US20090223603A1 - Method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it - Google Patents

Method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it Download PDF

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Publication number
US20090223603A1
US20090223603A1 US12/158,515 US15851506A US2009223603A1 US 20090223603 A1 US20090223603 A1 US 20090223603A1 US 15851506 A US15851506 A US 15851506A US 2009223603 A1 US2009223603 A1 US 2009223603A1
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United States
Prior art keywords
molten steel
concentration
ferritic stainless
stainless steel
grain structures
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Abandoned
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US12/158,515
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English (en)
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Joo-Hyun Park
Hyo-Seok Song
Hee-Ho Lee
Dong-Sik Kim
Kyo-Soo Lee
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Posco Holdings Inc
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Individual
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Assigned to POSCO reassignment POSCO ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KIM, DONG-SIK, Lee, Hee-ho, LEE, KYO-SOO, PARK, JOO-HYUN, SONG, HYO-SEOK
Publication of US20090223603A1 publication Critical patent/US20090223603A1/en
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52—Manufacture of steel in electric furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/068—Decarburising
    • C21C7/0685—Decarburising of stainless steel
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0006—Adding metallic additives
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum

Definitions

  • the present invention relates to a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it, and more specifically to a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it which control concentration of alumina inclusions in molten steel to maximize an available TiN generation effect serving as a non-uniform nucleating site of ferrite when solidifying it, thereby improving equiaxed crystal ratio.
  • TiN is formed by the following equation from a steel making process to a continuous casting process, wherein when its size and distribution are proper, it serves as a non-uniform nucleating site of ferrite in solidifying molten steel, thereby obtaining equiaxed grain structures.
  • U.S. Pat. No. 5,868,875 has described that Ti concentration satisfies (% Ti/48)/[% C/120+(% N/14)]>1.5, in making Ti deoxidation for molten steel with Cr: 8 ⁇ 25%, Mn: 0.1 ⁇ 1.5% Mn, Si: 1.5% or less, N: 0.05% or less, C: 0.08% or less, and Al: 0.01% or less.
  • European Patent No. 924313 has described that equiaxed crystal ratio in slab of 50% or more can be assured when satisfying [% Ti] ⁇ % N] ⁇ 0.14 ⁇ [% Al] among the concentrations of Ti, Al and N.
  • European Patent No. 1491646 has described that slabs with equiaxed grain structures can be manufactured by adding Mg of 2 ⁇ 50 ppm to the molten steel consisting of Cr: 10 ⁇ 20%, C: 0.001 ⁇ 0.01%, Si: 0.01 ⁇ 0.3%, Mn: 0.01 ⁇ 0.3%, N: 0.001 ⁇ 0.02%, and Ti: 0.05 ⁇ 0.3%.
  • Japanese Patent No. 2000-1602999 has described that when making vacuum oxygen decarburization refining, equiaxed crystal ratio in slab of 60% or more can be obtained by injecting CaO and Al to make basicity of CaO—Al 2 O 3 -based slag to be the range of 0.7 ⁇ 2.5 and making molten steel stirring for 5 minutes or more, and adding Ti to allow only TiN nitride to have area ratio of 0.01% or more.
  • the present invention is proposed to solve the problems in a prior art as described above. It is an object of the present invention to provide a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it, which control concentration of the alumina inclusions in molten steel using composite deoxidation of Si/M/AlTi in vacuum oxygen decarburization refining process to maximize an available TiN generation effect serving as a non-uniform nucleating site of ferrite when solidifying it, thereby manufacturing ferritic stainless steel slab with high equiaxed crystal ratio and excellent formability, that is, low ridging defect.
  • a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it according to the present invention as described above precisely controls components of molten steel, such as Si and Mn, etc., and concentration of alumina inclusions to effectively generate available TiN so that it can manufacture ferritic stainless steel slabs with equiaxed grain structures and high equiaxed crystal ratio while improving operating stability, thereby obtaining ferritic stainless steel slabs with equiaxed grain structures having excellent formability, that is, low ridging defect.
  • FIG. 1 is a flow chart illustrating a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures according to a preferred embodiment of the present invention
  • FIG. 2 is a graph illustrating a change in equiaxed crystal ratio in slabs according to the control of alumina inclusion concentration
  • FIG. 3 is a graph illustrating the result of FIG. 2 as distributed data
  • FIG. 4 is a graph illustrating the decrease of Al 2 O 3 and TiOx inclusions by a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures according to a preferred embodiment of the present invention, compared to the conventional example;
  • FIG. 5 is an electronmicroscope photograph illustrating the form of oxide-TiN composite inclusions distributed inside slabs with equiaxed grain structures by a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures according to a preferred embodiment of the present invention, compared to the conventional example.
  • a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures comprising the steps of: performing oxygen decarburization reaction by blowing oxygen from the upper part of the molten steel in a vacuum oxygen decarburization ladle; injecting Al in the molten steel to which the oxygen decarburization reaction is made for Cr 2 O 3 reduction; making composite deoxidation by injecting deoxidizer in the molten steel into which the Al is injected for the Cr 2 O 3 reduction; making alloying process by injecting alloying metal in the molten steel; first judging for judging whether Al concentration is in the range of a setting value by analyzing the Al concentration in the molten steel; if the Al concentration satisfies the setting value, stirring it using inert gas and second judging for judging whether alumina inclusion concentration in the final molten steel corresponds to a target value; and if the alumina inclusion concentration satisfies the target value, continuously casting the molten steel.
  • the deoxidizer may be Si and Mn and in the allyoing step, the alloying metal may be Ti with 0.2-0.4% by mass.
  • the alumina inclusion concentration in the molten steel satisfies the following condition.
  • the component of the molten steel satisfies the following condition.
  • % is % by mass.
  • the final composition of a refined slag in the vacuum oxygen decarburization refining ladle satisfies the following condition.
  • % is % by mass.
  • the molten steel is 80 ⁇ 85 ton.
  • the setting value of Al concentration in the first judging step is 0.05 ⁇ 0.12% by mass, wherein if the Al concentration is less than 0.05% by mass, it further comprises the step of additionally injecting Al of 30 ⁇ 40 kg relative to the molten steel of 80 ⁇ 85 ton and if the Al concentration is 0.12% by mass or more, it further comprises the step of additionally injecting quicklime of 250 ⁇ 300 kg relative to the molten steel of 80 ⁇ 85 ton.
  • the target value of the alumina inclusion concentration in the second judging is 70 ppm or less.
  • the ferritic stainless steel slabs with equiaxed grain structure of the present invention are manufactured according to a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures of the present invention, wherein it is characterized in that the alumina inclusion concentration is 70 ppm or less and equiaxed crystal ratio in slabs is 40% or more.
  • FIG. 1 a flow chart illustrating a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures according to a preferred embodiment of the present invention.
  • a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures comprises the steps of: performing (S 10 ) oxygen decarburization reaction by blowing oxygen from the upper part of the molten steel in a vacuum oxygen decarburization ladle; injecting Al in the molten steel to which the oxygen decarburization reaction is made for Cr 2 O 3 reduction (S 20 ); making composite deoxidating (S 30 ) by injecting deoxidizer in the molten steel into which the Al is injected for the Cr 2 O 3 reduction; making alloying process (S 40 ) by injecting alloying metal in the molten steel; first judging (S 50 ) for judging whether Al concentration is in the range of a setting value by analyzing the Al concentration in the molten steel; if the Al concentration satisfies the setting value, stirring (S 60 ) it using inert gas and second judging (S 70 ) for judging whether the alumina inclusion concentration in the final molten steel corresponds to
  • the setting value of the concentration of Al in the first judging step (S 50 ) is 0.05 ⁇ 0.12% by mass (S 51 ), wherein it is preferable that if the Al concentration is less than 0.05% by mass (S 52 ), it further comprises the step of injecting (S 54 ) Al and if the Al concentration is 0.12% by mass or more, injecting quicklime (S 56 ).
  • the deoxidizer is Si and Mn and in the allyoing step (S 40 ), the alloying metal is Ti.
  • FIG. 2 is a graph illustrating a change in equiaxed crystal ratio in slabs according to the control of the alumina inclusion concentration
  • FIG. 3 is a graph illustrating the result of FIG. 2 as distributed data.
  • the equiaxed crystal ration in slabs is increased as the alumina inclusion concentration in the molten steel is decreased.
  • a proper concentration of the alumina inclusions can be set to be less than 70 ppm.
  • the slabs with equiaxed crystal ratio of 40 ⁇ 100% can be obtained.
  • the alumina inclusion concentration exceeds 70 ppm, the creation of available TiN is suppressed so that it is impossible to assure a targeted equiaxed crystal ratio.
  • the step of decreasing Cr 2 O 3 by injecting Al controls a targeted composition by making composite deoxidation by injecting Si and Mn and then injecting Ti.
  • the Al concentration is primarily analyzed. If the primary Al concentration is too low, Al is further injected and if too high, quicklime is further injected. Subsequently, they are stirred using inert gas in the bottom of the ladle so that the alumina inclusion concentration in the final molten steel is controlled to conform to the targeted range to make a continuous casting.
  • the present invention can obtain higher equiaxed crystal ratio of 40% or more, compared with the example of the prior art.
  • TiN is formed in the molten steel by the reaction of the equation 1; however, a point in time forming it varies depending on the composition and temperature of the molten steel. If TiN is formed in the ladle or a tundish prior to solidifying the molten steel, TiN may be generated through a uniform nucleating and growing by the reaction of Ti atom with N atom, however, it is advantageous that the nucleating is made at the third interface in terms of thermodynamics, for example, at the interface of oxidation-inclusions/molten steel, etc.
  • l oxide and l TiN respectively, means lattice constants of the crystals of the oxidation-inclusions and TiN. It means that it is difficult to serve as the non-uniform nucleating site as ⁇ between two substances becomes large.
  • ⁇ Al203-TiN between Al 2 O 3 of a hexagonal structure and TiN of a face-centered cubic (FCC) structure is approximately 0.1
  • ⁇ MgO(or spinel)-TiN between MgO or MgAl 2 O 3 spinel of the same face-centered cubic and the TiN is approximately 0.0002.
  • the TiN nucleating is degraded so that upon solidifying, it may be a factor to cause the non-uniform nucleating of ferrite to degrade.
  • FIG. 4 is a graph illustrating the decrease of Al 2 O 3 and TiOx inclusions by a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures according to a preferred embodiment of the present invention, compared to the conventional example.
  • the [Al] concentration is primarily analyzed in the molten steel at a point in time elapsing about 5 minutes after the injection.
  • the Al concentration is less than 0.05%, if Al less than 30 kg is injected, its adding effect is insignificant relative to the molten steel of 80 ⁇ 85 ton so that effective Cr 2 O 3 reduction cannot be achieved, and if Al exceeding 40 kg is injected, the Al concentration may exceed 0.12%. Accordingly, it is preferable that the amount of Al added is 30 ⁇ 40 kg.
  • the amount of quicklime added is 250 ⁇ 300 kg.
  • the final composition of refined slag in the vacuum oxygen decarburization ladle is 1.1 ⁇ (% CaO)/(% Al 2 O 3 ) ⁇ 1.4 and 4 ⁇ (% TiO 2 )/(% SiO 2 ) ⁇ 6.
  • the ladle After the ladle process, the ladle is transferred to a continuous casting process.
  • the component of the molten steel in the final tundish is analyzed as in the following table 3.
  • [Al alumina ] concentration existing as alumina is 40 ppm. It may be appreciated that the concentration is within the range of the present invention.
  • N concentration in the molten steel is about 110 ppm and reacts with 0.30% [Ti] to contribute the generation of available TiN as shown in FIG. 5 , thereby obtain slabs with equiaxed grain structures.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Continuous Casting (AREA)
US12/158,515 2005-12-28 2006-11-09 Method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it Abandoned US20090223603A1 (en)

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KR1020050131297A KR100729934B1 (ko) 2005-12-28 2005-12-28 응고조직이 미세한 페라이트계 스테인리스강 제조방법 및이로써 제조된 페라이트계 스테인리스강
KR10-2005-0131297 2005-12-28
PCT/KR2006/004673 WO2007074970A1 (en) 2005-12-28 2006-11-09 Method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it

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US (1) US20090223603A1 (de)
EP (1) EP1974063A4 (de)
JP (1) JP5221379B2 (de)
KR (1) KR100729934B1 (de)
CN (1) CN101351565B (de)
WO (1) WO2007074970A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016168827A1 (en) 2015-04-17 2016-10-20 The Curators Of The University Of Missouri Grain refinement in iron-based materials

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2047926A1 (de) * 2007-10-10 2009-04-15 Ugine & Alz France Verfahren zur Herstellung von rostfreiem Stahl mit feinen Carbonitriden, und Produkt, das mit diesem Verfahren hergestellt wird
KR100922059B1 (ko) * 2007-12-20 2009-10-16 주식회사 포스코 티타늄 첨가된 고크롬 스테인리스강의 정련방법
CN102199688B (zh) * 2010-03-25 2013-02-06 宝山钢铁股份有限公司 一种高效精炼超纯铁素体不锈钢的方法
TWI412597B (zh) * 2010-05-28 2013-10-21 China Steel Corp Bearing steel refining method for improving fatigue life
CA2819997C (en) 2010-11-05 2019-06-25 Kyushu University Preventive or therapeutic agent for pain associated with herpes zoster in acute phase
KR101198589B1 (ko) 2010-12-27 2012-11-06 주식회사 포스코 고크롬 페라이트 스테인리스강 정련방법 및 정련장치
JP5687590B2 (ja) * 2011-09-27 2015-03-18 日本冶金工業株式会社 ボロン含有ステンレス鋼の製造方法
JP6306353B2 (ja) * 2014-01-21 2018-04-04 Ｊｆｅスチール株式会社 フェライト系ステンレス冷延鋼板用スラブの製造方法およびフェライト系ステンレス冷延鋼板の製造方法
KR101898165B1 (ko) * 2016-12-06 2018-09-13 주식회사 포스코 주조조직이 미세한 페라이트계 스테인리스강의 제조방법
KR101896340B1 (ko) * 2017-06-01 2018-09-07 주식회사 포스코 용강 제조 방법
CN107574385B (zh) * 2017-08-28 2019-07-12 北京科技大学 一种提高双稳定铁素体不锈钢连铸坯等轴晶率的工艺方法
CN113502376A (zh) * 2021-06-18 2021-10-15 鞍钢联众(广州)不锈钢有限公司 一种改善含钛不锈钢钢坯次表皮夹杂的方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6559417B2 (en) * 2000-06-07 2003-05-06 Kiswell Ltd. Flux cored wire for arc-welding of austenitic stainless steel
US20060057414A1 (en) * 2004-09-15 2006-03-16 Hiroshi Matsuo Steel tube excellent in exfoliation resistance of scale on inner surface

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0949010A (ja) * 1995-08-09 1997-02-18 Nisshin Steel Co Ltd 等軸晶率の高いフエライト系ステンレス鋼連鋳スラブの製造方法
JP3288626B2 (ja) * 1997-03-21 2002-06-04 新日本製鐵株式会社 リジング特性に優れた高加工性フェライト系ステンレス鋼薄板及びその製造方法
TW496903B (en) * 1997-12-19 2002-08-01 Armco Inc Non-ridging ferritic chromium alloyed steel
JP2000073146A (ja) * 1998-08-27 2000-03-07 Nisshin Steel Co Ltd 耐リジング性に優れたフェライト系ステンレス鋼
JP2000160230A (ja) * 1998-11-20 2000-06-13 Nisshin Steel Co Ltd 耐リジング性に優れたフェライト系ステンレス鋼の製造方法
KR100706973B1 (ko) * 1999-04-08 2007-04-13 신닛뽄세이테쯔 카부시키카이샤 응고조직이 미세하고 가공특성이 우수한 주편과 이를이용하여 제조한 강재와 심리스 강관
JP2001049322A (ja) * 1999-08-05 2001-02-20 Nisshin Steel Co Ltd 耐リジング性に優れたフェライト系ステンレス鋼の製造方法
JP3668087B2 (ja) * 2000-02-03 2005-07-06 日本冶金工業株式会社 ステンレス鋼の高清浄化精錬方法
JP3624804B2 (ja) * 2000-07-14 2005-03-02 住友金属工業株式会社 耐リジング性フェライト系ステンレス鋼の製造方法
JP3733098B2 (ja) * 2002-10-23 2006-01-11 新日本製鐵株式会社 表面品質に優れた極低炭素または低炭素薄板用鋼板の溶製方法および連続鋳造鋳片

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6559417B2 (en) * 2000-06-07 2003-05-06 Kiswell Ltd. Flux cored wire for arc-welding of austenitic stainless steel
US20060057414A1 (en) * 2004-09-15 2006-03-16 Hiroshi Matsuo Steel tube excellent in exfoliation resistance of scale on inner surface

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016168827A1 (en) 2015-04-17 2016-10-20 The Curators Of The University Of Missouri Grain refinement in iron-based materials
EP3283608A4 (de) * 2015-04-17 2018-12-26 The Curators of the University of Missouri Kornfeinung bei materialien auf eisenbasis
US10465258B2 (en) 2015-04-17 2019-11-05 The Curators Of The University Of Missouri Grain refinement in iron-based materials

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CN101351565A (zh) 2009-01-21
KR100729934B1 (ko) 2007-06-18
JP5221379B2 (ja) 2013-06-26
EP1974063A1 (de) 2008-10-01
CN101351565B (zh) 2011-02-02
JP2009521599A (ja) 2009-06-04
EP1974063A4 (de) 2010-07-21

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