JPH11279711A - Ferritic stainless steel low in working crack sensitivity and its production - Google Patents
Ferritic stainless steel low in working crack sensitivity and its productionInfo
- Publication number
- JPH11279711A JPH11279711A JP8099298A JP8099298A JPH11279711A JP H11279711 A JPH11279711 A JP H11279711A JP 8099298 A JP8099298 A JP 8099298A JP 8099298 A JP8099298 A JP 8099298A JP H11279711 A JPH11279711 A JP H11279711A
- Authority
- JP
- Japan
- Prior art keywords
- weight
- composition
- stainless steel
- less
- concentration
- 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
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、加工割れ感受性が低い
フェライト系ステンレス鋼及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferritic stainless steel having low work cracking susceptibility and a method for producing the same.
【０００２】[0002]
【従来の技術】ＳＵＳ４３０等のフェライト系ステンレ
ス鋼は、薄板製品として極めて広範な用途に使用されて
いる。近年では機能材料としても使用されるようになっ
てきているが、電子部品用としての用途では高い清浄度
が素材に要求される。清浄度は、精錬工程で溶鋼を撹拌
させることにより改善される。非金属介在物は、溶鋼の
撹拌によってスラグ，フラックス，耐火物等に吸着さ
れ、溶鋼から浮上分離する。また、溶鋼撹拌時に、Ｃａ
Ｏを主体とする塩基性フラックス及びＡｌ等の強還元剤
を添加することも実施されている。2. Description of the Related Art Ferritic stainless steels such as SUS430 are used in a very wide range of applications as sheet products. In recent years, it has also been used as a functional material, but for use as an electronic component, a high cleanness is required for the material. Cleanliness is improved by stirring the molten steel in the refining process. The nonmetallic inclusions are adsorbed on slag, flux, refractory, etc. by stirring the molten steel and float and separate from the molten steel. Also, when stirring molten steel, Ca
It has also been practiced to add a basic flux mainly composed of O and a strong reducing agent such as Al.
【０００３】[0003]
【発明が解決しようとする課題】電子部品向けの用途で
は、素材の品質に対する要求度が一層苛酷になってきて
おり、高性清浄化だけでは対応困難なケースも生じてい
る。たとえば、板厚０．５ｍｍ以下の極薄板で製品形状
が複雑なものでは、非金属介在物の影響度が大きく現れ
る。なかでも、硬質の非金属介在物が存在すると、製品
に割れ，表面疵等の欠陥が発生し易くなる。非金属介在
物は、組成に応じて硬さが大きく変わるが、従来の清浄
化法では非金属介在物の組成を制御できない。本発明
は、このような問題を解消すべく案出されたものであ
り、非金属介在物の組成を制御することにより、熱間加
工時に粘性変形し冷間加工時に微細分散するＭｎＯ−Ｓ
ｉＯ2 系にし、非金属介在物起因の加工割れがないフェ
ライト系ステンレス鋼を得ることを目的とする。In applications for electronic parts, the requirements for the quality of the raw materials have become more severe, and there have been cases where it is difficult to cope with only high-grade cleaning. For example, in the case of an extremely thin plate having a thickness of 0.5 mm or less and having a complicated product shape, the degree of influence of nonmetallic inclusions appears significantly. Above all, if hard nonmetallic inclusions are present, defects such as cracks and surface flaws are likely to occur in the product. The hardness of nonmetallic inclusions greatly changes depending on the composition, but the composition of the nonmetallic inclusions cannot be controlled by conventional cleaning methods. The present invention has been devised to solve such a problem, and by controlling the composition of nonmetallic inclusions, MnO—S that viscously deforms during hot working and finely disperses during cold working.
An object is to obtain a ferritic stainless steel that is made of iO 2 and free from work cracks caused by nonmetallic inclusions.
【０００４】[0004]
【課題を解決するための手段】本発明のフェライト系ス
テンレス鋼は、その目的を達成するため、Ｃ：０．１重
量％以下，Ｓｉ：０．１〜１．０重量％，Ｍｎ：０．１
〜１．０重量％，Ｃｒ：１０〜３２重量％，Ａｌ：０．
００３重量％以下，残部が実質的にＦｅの組成を持ち、
Ｓｉ／Ａｌの重量比が１００以上で、非金属介在物の組
成がＭｎＯ−ＳｉＯ2 を主成分とし、ＭｇＯ：７重量％
以下，Ａｌ2 Ｏ3 ：３５重量％以下，Ｃｒ2 Ｏ3 ：１０
重量％以下であることを特徴とする。このフェライト系
ステンレス鋼は、ドロマイト系耐火物をライニングした
精錬容器にステンレス溶鋼を装入し、精錬終了時にＣａ
Ｏ／ＳｉＯ2 の重量比１．４〜２．４，Ａｌ2 Ｏ3 濃度
８重量％以下の組成となるスラグを用いて精錬すること
により溶製される。In order to achieve the object, the ferritic stainless steel of the present invention has a C content of 0.1% by weight or less, a Si content of 0.1 to 1.0% by weight, and a Mn content of 0.1% by weight. 1
To 1.0% by weight, Cr: 10 to 32% by weight, Al: 0.
003% by weight or less, with the balance having substantially the composition of Fe,
When the weight ratio of Si / Al is 100 or more, the composition of the nonmetallic inclusions is mainly composed of MnO—SiO 2 , and MgO: 7% by weight
Below, Al 2 O 3 : 35% by weight or less, Cr 2 O 3 : 10
% By weight or less. This ferritic stainless steel is prepared by charging molten stainless steel into a smelting vessel lined with dolomite-based refractory, and adding Ca
It is melted by refining using a slag having a composition of O / SiO 2 weight ratio of 1.4 to 2.4, Al 2 O 3 concentration of 8% by weight or less.
【０００５】[0005]
【作用】本発明者等は、フェライト系ステンレス鋼に絞
り加工を施して得た製品について、非金属介在物に由来
する加工割れが発生しているものを調査した。フェライ
ト系ステンレス鋼に分散している非金属介在物はＭｇＯ
−Ａｌ2 Ｏ3系，ＭｎＯ−ＳｉＯ2 −Ａｌ2 Ｏ3 系，Ｍ
ｎＯ−Ｃｒ2 Ｏ3 系等である。本発明者等による調査・
研究の結果、これらの介在物に含まれるＭｇＯ濃度，Ａ
ｌ2 Ｏ 3 濃度及びＣｒ2 Ｏ3 濃度が加工割れに大きく影
響していることが判った。そして、ＭｎＯ−ＳｉＯ2 を
主成分とする非金属介在物を生成させると共に、Ｍｇ
Ｏ：１０重量％以下，Ａｌ2 Ｏ3 ：４０重量％以下，Ｃ
ｒ2 Ｏ3 ：１０重量％以下に調整するとき、非金属介在
物が無害化し、加工割れ感受性の低いフェライト系ステ
ンレス鋼が得られることを見出した。更に、介在物組成
に影響を及ぼす因子としてメタル組成，スラグ組成，耐
火物組成等について検討を進めたところ、精錬終了後の
スラグ組成及び精錬容器の耐火物組成を特定することが
有効であることが判った。[Function] The present inventors focused on ferritic stainless steel.
Of non-metallic inclusions in products obtained by reworking
Investigations were made on the occurrence of processing cracks. Ferai
Non-metallic inclusions dispersed in stainless steel
-AlTwo OThreeSystem, MnO-SiOTwo -AlTwo OThree System, M
nO-CrTwo OThree System. Investigation by the present inventors
As a result of the study, the concentration of MgO contained in these inclusions, A
lTwo O Three Concentration and CrTwo OThree Concentration greatly affects machining cracks
It turned out that it was echoing. And MnO-SiOTwo To
While producing non-metallic inclusions as the main component, Mg
O: 10% by weight or less, AlTwo OThree : 40% by weight or less, C
rTwo OThree : When adjusted to 10% by weight or less, non-metallic
Detoxification of ferrite-based steel
Stainless steel was obtained. Furthermore, the inclusion composition
Factors affecting the metal composition, slag composition,
After examining the composition of the fire, etc.,
It is possible to specify the slag composition and the refractory composition of the smelting vessel.
It proved to be effective.
【０００６】以下、本発明フェライト系ステンレス鋼に
含まれる合金成分，含有量等を説明する。 Ｃ：０．１重量％以下 固溶強化元素であり、多量に含まれると０．２％耐力が
上昇し、鋼材を硬質化する。絞り加工が要求される鋼材
では、耐力及び硬さの上昇により加工性が阻害される。
また、Ｃ濃度が高いと結晶粒界に析出する炭化物が増加
し、耐食性を劣化させる原因になる。そこで、本発明に
おいては、Ｃ含有量の上限を０．１重量％に設定した。 Ｓｉ：０．１〜１．０重量％ 溶鋼の脱酸に使用される成分であり、非金属介在物の形
態に大きな影響を及ぼす。Ｓｉ含有量が０．１重量％に
満たないと、脱酸不足となり、非金属介在物中のＣｒ2
Ｏ3 濃度が１０重量％を超えるようになり、加工割れを
誘発させる非金属介在物が生成し易くなる。しかし、
１．０重量％を超える多量のＳｉが含まれると、鋼材が
硬質化し、冷間加工で薄板を製造する際に所定板厚まで
圧延するために多くのパス回数を必要とし、生産性が大
きく低下する。また、材料コストを上げる原因にもな
る。Hereinafter, alloy components, contents, and the like contained in the ferritic stainless steel of the present invention will be described. C: 0.1% by weight or less Solid solution strengthening element. When contained in a large amount, the proof stress increases by 0.2%, and hardens the steel material. In steel materials that require drawing, workability is impaired due to increases in proof stress and hardness.
Further, when the C concentration is high, carbides precipitated at the crystal grain boundaries increase, which causes deterioration of corrosion resistance. Therefore, in the present invention, the upper limit of the C content is set to 0.1% by weight. Si: 0.1 to 1.0% by weight It is a component used for deoxidizing molten steel and has a great effect on the form of nonmetallic inclusions. If the Si content is less than 0.1% by weight, deoxidation becomes insufficient and Cr 2 in nonmetallic inclusions becomes insufficient.
The O 3 concentration exceeds 10% by weight, and nonmetallic inclusions that induce work cracking are easily generated. But,
When a large amount of Si exceeding 1.0% by weight is contained, the steel material becomes hard and requires a large number of passes to roll to a predetermined thickness when manufacturing a thin plate by cold working, thereby increasing productivity. descend. It also causes an increase in material costs.
【０００７】Ｍｎ：０．１〜１．０重量％ ＭｎＯ−ＳｉＯ2 を主成分とする組成に非金属介在物を
制御するために重要な合金成分である。Ｍｎ含有量が
０．１重量％に満たないと、非金属介在物をＭｎＯ−Ｓ
ｉＯ2 系の組成に調節することが困難になる。このよう
な効果は、Ｍｎ含有量１．０重量％で飽和し、それ以上
にＭｎ含有量を増加してもＳｉと同様に材料コストを上
げる原因になる。 Ｃｒ：１０〜３２重量％ 耐食性の改善に必要な合金成分であり、１０重量％以上
の含有量でＣｒ添加の効果が顕著になる。しかし、過剰
量のＣｒが含まれると鋼材が硬質化し、加工性が劣化す
ることから、本発明ではＣｒ含有量の上限を３２重量％
に設定した。Mn: 0.1-1.0% by weight Mn is an important alloy component for controlling nonmetallic inclusions in a composition mainly composed of MnO—SiO 2 . When the Mn content is less than 0.1% by weight, non-metallic inclusions are reduced to MnO—S
It becomes difficult to adjust the composition to iO 2 . Such an effect is saturated at an Mn content of 1.0% by weight, and even if the Mn content is further increased, the material cost is increased similarly to Si. Cr: 10 to 32% by weight An alloy component necessary for improving corrosion resistance. When the content is 10% by weight or more, the effect of adding Cr becomes remarkable. However, if an excessive amount of Cr is contained, the steel material becomes hard and the workability deteriorates. Therefore, in the present invention, the upper limit of the Cr content is set to 32% by weight.
Set to.
【０００８】Ａｌ：０．００３重量％以下 非金属介在物の組成に大きな影響を与える合金成分であ
る。Ａｌ含有量が０．００３重量％を超えると、加工割
れの原因となるＭｇＯ−Ａｌ2 Ｏ3 系のスピネル型非金
属介在物が生成し易くなる。 Ｓｉ／Ａｌの重量比：１００以上 加工割れの起点となる非金属介在物の組成は、Ｓｉ／厚
みの重量比で調整できる。Ｓｉ／Ａｌの重量比が１００
以上になると、熱間加工時に粘性変形し、冷間加工時に
微細分散するＭｎＯ−ＳｉＯ2 系の非金属介在物が生成
する。他方、Ｓｉ／Ａｌの重量比が１００に満たないと
有害な非金属介在物が生成する。Al: 0.003% by weight or less Al is an alloy component that greatly affects the composition of nonmetallic inclusions. If Al content exceeds 0.003 wt%, spinel nonmetallic inclusions MgO-Al 2 O 3 system causing machining cracks are easily generated. The weight ratio of Si / Al: 100 or more The composition of the nonmetallic inclusions that are the starting points of working cracks can be adjusted by the weight ratio of Si / thickness. Si / Al weight ratio of 100
As a result, MnO—SiO 2 non-metallic inclusions that undergo viscous deformation during hot working and finely disperse during cold working are generated. On the other hand, when the weight ratio of Si / Al is less than 100, harmful nonmetallic inclusions are generated.
【０００９】本発明は、以上に掲げた合金成分の外に、
必要に応じて他の合金成分を含むこともできる。たとえ
ば、耐食性，加工性等を改善する場合、０．２〜５重量
％のＭｏ，０．２〜０．５重量％のＣｕ，０．１〜０．
５重量％のＮｂ等の１種又は２種以上を添加しても良
い。[0009] The present invention, in addition to the above listed alloy components,
Other alloy components may be included as needed. For example, when improving corrosion resistance, workability, etc., 0.2 to 5% by weight of Mo, 0.2 to 0.5% by weight of Cu, 0.1 to 0.1%.
One or more of 5% by weight of Nb or the like may be added.
【００１０】非金属介在物：ＭｎＯ−ＳｉＯ2 系にする
ことにより非金属介在物は無害化されるが、更にＭｇ
Ｏ：１０重量％以下，Ａｌ2 Ｏ3 ：４０重量％以下，Ｃ
ｒ2 Ｏ3 ：１０重量％以下にすることにより加工割れ感
受性が一層改善される。ＭｇＯは、耐火物やスラグに含
まれており、不可避的に非金属介在物中に含まれること
が多い。ＭｇＯ濃度が１０重量％を超えると、非金属介
在物が熱間加工中に粘性変形しなくなり、加工割れの原
因になり易い。このような欠陥は、ＭｇＯ濃度を１０重
量％以下にすることにより抑制される。Ａｌ2 Ｏ3 は、
種々の添加原料に含まれているＡｌから生成すると考え
られるが、Ａｌ2 Ｏ3 も非金属介在物中の濃度により非
金属介在物の変形能に大きな影響を及ぼす。Ａｌ2 Ｏ3
濃度が４０重量％よりも高いと有害な非金属介在物が生
成されるが、４０重量％以下であると非金属介在物は熱
間圧延で粘性変形し、冷間圧延で微細分散するため加工
割れを発生させることがない。Ｃｒ2 Ｏ3 は、１０重量
％を超える濃度では加工割れ原因の非金属介在物となる
が、１０重量％以下の濃度では無害な非金属介在物とな
る。Non-metallic inclusions: Non-metallic inclusions are rendered harmless by using MnO—SiO 2 system.
O: 10% by weight or less, Al 2 O 3 : 40% by weight or less, C
By setting the content of r 2 O 3 to 10% by weight or less, the sensitivity to work cracking is further improved. MgO is contained in refractories and slag, and is often inevitably contained in nonmetallic inclusions. If the MgO concentration exceeds 10% by weight, the nonmetallic inclusions do not undergo viscous deformation during hot working, and tend to cause work cracking. Such defects are suppressed by setting the MgO concentration to 10% by weight or less. Al 2 O 3 is
Although it is considered that Al 2 O 3 is formed from Al contained in various additive materials, the concentration of Al 2 O 3 in the non-metallic inclusions also has a great effect on the deformability of the non-metallic inclusions. Al 2 O 3
When the concentration is higher than 40% by weight, harmful non-metallic inclusions are generated. However, when the concentration is less than 40% by weight, the non-metallic inclusions are viscously deformed by hot rolling and finely dispersed by cold rolling. No cracks occur. Cr 2 O 3 becomes non-metallic inclusions that cause work cracking at a concentration exceeding 10% by weight, but becomes harmless non-metallic inclusions at a concentration of 10% by weight or less.
【００１１】精錬終了時のスラグ組成：精錬終了時のス
ラグ組成も、非金属介在物の組成に大きな影響を及ぼ
す。スラグ中のＣａＯ／ＳｉＯ2 比が１．４よりも低
く、且つＡｌ2 Ｏ3 濃度が８重量％以下の場合、加工割
れに悪影響を及ぼす非金属介在物中のＣｒ2 Ｏ3 濃度が
１０重量％を超えて含まれることがあり、加工割れの原
因になり易い。また、ＣａＯ／ＳｉＯ2 比が１．４より
低く且つＡｌ2 Ｏ3 濃度が８重量％を超えると、ＭｎＯ
−Ａｌ2 Ｏ3 系の非金属介在物が生成し易くなる。Ｍｎ
Ｏ−Ａｌ2 Ｏ3 系非金属介在物は、変形能が良好でない
ため加工割れの原因になる。一方、ＣａＯ／ＳｉＯ2 比
が２．４を超えるようなスラグ組成では、代表的な硬質
非金属介在物であるＭｇＯ−Ａｌ2 Ｏ3 系スピネル型非
金属介在物が生成し易くなる。このようなことから、ス
ラグ組成は、ＣａＯ／ＳｉＯ2 比を１．４〜２．４の範
囲に、Ａｌ2 Ｏ3 濃度を８重量％以下にする必要があ
る。Slag composition at the end of refining: Slag composition at the end of refining also has a significant effect on the composition of nonmetallic inclusions. When the CaO / SiO 2 ratio in the slag is lower than 1.4 and the Al 2 O 3 concentration is 8% by weight or less, the Cr 2 O 3 concentration in the non-metallic inclusion which adversely affects the work crack is 10% by weight. %, Which is likely to cause processing cracks. When the CaO / SiO 2 ratio is lower than 1.4 and the Al 2 O 3 concentration exceeds 8% by weight, MnO
—Al 2 O 3 -based nonmetallic inclusions are easily generated. Mn
O-Al 2 O 3 based nonmetallic inclusions cause machining cracks for deformability is not good. On the other hand, when the slag composition has a CaO / SiO 2 ratio of more than 2.4, MgO—Al 2 O 3 spinel-type nonmetallic inclusions, which are typical hard nonmetallic inclusions, are likely to be generated. For this reason, the slag composition needs to have a CaO / SiO 2 ratio in the range of 1.4 to 2.4 and an Al 2 O 3 concentration of 8% by weight or less.
【００１２】精錬容器の耐火物：ＭｇＯ含有量が５０〜
８５重量％で残部の主成分がＣｒ2 Ｏ3 のマグクロ系耐
火物を取鍋耐火物として用いた場合、スラグ中のＣａＯ
／ＳｉＯ2 比が１．９を超えると耐火物の溶損が大きく
なり、スラグ中のＭｇＯ濃度が上昇するため、非金属介
在物中のＭｇＯ濃度が高くなる。その結果、加工割れを
招く非金属介在物になる可能性が高い。これに対し、Ｍ
ｇＯ含有量が４０〜６３重量％で残部の主成分がＣａＯ
であるドロマイト系耐火物は、スラグ中のＣａＯ／Ｓｉ
Ｏ2 比の上昇によっても耐火物の溶損が加速されないた
め、非金属介在物の組成に及ぼす悪影響が小さく、また
製造コストを低く抑えることもできる。Refractory of refining vessel: MgO content of 50 to
When a magcro-based refractory with a main component of Cr 2 O 3 of 85% by weight and a ladle refractory is used, CaO in the slag is used.
If the / SiO 2 ratio exceeds 1.9, the erosion of the refractory increases, and the MgO concentration in the slag increases, so that the MgO concentration in the nonmetallic inclusions increases. As a result, there is a high possibility that non-metallic inclusions will cause work cracks. In contrast, M
The gO content is 40 to 63% by weight and the remaining main component is CaO
Dolomite refractory is CaO / Si in slag
The increase in the O 2 ratio does not accelerate the erosion of the refractory, so that the adverse effect on the composition of the nonmetallic inclusions is small, and the production cost can be suppressed.
【００１３】[0013]
【実施例】実施例１：表１に示した成分組成をもつフェ
ライト系ステンレス鋼を７０トン電気炉で溶解し、転炉
処理，ＶＯＤ精錬，連鋳，熱延，酸洗，冷延を経て、種
々の非金属介在物が分散した板厚０．５ｍｍのステンレ
ス鋼薄板を製造した。このステンレス鋼薄板に１段絞り
で絞り比２の絞り加工を施し、非金属介在物の組成及び
加工割れの発生有無に及ぼす精錬時のスラグ組成の影響
を調査した。EXAMPLES Example 1 A ferritic stainless steel having the composition shown in Table 1 was melted in a 70-ton electric furnace and subjected to converter treatment, VOD refining, continuous casting, hot rolling, pickling, and cold rolling. A stainless steel thin plate having a thickness of 0.5 mm in which various nonmetallic inclusions were dispersed was manufactured. This stainless steel sheet was subjected to drawing at a drawing ratio of 2 using a single-step drawing, and the effects of slag composition during refining on the composition of nonmetallic inclusions and the presence or absence of processing cracks were investigated.
【００１４】 [0014]
【００１５】図１〜３の調査結果にみられるように、精
錬時のスラグに含まれるＡｌ2 Ｏ3の濃度及びＣａＯ／
ＳｉＯ2 の重量比に応じて絞り加工時の加工割れが異な
っていた。なお、図１〜３では、非金属介在物に含まれ
る各成分の濃度を縦軸に示し、加工割れが発生した場合
を白抜き記号で、加工割れが発生しなかった場合を中実
記号で示した。図１，２から、スラグのＡｌ2 Ｏ3 濃度
が８．０重量％以下でＣａＯ／ＳｉＯ 2 比が１．４より
低い場合、ＭｎＯ−ＳｉＯ2 系の非金属介在物が生成し
ていることが判る。生成した非金属介在物は、Ａｌ2 Ｏ
3 （丸印）やＭｇＯ（三角印）を僅かに含む程度であっ
たが、約１３〜１８重量％のＣｒ2 Ｏ3 （四角印）を含
んでいた。このことから、スラグのＡｌ2 Ｏ3 濃度が
８．０重量％以下でＣａＯ／ＳｉＯ2 比が１．４より低
いと、Ｃｒ2 Ｏ3 の還元が十分に進行せず、加工割れの
原因となる非金属介在物が生成するものと推察される。As can be seen from the survey results in FIGS.
Al contained in slag during smeltingTwo OThreeConcentration and CaO /
SiOTwo Processing cracks during drawing according to the weight ratio of
I was In addition, in FIGS. 1-3, it is included in nonmetallic inclusions.
Vertical axis shows the concentration of each component
Is a white symbol, and if no machining cracking occurs, it is solid
Indicated by symbols. From Figures 1 and 2, the slag AlTwo OThree concentration
Is less than 8.0% by weight and CaO / SiO Two Ratios from 1.4
If low, MnO-SiOTwo Of non-metallic inclusions
You can see that The generated nonmetallic inclusions are AlTwo O
Three (Circle) and MgO (triangle).
However, about 13 to 18% by weight of CrTwo OThree (Square mark)
I was out. From this, the slag AlTwo OThree Concentration
CaO / SiO at 8.0% by weight or lessTwo Ratio is lower than 1.4
I, CrTwo OThree Reduction does not proceed sufficiently,
It is presumed that nonmetallic inclusions causing the formation are generated.
【００１６】Ｃｒ2 Ｏ3 の濃度は、ＣａＯ／ＳｉＯ2 比
が大きくなるに従って減少しており、ＣａＯ／ＳｉＯ2
比が２．４を超える条件下では非金属介在物にほとんど
Ｃｒ 2 Ｏ3 が含まれていなかった。しかし、非金属介在
物中のＡｌ2 Ｏ3 濃度が約４０〜７０重量％，ＭｇＯ濃
度が約１０〜３０重量％になっていた。特にＣａＯ／Ｓ
ｉＯ2 比が２．６を超えるようなスラグ組成では、硬質
のスピネル型非金属介在物が生成し易くなる。また、ス
ラグ中のＡｌ2 Ｏ3 濃度が９．５重量％を超えると、図
３に示すようにＣａＯ／ＳｉＯ2 比に拘らず、全ての条
件下で加工割れの原因となる非金属介在物が生成してい
た。CrTwo OThree Is CaO / SiOTwo ratio
Decreases as Ca increases, and CaO / SiOTwo
When the ratio exceeds 2.4, almost no nonmetallic inclusions
Cr Two OThree Was not included. But non-metallic intervention
Al in materialTwo OThree Concentration is about 40-70% by weight, MgO concentration
The degree was about 10 to 30% by weight. Especially CaO / S
iOTwo In a slag composition having a ratio exceeding 2.6, hard
, A spinel-type nonmetallic inclusion is easily formed. Also,
Al in the rugTwo OThree If the concentration exceeds 9.5% by weight,
As shown in FIG.Two All articles, regardless of ratio
Non-metallic inclusions that cause work cracking
Was.
【００１７】これに対し、スラグ中のＡｌ2 Ｏ3 濃度を
８．０重量％以下に規制し、ＣａＯ／ＳｉＯ2 比を１．
４〜２．４の範囲に維持して精錬すると、生成した非金
属介在物は、Ｃｒ2 Ｏ3 濃度１０重量％以下，Ａｌ2 Ｏ
3 濃度４０重量％以下，ＭｇＯ濃度１０重量％以下の組
成をもつＭｎＯ−ＳｉＯ2 系非金属介在物となった。こ
の非金属介在物は、熱間加工時に粘性変形し、冷間加工
時に微細分散する特性をもっている。そのため、図１，
２に中実記号で示すように、加工割れの発生がないステ
ンレス鋼板が得られた。On the other hand, the Al 2 O 3 concentration in the slag is regulated to 8.0% by weight or less, and the CaO / SiO 2 ratio is set to 1.0% by weight.
When refined while maintaining the range of 4 to 2.4, the generated nonmetallic inclusions have a Cr 2 O 3 concentration of 10% by weight or less and an Al 2 O
3 MnO—SiO 2 -based nonmetallic inclusions having a composition with a concentration of 40% by weight or less and a MgO concentration of 10% by weight or less. This nonmetallic inclusion has the property of viscous deformation during hot working and fine dispersion during cold working. Therefore, FIG.
As shown by the solid symbols in FIG. 2, a stainless steel sheet free from cracks was obtained.
【００１８】次いで、非金属介在物の組成に及ぼすメタ
ル組成の影響を調査した。非金属介在物組成に影響を及
ぼすメタル組成としては精錬時に添加する脱酸剤が挙げ
られ、脱酸剤としてはＳｉ，Ａｌが使用されることか
ら、非金属介在物組成に及ぼすＳｉ濃度及びＡｌ濃度の
影響を調べた。図４の調査結果にみられるように、Ａｌ
濃度が０．００３重量％より高い場合、Ｓｉ濃度の如何
に拘らず加工割れや表面疵の発生が検出された。そこ
で、Ａｌ濃度を０．００３重量％以下としてＳｉ濃度を
変化させたところ、Ｓｉ／Ａｌの重量比が１００以上に
なると加工割れや表面疵が発生しなくなった。更に、ス
テンレス鋼の精錬に使用される耐火物の組成が非金属介
在物に及ぼす影響を調査した。ＭｇＯ含有量が４０〜６
３％で残部の主成分がＣａＯであるドロマイト系耐火
物、ＭｇＯ含有量が５０〜８５重量％で残部の主成分が
Ｃｒ2 Ｏ 3 であり、その他にＳｉＯ2 やＡｌ2 Ｏ3 を含
むＭｇＯ−Ｃｒ2 Ｏ3 系耐火物（マグクロ系）を使用
し、精錬後の非金属介在物組成を比較調査した。Next, the influence of meta on the composition of nonmetallic inclusions
The effect of the composition of the metal was investigated. Affects the composition of non-metallic inclusions
The deoxidizing agent added during refining is used as a metal composition
That Si and Al are used as deoxidizers
Et al. Show that the influence of Si concentration and Al concentration on the composition of nonmetallic inclusions
The effects were investigated. As can be seen from the survey results in FIG.
If the concentration is higher than 0.003% by weight,
Regardless, the occurrence of processing cracks and surface flaws was detected. There
Then, the Al concentration is made 0.003% by weight or less and the Si concentration is made
When changed, the weight ratio of Si / Al becomes 100 or more
Then, no processing cracks or surface flaws occurred. In addition,
The composition of refractories used for refining stainless steel is
The effects on living things were investigated. MgO content of 40-6
Dolomite refractory with 3% CaO as the balance
Substance, MgO content is 50-85% by weight and the remaining main component is
CrTwo O Three And other than SiOTwo And AlTwo OThree Including
MgO-CrTwo OThree Uses refractory (magcro)
Then, the composition of nonmetallic inclusions after refining was compared and investigated.
【００１９】図５の調査結果にみられるように、マグク
ロ系耐火物ではＣａＯ／ＳｉＯ2 比が大きくなると溶損
量が増加する傾向を示し、ＣａＯ／ＳｉＯ2 比が１．９
を超える付近で溶損量が増大した。溶損量の増加に伴っ
て、非金属介在物中のＭｇＯ濃度も増加する傾向を示
し、ＣａＯ／ＳｉＯ2 比２．０以上で非金属介在物中の
ＭｇＯ濃度が１０重量％を超えるようになった。ＭｇＯ
濃度の上昇は、溶損した耐火物中のＭｇＯが還元されて
鋼中Ｍｇとなり、非金属介在物中の酸素と結び付くこと
に起因するものと推察される。As can be seen from the investigation results in FIG. 5, the magcro-based refractory tends to increase the amount of erosion when the CaO / SiO 2 ratio is increased, and the CaO / SiO 2 ratio is 1.9.
The erosion amount increased in the vicinity of exceeding. As the amount of erosion increases, the MgO concentration in the nonmetallic inclusions also tends to increase, such that the MgO concentration in the nonmetallic inclusions exceeds 10% by weight at a CaO / SiO 2 ratio of 2.0 or more. became. MgO
It is presumed that the increase in the concentration is caused by the reduction of MgO in the eroded refractory to form Mg in the steel and binding with oxygen in the nonmetallic inclusions.
【００２０】他方、ドロマイト系耐火物を使用した場
合、ＣａＯ／ＳｉＯ2 比が高くなっても精錬時の耐火物
の溶損が少ないため、非金属介在物中のＭｇＯ濃度が７
重量％を超えることはなかった。ＭｇＯ濃度の上昇が抑
制される理由は明らかでないが、耐火物成分であるＣａ
Ｏ−ＭｇＯがスラグ成分であるＣａＯ−ＳｉＯ2 と反応
して耐火物表層部のＣａＯ／ＳｉＯ2 比が高くなり、結
果として耐火物表層部が高融点の耐火物でコーティング
された状態になることに起因するものと推察される。し
かも、ドロマイト系耐火物は、マグクロ系耐火物に比較
して安価であるため、製造コストの面でも有利である。On the other hand, when a dolomite-based refractory is used, even if the CaO / SiO 2 ratio is high, the refractory hardly dissolves during refining, so that the MgO concentration in the nonmetallic inclusion is 7%.
% By weight. It is not clear why the increase in the MgO concentration is suppressed, but the refractory component Ca
O-MgO is higher CaO / SiO 2 ratio reacts with CaO-SiO 2 is a slag component refractory surface portion, the result that the refractory surface layer portion is in a state coated with refractory material of a refractory as It is presumed to be due to In addition, dolomite-based refractories are inexpensive compared to magcro-based refractories, and are therefore advantageous in terms of manufacturing costs.
【００２１】実施例２：フェライト系ステンレス鋼を７
０トン電気炉で溶解し、転炉で製錬し、ＶＯＤ鍋に注湯
した。取鍋としては、ＭｇＯ：４０〜６３重量％，残部
ＣａＯのドロマイト系耐火物をライニングした取鍋、Ｍ
ｇＯ：５０〜８５重量％，Ｃｒ2 Ｏ3 ：７〜３０重量％
でその他にＳｉＯ2 ，Ａｌ2 Ｏ3 を含むマグクロ系耐火
物をライニングした取鍋を使用した。取鍋に収容した溶
鋼をＶＯＤ炉で精錬し、メタル組成及びスラグ組成を変
化させた。このようにして製造されたフェライト系ステ
ンレス鋼の成分・組成を表２に示す。Example 2: Ferritic stainless steel was added to 7
It was melted in a 0-ton electric furnace, smelted in a converter, and poured into a VOD pan. As a ladle, a ladle lined with dolomite-based refractories of MgO: 40 to 63% by weight and the balance CaO, M
It goes: 50~85 weight%, Cr 2 O 3: 7~30 weight%
In addition, a ladle lined with a refractory magcro containing SiO 2 and Al 2 O 3 was used. Molten steel stored in a ladle was refined in a VOD furnace to change the metal composition and slag composition. Table 2 shows the components and compositions of the ferritic stainless steel thus manufactured.
【００２２】 [0022]
【００２３】精錬後の溶鋼を厚み２００ｍｍ，幅１ｍの
スラブに連続鋳造した。得られたスラブを１２００℃で
熱間圧延した後、板厚０．５ｍｍの薄板に仕上げ、更に
１段絞りで絞り比２の加工を施した。加工された鋼板を
観察し、加工割れの発生有無を調査した。そして、ＶＯ
Ｄ精錬後のスラグ組成，薄板のメタル組成が絞り加工後
の加工割れに及ぼす影響を調査した。表３の調査結果に
みられるように、本発明に従った条件下で製造されたフ
ェライト系ステンレス鋼は、何れも加工割れが検出され
ず、非金属介在物が無害化されていることが判る。これ
に対し、スラグ組成やメタル組成が本発明で規定した範
囲を外れる比較例のフェライト系ステンレス鋼では、有
害な非金属介在物が分散しており、絞り加工後に加工割
れが発生していた。The molten steel after refining was continuously cast into a slab having a thickness of 200 mm and a width of 1 m. The obtained slab was hot-rolled at 1200 ° C., finished into a thin plate having a thickness of 0.5 mm, and further processed by a one-stage drawing at a drawing ratio of 2. The processed steel plate was observed to check for occurrence of processing cracks. And VO
The effects of the slag composition after D refining and the metal composition of the thin plate on the work cracking after drawing were investigated. As can be seen from the results of the investigation in Table 3, none of the ferritic stainless steels produced under the conditions according to the present invention detected any work cracks and the nonmetallic inclusions were rendered harmless. . On the other hand, in the ferritic stainless steel of the comparative example in which the slag composition and the metal composition were out of the ranges specified in the present invention, harmful nonmetallic inclusions were dispersed, and processing cracks occurred after drawing.
【００２４】 [0024]
【００２５】[0025]
【発明の効果】以上に説明したように、本発明のフェラ
イト系ステンレス鋼は、非金属介在物を熱間加工時に粘
性変形し、冷間加工時に微細分散するＭｎ−ＳｉＯ2 系
に調整しているため、加工割れの起点となる非金属介在
物がなく、加工割れ感受性の低い材料であり、過酷な加
工に供される各種機能材料として使用される。また、メ
タル組成，精錬後のスラグ組成，耐火物組成等を調整す
ることにより非金属介在物が組成制御されるため、製造
自体も容易である。As described above, the ferritic stainless steel of the present invention is adjusted to a Mn-SiO 2 system in which nonmetallic inclusions are viscously deformed during hot working and finely dispersed during cold working. Therefore, it has no non-metallic inclusions serving as starting points for processing cracks, is a material having low susceptibility to processing cracks, and is used as various functional materials subjected to severe processing. Further, since the composition of the nonmetallic inclusions is controlled by adjusting the metal composition, the slag composition after refining, the refractory composition, and the like, the production itself is easy.
【図１】 スラグのＡｌ2 Ｏ3 濃度３．２重量％，メタ
ルのＳｉ／Ａｌ比５００の条件下でスラグのＣａＯ／Ｓ
ｉＯ2 比が非金属介在物の組成及び加工割れに及ぼす影
響を示したグラフFIG. 1 CaO / S of slag under conditions of Al 2 O 3 concentration of slag of 3.2% by weight and metal Si / Al ratio of 500
Graph showing the effect of iO 2 ratio on the composition of nonmetallic inclusions and work cracking
【図２】 スラグのＡｌ2 Ｏ3 濃度８重量％，メタルの
Ｓｉ／Ａｌ比３００の条件下でスラグのＣａＯ／ＳｉＯ
2 比が非金属介在物の組成及び加工割れに及ぼす影響を
示したグラフFIG. 2 CaO / SiO of slag under the conditions of Al 2 O 3 concentration of slag of 8% by weight and Si / Al ratio of metal of 300.
Graph showing the effect of the 2 ratio on the composition and work cracking of nonmetallic inclusions
【図３】 スラグのＡｌ2 Ｏ3 濃度９重量％，メタルの
Ｓｉ／Ａｌ比３００の条件下でスラグのＣａＯ／ＳｉＯ
2 比が非金属介在物の組成及び加工割れに及ぼす影響を
示したグラフ[FIG. 3] CaO / SiO of slag under the condition of Al 2 O 3 concentration of slag of 9% by weight and metal Si / Al ratio of 300
Graph showing the effect of the 2 ratio on the composition and work cracking of nonmetallic inclusions
【図４】 メタル中のＳｉ濃度及びＡｌ濃度が加工割れ
に及ぼす影響を示したグラフFIG. 4 is a graph showing the effect of Si concentration and Al concentration in metal on work cracking.
【図５】 ＣａＯ／ＳｉＯ2 比が耐火物の溶損及び非金
属介在物中のＭｇＯ濃度に及ぼす影響を示したグラフFIG. 5 is a graph showing the effect of the CaO / SiO 2 ratio on the erosion of refractories and the MgO concentration in nonmetallic inclusions.
Claims (2)
１．０重量％，Ｍｎ：０．１〜１．０重量％，Ｃｒ：１
０〜３２重量％，Ａｌ：０．００３重量％以下，残部が
実質的にＦｅの組成を持ち、Ｓｉ／Ａｌの重量比が１０
０以上で、非金属介在物の組成がＭｎＯ−ＳｉＯ2 を主
成分とし、ＭｇＯ：７重量％以下，Ａｌ2 Ｏ3 ：３５重
量％以下，Ｃｒ2 Ｏ3 ：１０重量％以下である加工割れ
感受性の低いフェライト系ステンレス鋼。C: 0.1% by weight or less, Si: 0.1 to
1.0% by weight, Mn: 0.1 to 1.0% by weight, Cr: 1
0 to 32% by weight, Al: 0.003% by weight or less, the balance substantially has a Fe composition, and the weight ratio of Si / Al is 10%.
Greater than 0, the composition of nonmetallic inclusions as a main component MnO-SiO 2, MgO: 7 wt% or less, Al 2 O 3: 35 wt% or less, Cr 2 O 3: machining cracks 10 wt% or less Low sensitivity ferritic stainless steel.
錬容器にステンレス溶鋼を装入し、精錬終了時にＣａＯ
／ＳｉＯ2 の重量比が１．４〜２．４，Ａｌ 2 Ｏ3 濃度
が８重量％以下の組成となるスラグを用いて請求項１記
載の組成に溶製することを特徴とする加工割れ感受性の
低いフェライト系ステンレス鋼の製造方法。2. A refined lining of dolomite-based refractories.
A molten stainless steel is charged into a smelting vessel, and CaO
/ SiOTwo Weight ratio of 1.4 to 2.4, Al Two OThree concentration
Using slag having a composition of 8% by weight or less.
Susceptibility to work cracking, characterized by being melted to the specified composition
Manufacturing method of low ferritic stainless steel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08099298A JP3953626B2 (en) | 1998-03-27 | 1998-03-27 | Ferritic stainless steel excellent in drawing workability and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08099298A JP3953626B2 (en) | 1998-03-27 | 1998-03-27 | Ferritic stainless steel excellent in drawing workability and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11279711A true JPH11279711A (en) | 1999-10-12 |
| JP3953626B2 JP3953626B2 (en) | 2007-08-08 |
Family
ID=13734007
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08099298A Expired - Fee Related JP3953626B2 (en) | 1998-03-27 | 1998-03-27 | Ferritic stainless steel excellent in drawing workability and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3953626B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003089853A (en) * | 2001-09-14 | 2003-03-28 | Nisshin Steel Co Ltd | HIGH PURITY Fe-Cr ALLOY HAVING EXCELLENT FORMING WORKABILITY |
| KR100948921B1 (en) * | 2003-04-16 | 2010-03-23 | 주식회사 포스코 | Refining method of ferrite stainless steel |
| JP2011214079A (en) * | 2010-03-31 | 2011-10-27 | Nisshin Steel Co Ltd | Ferritic stainless steel sheet superior in cleanability and manufacturing method therefor |
-
1998
- 1998-03-27 JP JP08099298A patent/JP3953626B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003089853A (en) * | 2001-09-14 | 2003-03-28 | Nisshin Steel Co Ltd | HIGH PURITY Fe-Cr ALLOY HAVING EXCELLENT FORMING WORKABILITY |
| KR100948921B1 (en) * | 2003-04-16 | 2010-03-23 | 주식회사 포스코 | Refining method of ferrite stainless steel |
| JP2011214079A (en) * | 2010-03-31 | 2011-10-27 | Nisshin Steel Co Ltd | Ferritic stainless steel sheet superior in cleanability and manufacturing method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3953626B2 (en) | 2007-08-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2018066182A1 (en) | Fe-Cr-Ni ALLOY AND METHOD FOR PRODUCING SAME | |
| JP6869142B2 (en) | Stainless steel sheet and its manufacturing method | |
| JP6990337B1 (en) | Ni-based alloy with excellent surface properties and its manufacturing method | |
| JP2008240137A (en) | Method for smelting ti-containing extra-low carbon steel, and method for producing ti-containing extra-low carbon steel slab | |
| JP6937190B2 (en) | Ni-Cr-Mo-Nb alloy and its manufacturing method | |
| JP6603033B2 (en) | High Mn content Fe-Cr-Ni alloy and method for producing the same | |
| JP3865853B2 (en) | Austenitic stainless steel with low work cracking susceptibility and method for producing the same | |
| TW201942363A (en) | Ferritic stainless steel with excellent ridging resistance | |
| CN113046616B (en) | Stainless steel excellent in surface properties and method for producing same | |
| JP6903182B1 (en) | Ni-Cr-Al-Fe alloy with excellent surface properties and its manufacturing method | |
| JP5853281B2 (en) | Austenitic stainless steel sheet with excellent surface gloss | |
| JP5212581B1 (en) | Method for producing high Si austenitic stainless steel | |
| JP7187213B2 (en) | Stainless steel plate with excellent surface properties and its manufacturing method | |
| KR100886046B1 (en) | Method for producing extremely low carbon steel sheet and extremely low carbon cast piece having excellent surface characteristics, workability and formability | |
| JPH11279711A (en) | Ferritic stainless steel low in working crack sensitivity and its production | |
| JPH0362769B2 (en) | ||
| JPS6263650A (en) | Bearing steel and its production | |
| JP2023057398A (en) | Nickel alloy excellent in surface quality and production method thereof | |
| JP3416858B2 (en) | Stainless steel manufacturing method | |
| JP2004043838A (en) | Method for melting ferritic stainless steel with excellent ridging resistance/workability, and steel sheet | |
| TWI764512B (en) | Fertilizer iron series stainless steel | |
| JP7369266B1 (en) | Fe-Cr-Ni alloy with excellent surface properties and its manufacturing method | |
| JPH0469207B2 (en) | ||
| JP2000129402A (en) | Stainless steel slab excellent in workability and its production | |
| JP2547139B2 (en) | Method for controlling composition of non-metallic inclusions in steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Effective date: 20050303 Free format text: JAPANESE INTERMEDIATE CODE: A621 |
|
| A977 | Report on retrieval |
Effective date: 20070104 Free format text: JAPANESE INTERMEDIATE CODE: A971007 |
|
| A131 | Notification of reasons for refusal |
Effective date: 20070123 Free format text: JAPANESE INTERMEDIATE CODE: A131 |
|
| RD02 | Notification of acceptance of power of attorney |
Effective date: 20070228 Free format text: JAPANESE INTERMEDIATE CODE: A7422 |
|
| RD04 | Notification of resignation of power of attorney |
Effective date: 20070301 Free format text: JAPANESE INTERMEDIATE CODE: A7424 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070313 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070424 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070425 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100511 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110511 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 4 Free format text: PAYMENT UNTIL: 20110511 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 5 Free format text: PAYMENT UNTIL: 20120511 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 6 Free format text: PAYMENT UNTIL: 20130511 |
|
| LAPS | Cancellation because of no payment of annual fees |