後に付与される冷
間加工量に応じて第1図に示される曲線A−Aより上の
範囲にあるように組成調整された鋼を溶製する工程、 最終焼鈍に供する鋼素材に加工する工程、 最終焼鈍工程、 冷間加工工程、 さらに必要に応じて、300〜600℃の範囲で時効処理を
行う工程からなる、 透磁率が1.01以下である加工性に優れた高強度非磁性
ステンレス鋼材料の製造方法、が提供される。 さらに本発明によれば、重量%で、 C:0.08%以下、 Si:3〜6%、 Mn:3〜9%、 Ni:10〜16%、 Cr:16〜22%、 N:0.05〜0.25%、 Cu:3%以下 を含有し、さらに Mo:3%以下 V:0.5%以下 Nb:0.5%以下 Ti:0.5%以下 のうち1種又は2種以上を含有し、 V+Nb+Tiの合計が0.5%以下 であり残部Feならびに不純物からなり次式 A(γ)=Ni+Cu+0.5Mn+30(C+N)−1.3Cr −2.6−Si1.3Mo−13(V+Nb+Ti)+11.8 で定義されるA(γ)値が −10<A(γ)<0 を満足し、かつ Ni当量=Ni+Cu+0.6Mn+9.69(C+N)+0.18Cr −0.11Si2+0.6Mo+2.3(V+Nb+Ti) で定義されるNi当量の値が、最終焼鈍後に付与される冷
間加工量に応じて第1図に示される曲線A−Aより上の
範囲にあるように組成調整された鋼を溶製する工程、 最終焼鈍に供する鋼素材に加工する工程、 最終焼鈍工程、 冷間加工工程、 さらに必要に応じて、300〜600℃の範囲で時効処理を
行う工程からなる、 透磁率が1.01以下である加工性に優れた高強度非磁性
ステンレス鋼材料の製造方法が提供される。 本発明において、CはNと同様に強力なオーステナイ
ト相安定化元素であり、かつ強度の向上に有効な元素で
あるが、反面Cは耐食性、溶接性を著しく低下させ、ま
た多量のCは加工性をも低下させるため、本発明の場
合、Cの上限は0.08%となる。 Siは本発明の主要な特徴である高強度を達成する有用
な元素であり、その目的を達成するためには少なくとも
約3%必要であるが、Si含有量が増加すると、加工性の
著しい低下を招くとともに、冷間加工後に鋼が磁性を帯
びるようになり、また熱間加工性が劣化するために上限
6%とする。 MnはNiと同様に冷間加工後の非磁性の維持に有効に働
き、かつ強化元素であるNの固溶度を高める元素であ
る。さらにMnは加工性を向上させる元素でもある。これ
らの性能を発揮するには約3%以上必要であり、また冷
間加工後の非磁性を保つためにSi含有量に応じてNi、Cu
とともにMnの含有量を調整する必要があるが、多量のMn
は溶接時の高温割れ感受性を高めるため上限を9%とす
る。 Niはオーステナイト鋼の基本成分でありオーステナイ
ト相の安定化に寄与し、また加工性を付与する元素であ
る。冷間加工後の非磁性を保つためには約10%以上必要
であり、さらにSi、Cu、Mnの含有量に応じて前記式のNi
当量を調整する必要がある。しかし多量のNi含有量はMn
およびCu同様、溶接時の高温割れ感受性を高めるため上
限を16%とする。 Crはステンレス鋼の基本成分であり、良好な耐食性を
得るためには約16%以上の含有が必要であるが、多量に
含有されると多量のδフェライトが生成し熱間加工性が
低下するとともに非磁性が確保できなくなるため上限を
22%とする。 Nは本発明鋼の主要な特徴である非磁性を維持し、か
つ高強度を得るために有効な元素である。これらの性能
を発揮させるには約0.05%以上含有させる必要がある。
しかし、0.25%を超えると健全な鋼塊が得られないので
これを上限とする。 Cuは本発明鋼の主要な特徴である加工性を付与するの
みならずオーステナイト相の安定化に寄与し冷間加工後
の非磁性を維持するものである。しかしながら、多量に
含有されると溶接時の高温割れ感受性が高くなるため上
限を3%とする。 Moは高強度化およびオーステナイト相の安定化に寄与
する有用な元素であるが、多量に添加すると、δフェラ
イト生成量が多くなり、非磁性を維持できなくなるため
上限を3%とする。 V、NbおよびTiは高強度化に寄与する有用な元素であ
るが、多量に添加すると加工性が著しく低下し、またδ
フェライト生成量が多くなり非磁性を確保できなくなる
ため、上限をそれぞれ0.5%かつ、V+Nb+Tiの合計を
0.5%以下とする。 A(γ)とNi当量の式とA(γ)の数値範囲は実験結
果に基ずいて導出されたものである。 すなわち、高Si、高Mn、高Niを含有するステンレス鋼
は1種の高合金鋼であり溶接時の高温割れを防止するに
は適量のδフェライトを生成させるよう組成を設計する
必要がある。そこで種々の実験を重ねた結果オーステナ
イト相の安定化指数A(γ)を前記のように定義し、そ
の値が前記のように0以下で良好な溶接性を確保するこ
とができることを見出した。しかしながら、該A(γ)
値が−10未満では多量のδフェライトが生成され、これ
が製品材にまで残存するため非磁性を確保できなくな
る。 また、前記のように定義されるNi当量は冷間加工に対
するオーステナイト相の安定度の指標であり、第1図に
見られるごとく、冷間圧延後の非磁性を確保するために
必要なNi当量の最小限の値は第1図の曲線A−Aで与え
られ、高度に冷間圧延される鋼ほど高いNi当量値を有す
る必要があることが分る。 以上の条件を満足するように組成調整された鋼を溶製
し、溶製された鋼を最終焼鈍に供する形状まで加工す
る。この加工方法は特に限定する必要はなく、周知の熱
間加工方法や冷間加工方法が適用できる。最終焼鈍は、
鋼が十分に軟化する条件で行えばよく、通常のオーステ
ナイト系ステンレス鋼で採用される焼鈍条件が適用でき
る。 以上のように本発明は高Si、高N、高Mnを含有するCr
−Ni系オーステナイトステンレス鋼に適量のCuを含有さ
せ、上記のように組成を調整することで鋼の加工性を付
与するとともに冷間加工、あるいは冷間加工と時効処理
を施すことにより、高強度化し、かつ冷間加工後の透磁
率が1.01以下に抑え得るものである。 第2図は本発明の20Cr−11Ni−2Cu−6Mn−4Si−0.05C
−0.17n鋼の60%冷間圧延後の硬さに及ぼす時効温度
(均熱時間、1時間)の影響を示す線図であるが、この
図から分るように時効処理は300〜600℃の範囲で行うこ
とが望ましい。これより低い温度域では時効効果がな
く、これより高い温度域では軟化が起こる。 〔実施例〕 第1表に示す組成を有する鋼を30kg溶製したのち10mm
厚、120mm巾に鍛造、1100℃で1時間の溶体化処理を行
い、これを3mmまで冷間圧延し、1050℃で5分の中間焼
鈍した後さらに1.5mmまで冷間圧延し、1070℃で2分間
の最終焼鈍を施した。 これらの焼鈍材の透磁率、引張特性ならびにビッカー
ス硬さを測定した。また、焼鈍材に60%の冷間圧延を施
した後のビッカース硬さ、透磁率と曲げ性、60%の冷間
圧延材に500℃で1時間の時効処理を施した後でのビッ
カース硬さを測定した。なおビッカース硬さは20kgの荷
重で測定し、透磁率は磁気天秤を溶いて1000エルステッ
ドの磁場のもとで測定した。 第2表は第1表の各鋼の焼鈍後の耐力、引張強さと伸
びおよび硬さ、60%冷間圧延後の硬さ、透磁率と曲げ
性、および60%冷間圧延後に500℃で1時間の熱処理を
施した後での硬さ、ならびに焼鈍材の溶接性の評価を示
す。ここで曲げ性についてはL方向の90゜突き曲げを行
い、R/t=1の曲げ加工後に割れが生じないものを○、
割れが生じるものを×とした。 また溶接性の評価は焼鈍材をTIG溶接後にカラーチェ
ックを行い、割れが観察されないものを○割れが観察さ
れるものとを×とした。 第2表から知られるように、従来鋼のA1鋼(SUS304)
とA2鋼(SUS316)の延性はそれぞれ54.7%、49.3%と高
く加工性も良好である。しかしながら、A1鋼は冷間圧延
後の透磁率が高いため非磁性を確保できず、またA2鋼
は、冷間圧延後、あるいは時効処理後の硬さが低いため
高強度材としては不十分である。比較鋼であるC1鋼はSU
S304と同様強度レベルは高いが冷間圧延後の透磁率は高
い。C2鋼は冷間圧延後の硬さも高く、かつ透磁率も1.01
以下と非磁性であるがA(γ)値が0以上であり溶接性
が著しく悪い。C3鋼はSiとNの含有量が高く、またC4鋼
はSiとNの含有量が高く、さらにVを含有しており冷間
圧延後時効処理を施すことにより高強度化でき、かつ冷
間圧延後の透磁率が1.01以下であり非磁性についても優
れているが、焼鈍材での延性が41〜43%と低く曲げ性も
悪い。 これらに対して本発明鋼であるB1〜5鋼はSi、Nの含
有量のみならずCu含有量も高いため延性が49〜52%と高
く、曲げ性も良好で、かつ冷間圧延後時効処理を施すこ
とにより硬さがHv470以上、特にB4鋼とB5鋼ではHv500以
上となる。またB6〜B15鋼はさらにMo、V、NbおよびTi
のうち1種又は2種以上含有しているため、さらに高強
度化されているが延性は46%、曲げ性も良好で比較鋼と
比べて依然優れた加工性を有している。また、透磁率は
前記式で 与えられるNi当量が19.0以上となるようNi、Mn、Cuおよ
びNを適量含有しており60%の冷間圧延を施した後でも
透磁率が1.01以下であり非磁性についても優れている。
さらに前記式で与えられるA(γ)値が−10〜0となる
よう組成調整されており溶接時の高温割れも発生せずか
つδフェライト生成量も適量で焼鈍材での非磁性も確保
できるものである。 〔発明の効果〕 本発明は、加工性に優れ冷間加工後および冷間加工後
時効処理を施した後での強度レベルが高くかつ冷間加工
後の透磁率が1.01以下である十分安定した非磁性を有す
るステンレス鋼材料を提供するものであり、特に、加工
性と高強度を必要とする電気機器部品や装置用の材料と
して極めて高い実用性を有する非磁性ステンレス鋼材料
を提供することが可能となった。
DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is for producing a non-magnetic stainless steel material having excellent workability and high strength, which is used in various devices and apparatuses that function by utilizing magnetic properties. Regarding the method. (Prior art and its problems) Cr-Ni austenitic stainless steel represented by SUS304 has good corrosion resistance and workability, and has a non-magnetic austenitic structure in the annealed state, so it can be used as a non-magnetic steel, Used for precision equipment parts. Some parts require strength and are used after cold working. However, since the austenite phase of SUS304 steel is metastable, martensitic transformation occurs during cold working and becomes magnetic. Therefore, for such a purpose, SUS316 in which the austenite phase is more stable is used. However, these Cr-Ni-based austenitic steels were not originally developed as non-magnetic steels, but general steels were merely diverted to non-magnetic applications. For example, SUS316, which has a more stable austenite phase, contains a large amount of expensive Ni and Mo, but although Mo exerts an excellent corrosion resistance effect, it does not contribute to high strength or non-magnetism. High Si content steels include heat resistant steels and stress corrosion cracking steels, and these steel types are based on the fact that Si exhibits excellent effects in oxidation resistance or prevention of stress corrosion cracking. Further, as a steel having excellent scratch resistance, there is a steel of Japanese Examined Patent Publication No. 56-32387, the chemical composition of which is Cr: 12-19%, Ni: 4-12%, Mn7-
12%, Si 3-5%, C: 0.01-0.12%, N: 0.03-0.3%,
In order to secure the austenite structure during annealing, the austenite forming element Ni is contained in an amount directly proportional to the Si content. Furthermore, as a steel with heat resistance and scratch resistance, Japanese Patent Publication Sho 56
-11379 steel, the chemical composition of which is Cr: 13-25%, Ni: 5
~ 15%, Mn: 0.5 ~ 5.5%, Si: 2.5 ~ 5.0%, C: 0.15% or less, N: 0.05 ~ 0.20%, which can be used for sliding members under conditions where lubricant cannot be used. It utilizes the strengthening of the geology of Si and N and the formation of oxide films by Si and its self-healing properties. However, these high Si content austenitic steels are not considered at all in terms of weldability and ensuring non-magnetism in the state hardened by cold working. That is, these steels are prone to high temperature cracking during welding depending on the component system, and become magnetic due to the formation of martensite by cold working, and cannot be used as non-magnetic steels. [Means for solving the problem] The present inventors have investigated the effects of alloy elements, cold working and heat treatment on the hardness, permeability and workability of a multi-year Cr-Ni austenitic stainless steel, and found that Si and N are: It has been found that strength is increased by performing cold working or moderate heat treatment after cold working. Further, it was found that the workability deteriorates by adding Si and N, but the workability comparable to SUS304 can be maintained by adding Cu to this. In other words, by adding Si and N on the basis of Cr-Ni and further adding Cu, we succeeded in developing a high-strength non-magnetic stainless steel with excellent workability and high age hardening after cold working. did. In addition, in the present invention, nonmagnetic means a magnetic permeability of 1.01 or less. [Structure and Action of the Invention] According to the present invention, in% by weight, C: 0.08% or less, Si: 3 to 6%, Mn: 3 to 9%, Ni: 10 to 16%, Cr: 16 to 22% , N: 0.05 to 0.25%, Cu: 3% or less, with the balance being Fe and impurities, A defined by the following formula: A (γ) = Ni + Cu + 0.5Mn + 30 (C + N) -1.3Cr-2.6Si + 11.8 (gamma) value -10 <a (gamma) satisfies <0, and the value of Ni equivalent = Ni + Cu + 0.6Mn + 9.69 (C + N) + 0.18Cr-0.11Si 2 defined in the Ni equivalent is, after the final annealing A step of smelting steel whose composition is adjusted so as to be in a range above the curve A-A shown in FIG. 1 according to the amount of cold working given, a step of processing into a steel material to be subjected to final annealing, A high-strength non-magnetic stainless steel material with a magnetic permeability of 1.01 or less, consisting of a final annealing step, a cold working step, and if necessary, an aging treatment in the range of 300 to 600 ° C. Production method, is provided. Further, according to the present invention, C: 0.08% or less, Si: 3 to 6%, Mn: 3 to 9%, Ni: 10 to 16%, Cr: 16 to 22%, N: 0.05 to 0.25, by weight. %, Cu: 3% or less, Mo: 3% or less, V: 0.5% or less, Nb: 0.5% or less, Ti: 0.5% or less, and one or more types are contained, and the total of V + Nb + Ti is 0.5%. A (γ) = Ni + Cu + 0.5Mn + 30 (C + N) -1.3Cr-2.6-Si1.3Mo-13 (V + Nb + Ti) +11.8 10 <a (γ) <satisfies 0, and the value of Ni equivalent = Ni + Cu + 0.6Mn + 9.69 (C + N) + 0.18Cr -0.11Si 2 + 0.6Mo + 2.3 (V + Nb + Ti) is defined by the Ni equivalent, final A step of smelting steel whose composition is adjusted so as to be in a range above the curve AA shown in FIG. 1 according to the amount of cold working given after annealing, and processing into a steel material to be subjected to final annealing Process, final annealing process, cold working Degree, optionally further comprising the step of performing an aging treatment in the range of 300 to 600 ° C., the method of producing a high-strength nonmagnetic stainless steel material permeability and excellent workability is 1.01 or less is provided. In the present invention, C is a strong austenite phase stabilizing element similar to N and is an element effective for improving strength. On the other hand, C significantly reduces corrosion resistance and weldability, and a large amount of C is processed. In the case of the present invention, the upper limit of C is 0.08% because it also lowers the property. Si is a useful element that achieves the high strength, which is the main feature of the present invention, and it is necessary to have at least about 3% to achieve its purpose. However, as the Si content increases, the workability decreases significantly. , The steel becomes magnetic after cold working, and the hot workability deteriorates, so the upper limit is 6%. Like Ni, Mn is an element that effectively works to maintain non-magnetism after cold working and increases the solid solubility of N as a strengthening element. Further, Mn is an element that improves workability. About 3% or more is required to exhibit these performances, and in order to maintain non-magnetism after cold working, Ni, Cu
It is necessary to adjust the Mn content with
Has an upper limit of 9% to increase the sensitivity to hot cracking during welding. Ni is a basic component of the austenitic steel and contributes to stabilization of the austenitic phase and is an element imparting workability. About 10% or more is required to maintain non-magnetism after cold working. Further, depending on the content of Si, Cu, Mn,
It is necessary to adjust the equivalent weight. However, a large amount of Ni content is Mn
Similarly to Cu and Cu, the upper limit is set to 16% to increase the sensitivity to hot cracking during welding. Cr is a basic component of stainless steel, and it is necessary to contain about 16% or more in order to obtain good corrosion resistance, but if it is contained in a large amount, a large amount of δ ferrite is generated and hot workability deteriorates. Together with non-magnetic properties,
22% N is an element effective for maintaining the non-magnetic property, which is a main feature of the steel of the present invention, and for obtaining high strength. In order to exhibit these performances, it is necessary to contain about 0.05% or more.
However, if it exceeds 0.25%, a sound steel ingot cannot be obtained, so the upper limit is set. Cu not only imparts the workability, which is the main feature of the steel of the present invention, but also contributes to the stabilization of the austenite phase and maintains the non-magnetism after cold working. However, if contained in a large amount, the sensitivity to hot cracking during welding increases, so the upper limit is set to 3%. Mo is a useful element that contributes to strengthening and stabilization of the austenite phase, but if added in a large amount, the amount of δ ferrite produced increases, and it becomes impossible to maintain non-magnetism, so the upper limit is made 3%. V, Nb and Ti are useful elements contributing to high strength, but when added in a large amount, workability is remarkably reduced, and δ
Since the amount of ferrite generated increases and it becomes impossible to secure non-magnetic properties, the upper limit is 0.5% and the sum of V + Nb + Ti is
0.5% or less. The formulas of A (γ) and Ni equivalent and the numerical range of A (γ) are derived based on experimental results. That is, the stainless steel containing high Si, high Mn, and high Ni is one kind of high alloy steel, and it is necessary to design the composition so as to generate an appropriate amount of δ ferrite in order to prevent hot cracking during welding. Therefore, as a result of various experiments, it was found that the stabilization index A (γ) of the austenite phase was defined as described above, and that the value was 0 or less as described above, and good weldability could be secured. However, the A (γ)
If the value is less than −10, a large amount of δ ferrite is generated, and since this remains in the product material, nonmagnetic properties cannot be secured. Further, the Ni equivalent defined as described above is an index of the stability of the austenite phase against cold working, and as shown in Fig. 1, the Ni equivalent required to secure non-magnetic property after cold rolling. The minimum value of is given by curve A-A in Figure 1 and it can be seen that the more highly cold rolled steel is required to have the higher Ni equivalent value. The steel whose composition is adjusted to satisfy the above conditions is melted, and the melted steel is processed into a shape to be subjected to final annealing. This working method is not particularly limited, and a known hot working method or cold working method can be applied. The final annealing is
What is necessary is just to carry out under conditions where the steel is sufficiently softened, and the annealing conditions adopted for ordinary austenitic stainless steel can be applied. As described above, the present invention provides Cr containing high Si, high N, and high Mn.
-Ni-based austenitic stainless steel contains an appropriate amount of Cu and adjusts the composition as described above to impart workability to the steel and perform high-strength processing by cold working or cold working and aging. And the magnetic permeability after cold working can be suppressed to 1.01 or less. FIG. 2 shows 20Cr-11Ni-2Cu-6Mn-4Si-0.05C of the present invention.
It is a diagram showing the effect of aging temperature (soaking time, 1 hour) on the hardness of -0.17n steel after 60% cold rolling. As can be seen from this figure, the aging treatment is 300-600 ℃. It is desirable to carry out within the range. There is no aging effect in a lower temperature range, and softening occurs in a higher temperature range. [Example] After melting 30 kg of steel having the composition shown in Table 1, 10 mm
Forged to a thickness of 120 mm, subjected to a solution treatment at 1100 ° C for 1 hour, cold-rolled to 3 mm, intermediately annealed at 1050 ° C for 5 minutes, and then cold-rolled to 1.5 mm, and then to 1070 ° C. A final annealing of 2 minutes was performed. The magnetic permeability, tensile properties and Vickers hardness of these annealed materials were measured. Vickers hardness, permeability and bendability after 60% cold rolling of the annealed material, and Vickers hardness after aging treatment of the 60% cold rolled material at 500 ° C for 1 hour. Was measured. The Vickers hardness was measured with a load of 20 kg, and the magnetic permeability was measured under a magnetic field of 1000 Oersted by melting a magnetic balance. Table 2 shows the yield strength, tensile strength, elongation and hardness of each steel in Table 1 after annealing, hardness after 60% cold rolling, permeability and bendability, and at 500 ° C after 60% cold rolling. The hardness after the heat treatment for one hour and the weldability of the annealed material are shown. Here, regarding bendability, the case where a 90 ° butt bend in the L direction was performed and cracks did not occur after bending with R / t = 1, ○,
Those that caused cracks were marked with x. The weldability was evaluated by performing a color check on the annealed material after TIG welding, and those in which cracks were not observed were evaluated as ○ and those in which cracks were observed were evaluated as ×. As is known from Table 2, conventional steel A1 steel (SUS304)
And A2 steel (SUS316) have high ductility of 54.7% and 49.3%, respectively, and have good workability. However, A1 steel cannot secure non-magnetism due to its high magnetic permeability after cold rolling, and A2 steel is insufficient as a high strength material due to its low hardness after cold rolling or after aging treatment. is there. Comparative steel C1 steel is SU
Like S304, its strength level is high, but its magnetic permeability after cold rolling is high. C2 steel has a high hardness after cold rolling and a magnetic permeability of 1.01
The following are non-magnetic, but the A (γ) value is 0 or more, and the weldability is extremely poor. C3 steel has a high content of Si and N, C4 steel has a high content of Si and N, and further contains V, so that it can be strengthened by cold-rolling aging treatment, The magnetic permeability after rolling is 1.01 or less and it is excellent in non-magnetism as well, but the ductility of the annealed material is low at 41 to 43% and the bendability is poor. On the other hand, the B1 to 5 steels of the present invention have high Cu content as well as Si and N contents, and thus have high ductility of 49 to 52%, good bendability, and aged after cold rolling. By performing the treatment, the hardness becomes Hv470 or more, and particularly Hv500 or more for B4 steel and B5 steel. B6 to B15 steels are also Mo, V, Nb and Ti.
Of these steels, one or more of them are included, so that the strength is further enhanced, but the ductility is 46%, the bendability is good, and the workability is still superior to that of the comparative steel. The magnetic permeability is It contains an appropriate amount of Ni, Mn, Cu and N so that the given Ni equivalent is 19.0 or more, and has a magnetic permeability of 1.01 or less even after cold rolling of 60%, and is excellent in non-magnetic properties.
Further, the composition is adjusted so that the A (γ) value given by the above formula is -10 to 0, no high-temperature cracking occurs during welding, an appropriate amount of δ ferrite is formed, and non-magnetism in the annealed material can be secured. It is a thing. [Effect of the Invention] The present invention is excellent in workability, has a sufficiently high strength level after cold working and after aging treatment after cold working, and has a sufficiently stable magnetic permeability after cold working of 1.01 or less. It is intended to provide a non-magnetic stainless steel material having non-magnetic properties, and in particular, to provide a non-magnetic stainless steel material having extremely high practicality as a material for electrical equipment parts and devices requiring workability and high strength. It has become possible.
【図面の簡単な説明】 第1図は本発明の鋼において非磁性を維持するに必要な
最小限のNi当量と冷間圧延率の関係を示す。 第2図は本発明の20Cr−11Ni−2Cu−6Mn−4Si−0.05C−
0.17N鋼の60%冷間加工後の硬さに及ぼす時効温度(均
熱時間1時間)の影響を示す線図である。
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the relationship between the minimum Ni equivalent required to maintain non-magnetism and the cold rolling rate in the steel of the present invention. FIG. 2 shows 20Cr-11Ni-2Cu-6Mn-4Si-0.05C- according to the present invention.
FIG. 3 is a diagram showing the effect of aging temperature (soaking time: 1 hour) on the hardness of a 0.17N steel after 60% cold working.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭50−30727(JP,A) 特開 昭54−81118(JP,A) 特開 昭58−64356(JP,A) 特開 昭59−76824(JP,A) 特公 昭59−53343(JP,B2) 特公 昭51−29858(JP,B2)   ────────────────────────────────────────────────── ─── Continuation of front page    (56) References JP-A-50-30727 (JP, A)                 JP-A-54-81118 (JP, A)                 JP-A-58-64356 (JP, A)                 JP-A-59-76824 (JP, A)                 Tokiko Sho 59-53343 (JP, B2)                 Tokiko Sho 51-29858 (JP, B2)

Claims (1)

  1. (57)【特許請求の範囲】 1.重量%で、 C:0.08%以下、 Si:3〜6%、 Mn:3〜9%、 Ni:10〜16%、 Cr:16〜22%、 N:0.05〜0.25%、 Cu:3%以下 を、含有し 残部Feならびに不純物からなり、次式 A(γ)=Ni+Cu+0.5Mn+30(C+N) −1.3Cr−2.6Si+11.8 で定義されるA(γ)値が −10<A(γ)<0 を満足し、かつ Ni当量=Ni+Cu+0.6Mn+9.69(C+N) +0.18Cr−0.11Si2 で定義されるNi当量の値が、最終焼鈍後に付与される冷
    間加工量に応じて第1図に示される曲線A−Aより上の
    範囲にあるように組成調整された鋼を溶製する工程、 最終焼鈍に供する鋼素材に加工する工程、 最終焼鈍工程、 冷間加工工程からなる、 透磁率が1.01以下である加工性に優れた高強度非磁性ス
    テンレス鋼材料の製造方法。 2.重量%で、 C:0.08%以下、 Si:3〜6%、 Mn:3〜9%、 Ni:10〜16%、 Cr:16〜22%、 N:0.05〜0.25%、 Cu:3%以下 を含有し、さらに Mo:3%以下 V:0.5%以下 Nb:0.5%以下 Ti:0.5%以下 のうち1種又は2種以上を含有し、 V+Nb+Tiの合計が0.5%以下 であり残部Feならびに不純物からなり次式 A(γ)=Ni+Cu+0.5Mn+30(C+N)−1.3Cr −2.6Si−1.3Mo−13(V+Nb+Ti)+11.8 で定義されるA(γ)値が −10<A(γ)<0 を満足し、かつ Ni当量=Ni+Cu+0.6Mn+9.69(C+N)+0.18Cr −0.11Si2+0.6Mo+2.3(V+Nb+Ti) で定義されるNi当量の値が、最終焼鈍後に付与される冷
    間加工量に応じて第1図に示される曲線A−Aより上の
    範囲にあるように組成調整された鋼を溶製する工程、 最終焼鈍に供する鋼素材に加工する工程、 最終焼鈍工程、 冷間加工工程からなる、 透磁率が1.01以下である加工性に優れた高強度非磁性ス
    テンレス鋼材料の製造方法。 3.重量%で、 C:0.08%以下、 Si:3〜6%、 Mn:3〜9%、 Ni:10〜16%、 Cr:16〜22%、 N:0.05〜0.25%、 Cu:3%以下 を、含有し 残部Feならびに不純物からなり、次式 A(γ)=Ni+Cu+0.5Mn+30(C+N) −1.3Cr−2.6Si+11.8 で定義されるA(γ)値が −10<A(γ)<0 を満足し、かつ Ni当量=Ni+Cu+0.6Mn+9.69(C+N) +0.18Cr−0.11Si2 で定義されるNi当量の値が、最終焼鈍後に付与される冷
    間加工量に応じて第1図に示される曲線A−Aより上の
    範囲にあるように組成調整された鋼を溶製する工程、 最終焼鈍に供する鋼素材に加工する工程、 最終焼鈍工程、 冷間加工工程、 300〜600℃の範囲で時効処理を行う工程からなる、 透磁率が1.01以下である加工性に優れた高強度非磁性ス
    テンレス鋼材料の製造方法。 4.】重量%で、 C:0.08%以下、 Si:3〜6%、 Mn:3〜9%、 Ni:10〜16%、 Cr:16〜22%、 N:0.05〜0.25%、 Cu:3%以下 を含有し、さらに Mo:3%以下 V:0.5%以下 Nb:0.5%以下 Ti:0.5%以下 のうち1種又は2種以上を含有し、 V+Nb+Tiの合計が0.5%以下 であり残部Feならびに不純物からなり次式 A(γ)=Ni+Cu+0.5Mn+30(C+N)−1.3Cr −2.6−Si1.3Mo−13(V+Nb+Ti)+11.8 で定義されるA(γ)値が −10<A(γ)<0 を満足し、かつ Ni当量=Ni+Cu+0.6Mn+9.69(C+N)+0.18Cr −0.11Si2+0.6Mo+2.3(V+Nb+Ti) で定義されるNi当量の値が、最終焼鈍後に付与される冷
    間加工量に応じて第1図に示される曲線A−Aより上の
    範囲にあるように組成調整された鋼を溶製する工程、 最終焼鈍に供する鋼素材に加工する工程、 最終焼鈍工程、 冷間加工工程、 300〜600℃の範囲で時効処理を行う工程からなる、 透磁率が1.01以下である加工性に優れた高強度非磁性ス
    テンレス鋼材料の製造方法。
    (57) [Claims] % By weight, C: 0.08% or less, Si: 3 to 6%, Mn: 3 to 9%, Ni: 10 to 16%, Cr: 16 to 22%, N: 0.05 to 0.25%, Cu: 3% or less And the balance is Fe and impurities, and the A (γ) value defined by the following formula A (γ) = Ni + Cu + 0.5Mn + 30 (C + N) −1.3Cr−2.6Si + 11.8 has a value of −10 <A (γ) < satisfies 0, and the value of Ni equivalent = Ni + Cu + 0.6Mn + 9.69 (C + N) + 0.18Cr-0.11Si 2 Ni eq defined in the first diagram in accordance with the cold working amounts to be applied after the final annealing Permeability, which consists of the steps of smelting the steel whose composition has been adjusted so that it is in the range above the curve A-A shown in, the step of processing into the steel material to be subjected to final annealing, the final annealing step, and the cold working step. A method for producing a high-strength non-magnetic stainless steel material excellent in workability, having a value of 1.01 or less. 2. % By weight, C: 0.08% or less, Si: 3 to 6%, Mn: 3 to 9%, Ni: 10 to 16%, Cr: 16 to 22%, N: 0.05 to 0.25%, Cu: 3% or less Mo: 3% or less, V: 0.5% or less, Nb: 0.5% or less, Ti: 0.5% or less, and one or more types are contained, and the total of V + Nb + Ti is 0.5% or less and the balance Fe and impurities. A (γ) = Ni + Cu + 0.5Mn + 30 (C + N) −1.3Cr−2.6Si−1.3Mo−13 (V + Nb + Ti) +11.8 where A (γ) is −10 <A (γ) < satisfies 0, and Ni value of equivalent = Ni + Cu + 0.6Mn + 9.69 (C + N) + 0.18Cr -0.11Si 2 + 0.6Mo + 2.3 (V + Nb + Ti) is defined by the Ni equivalent, cold applied after final annealing The step of producing a steel whose composition is adjusted so as to be in the range above the curve A-A shown in FIG. 1 according to the working amount, the step of working into the steel material to be subjected to the final annealing, the final annealing step, the cooling It has a magnetic permeability of 1 A method for producing a high-strength non-magnetic stainless steel material having excellent workability of 0.01 or less. 3. % By weight, C: 0.08% or less, Si: 3 to 6%, Mn: 3 to 9%, Ni: 10 to 16%, Cr: 16 to 22%, N: 0.05 to 0.25%, Cu: 3% or less And the balance is Fe and impurities, and the A (γ) value defined by the following formula A (γ) = Ni + Cu + 0.5Mn + 30 (C + N) −1.3Cr−2.6Si + 11.8 has a value of −10 <A (γ) < satisfies 0, and the value of Ni equivalent = Ni + Cu + 0.6Mn + 9.69 (C + N) + 0.18Cr-0.11Si 2 Ni eq defined in the first diagram in accordance with the cold working amounts to be applied after the final annealing The process of smelting the steel whose composition is adjusted so as to be in the range above the curve A-A shown in Fig. 4, the process of processing the steel material to be subjected to final annealing, the final annealing process, the cold working process, 300-600 ℃ A method for producing a high-strength non-magnetic stainless steel material excellent in workability and having a magnetic permeability of 1.01 or less, comprising a step of performing an aging treatment in the range described above. 4. % By weight, C: 0.08% or less, Si: 3 to 6%, Mn: 3 to 9%, Ni: 10 to 16%, Cr: 16 to 22%, N: 0.05 to 0.25%, Cu: 3% Contains: Mo: 3% or less, V: 0.5% or less, Nb: 0.5% or less, Ti: 0.5% or less, and one or more of them are contained. The total of V + Nb + Ti is 0.5% or less and the balance Fe and The value of A (γ) which is composed of impurities and is defined by the following equation A (γ) = Ni + Cu + 0.5Mn + 30 (C + N) -1.3Cr-2.6-Si1.3Mo-13 (V + Nb + Ti) +11.8 is -10 <A (γ) <satisfies 0, and cold values of Ni equivalent = Ni + Cu + 0.6Mn + 9.69 (C + N) + 0.18Cr -0.11Si 2 + 0.6Mo + 2.3 (V + Nb + Ti) is defined by the Ni equivalent is applied after the final annealing A step of producing a steel whose composition is adjusted so as to be in a range above the curve A-A shown in FIG. 1 according to the interworking amount, a step of processing a steel material to be subjected to final annealing, a final annealing step, Cold working process, 300-600 ℃ range Comprising the step of performing an aging treatment, high strength method for producing a non-magnetic stainless steel material permeability and excellent workability is 1.01 or less.
JP61182039A 1986-08-04 1986-08-04 Method for producing high-strength non-magnetic stainless steel material with excellent workability Expired - Lifetime JP2668113B2 (en)

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