Connect public, paid and private patent data with Google Patents Public Datasets

Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Download PDF

Info

Publication number
USRE44153E1
Authority
US
Grant status
Grant
Patent type
Prior art keywords
sheet
lt
steel
coated
aluminum
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.)
Active
Application number
US13205126
Inventor
Jean-Pierre Laurent
Jean-Paul Hennechart
Dominique Spehner
Jacques Devroc
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ArcelorMittal Atlantique et Lorraine
ArcelorMittal SA
Original Assignee
ArcelorMittal Atlantique et Lorraine
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32Ferrous alloys, e.g. steel alloys containing chromium with boron
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHER TREATMENTS
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0278Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese

Abstract

Hot-rolled steel sheet which then can be cold-rolled, coated, the steel in the sheet having the following composition by weight:
    • 0.15%<carbon<0.5%
    • 0.5%<manganese<3%
    • 0.1%<silicon<0.5%
    • 0.01%<chromium<1%
    • titanium<0.2%
    • aluminum<0.1%
    • phosphorus<0.1%
    • sulfur<0.05%
    • 0.0005%<boron<0.08%, the remainder being iron and impurities inherent in processing, the sheet ensuring a very high mechanical resistance after thermal treatment and the aluminum-based coating ensuring a high resistance to corrosion.

Description

The invention relates to a coated, hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment.

In this technical area, the proposed solutions involving an increase in the mechanical characteristics are accomplished to the detriment of shaping properties. There is a solution consisting in separating the shaping properties and those required for use. The characteristics required for use are obtained through a thermal treatment subsequent to or concomitant with shaping. In this case, the proposed sheets are not delivered coated because of problems of holding power of the coating at the time of thermal treatment. Coating therefore is performed on finished castings, which requires a careful cleaning of the surfaces and the hollowed portions. In addition, the thermal treatment must be performed under a controlled atmosphere in order to prevent any decarbonization and oxidation of the metal in the sheet. Steel sheets for thermal treatment do not have any pre-coating which requires post-treatments of scouring, pickling and coating.

At the time of continuous coating of flat hot- and cold-rolled products, preliminary annealing and cooling preceding or following the zinc- or aluminum-based coating operation, are used only to bring the sheet to a temperature close to that of the bath or to restore the mechanical properties of the sheet degraded at the time of cold-rolling. These thermal cycles are chosen in terms of the composition of the steel so that no allotropic transformation takes place at the time of the thermal cycle, the objective being to obtain mechanical characteristics similar to those measured on the steel sheet delivered uncoated.

The purpose of the invention is to produce a hot- or cold-rolled steel sheet of a desired thickness, coated, and affording extensive shaping possibilities and which, after thermal treatment performed on the finished casting, makes it possible to obtain a mechanical resistance in excess of 1000 MPa, a substantial resistance to shocks, fatigue, abrasion and wear, while retaining a good resistance to corrosion as well as a good capacity for painting and gluing. It also is possible to carry out hot-shaping with hardening in the tool making it possible to obtain the same properties.

The subject of the invention is a hot-rolled steel sheet, which then can be cold-rolled, coated, the steel in the sheet having the following composition by weight:

    • 0.15%<carbon<0.5%
    • 0.5%<manganese<3%
    • 0.1% silicon<0.5%
    • 0.01%<chromium<1%
    • titanium<0.2%
    • aluminum<0.1%
    • phosphorus<0.01%
    • sulfur<0.05%
    • 0.0005%<boron<0.08%, the remainder being iron and impurities inherent in processing, the sheet ensuring a very high mechanical resistance after thermal treatment and the aluminum-based coating ensuring a high resistance to corrosion.

The other characteristics of the invention are:

    • the composition by weight of the sheet preferably is the following:
      • 0.20%<carbon<0.5%
      • 0.8%<manganese<1.5%
      • 0.1% silicon<0.35%
      • 0.01%<chromium<1%
      • titanium<0.1%
      • aluminum<0.1%
      • phosphorus<0.05%
      • sulfur<0.03%
      • 0.0005%<boron<0.01%, the remainder being iron and impurities inherent in processing.
    • in the composition by weight of the sheet, the titanium content with respect to the nitrogen content is in excess of 3.42, the boron no longer being able to be combined with the nitrogen.
    • the metal bath for the coating contains in its basic composition by weight, from 9% to 10% silicon, from 2% to 3.5% iron, the remainder being aluminum.
    • the metal bath for the coating contains in its basic composition by weight, from 2% to 4% iron, the remainder being aluminum.

The invention also concerns a process for producing a casting starting from the coated sheet in which, after shaping, the coating of the casting is subjected to an increase in temperature at a speed in excess of 5° C./second, which may exceed 600° C./second.

A further characteristic of the process is:

    • the coating and the casting are heated to a temperature in excess of 750° C.

The invention also concerns the use of the hot-rolled steel sheet which then can be cold-rolled and coated, for structural and/or anti-intrusion or substructure castings for a land motor vehicle, such as, for example, a bumper bar, a door reinforcement, a wheel spoke.

The description which follows will make the invention clearly understood.

The sheet according to the invention which derives, by reason of its processing, from a hot-rolling mill, possibly may be cold-rerolled again depending on the final thickness desired. It then is coated with an aluminum-based coating, for example by dipping in a bath containing, in addition, from 8% to 11% silicon, from 2% to 4% iron, the sheet having a high mechanical resistance after thermal treatment and a high resistance to corrosion, as well as a good capacity for painting and gluing.

The coating has in particular the function of protecting the basic sheet against hot as well as cold corrosion. The mechanical characteristics in the delivery state of the sheet according to the invention allow a great variety of shaping, in particular a deep stamping. The thermal treatment applied at the time of a hot-shaping process or after shaping makes it possible to obtain high mechanical characteristics which may exceed 1500 MPa for mechanical resistance and 1200 MPa for the limit of elasticity. The final mechanical characteristics are adjustable and depend on the carbon content of the steel and on the thermal treatment.

At the time of thermal treatment performed on a finished casting or at the time of a hot-shaping process, the coating forms a layer having a substantial resistance to abrasion, wear, fatigue, shock, as well as a good resistance to corrosion and a good capacity for painting and gluing.

According to the invention, the steel the weight composition of which is the following:

    • 0.15%<carbon<0.5%
    • 0.5%<manganese<3%
    • 0.1%<silicon<0.5%
    • 0.01%<chromium<1%
    • titanium<0.2%
    • aluminum<0.1%
    • phosphorus<0.1%
    • sulfur<0.05%
    • 0.0005%<boron<0.08%, the remainder being iron and impurities inherent in processing, is processed in the form of a hot-rolled and possibly cold-rolled sheet to obtain the desired thickness. The steel sheet then is coated by dipping, after pickling, in an aluminum bath containing either from 8% to 11% silicon and 2% to 4% iron, or from 2% to 4% iron, or even in an aluminum bath preferably containing from 9% to 10% silicon and 2% to 3.5% iron.

In an example of implementation of a coating of the sheet by dipping in a metal bath containing an aluminum alloy comprising a proportion of approximately 90% aluminum, the coating layer comprises a first alloy layer in contact with the surface of the steel. This layer, directly in contact with the surface of the sheet, is highly alloyed with iron.

A second coating layer, on top of the first, contains approximately 90% aluminum and may contain silicon and a small amount of iron, depending on the composition of the bath.

The first alloy layer may crack when the sheet is shaped for the manufacture of castings.

According to the invention, after the shaping of the casting, the coating is subjected to an increase in temperature at a speed in excess of 5° C./second, which may exceed 600° C./second. This rise in temperature makes possible a rapid remelting of the aluminum which fills in the cracks generated by the operation of shaping of the casting.

Another advantage of the invention lies in the fact that the diffusion of the iron in the coating will be initiated at high temperature. One thus will have a better cohesion between coating and steel in the sheet. In another form of the invention, the thermal treatment may be performed locally, in heavily deformed zones.

In an example of implementation, the steel sheet according to the invention containing 0.21% carbon, 1.14% manganese, 0.020% phosphorus, 0.0038% sulfur, 0.25% silicon, 0.040% aluminum, 0.009% copper, 0.020% nickel, 0.18% chromium, 0.0040% nitrogen, 0.032% titanium, 0.003% boron, 0.0050% calcium is coated with an aluminum-based layer about 20 μm in thickness.

According to the invention the sheet, in the delivery state in a coil or in sheeting, the thickness of which may range between 0.25 mm and 15 mm, has good shaping properties and a good resistance to corrosion as well as a good capacity for painting or gluing.

The sheet, a coated siderurgic product, has a substantial resistance to corrosion in the delivery state, during shaping and thermal treatments as well as during usage of the finished casting. After thermal treatment, a substantial mechanical resistance, which may exceed 1500 MPa, is obtained. The presence of the coating at the time of thermal treatment of the castings makes it possible to prevent any decarbonization of the base metal as well as any oxidation. That is an undeniable advantage, in particular in the case of hot-shaping. Furthermore, heating of the treated casting does not require a furnace having a controlled atmosphere to prevent a decarbonization.

Thermal treatment of the metal in the sheet consists in a heating at a temperature ranging between Ac1, starting temperature of austenitic transformation, for example 750° C. and 1200° C., in a furnace, for a period which depends on the temperature to be reached and the thickness of the casting sheet. The composition is optimized so as to limit the enlargement of the grains at the time of thermal treatment. If the structure sought is completely martensitic, the holding temperature should be in excess of Ac3, for example 840° C., ending temperature of austenitic formation. The temperature holding should be followed by a cooling adjusted to the final structure sought. For a completely martensitic structure and for a steel having the composition of the example, the speed of cooling should be in excess of the critical speed of hardening which is 27° C./s for an austenitizing at 900° C. for 5 min., the sheet having a thickness of approximately 1 mm.

It also is possible to obtain in particular ferrito-bainitic or ferrito-martensitic structures, by a heating at a temperature ranging between Ac1, for example 750° C. and Ac3, for example 840° C., followed by an appropriate cooling. According to the level of resistance to be achieved and the thermal treatment applied, one or several of these phases is/are present in variable proportions. For the highest resistance levels, the structure is composed predominantly of martensite.

Chromium, manganese, boron and carbon are added, in the composition of the steel according to the invention, for their effect on hardenability. In addition, carbon makes it possible to achieve high mechanical characteristics thanks to its effect on the hardness of the martensite.

Aluminum is introduced into the composition in order to trap oxygen and to protect the effectiveness of the boron.

Titanium, the ratio of the content of which with respect to the nitrogen content should be in excess of 3.42, is introduced in order to prevent combining of the boron with the nitrogen, the nitrogen being combined with titanium.

The alloying elements, Mn, Cr, B, make possible a hardenability allowing hardening in the stampers or the use of mild hardening fluids limiting deformation of the castings at the time of thermal treatment. In addition, the composition according to the invention is optimized from the point of view of weldability.

The steel in the sheet may undergo a treatment for globularization of sulfides performed with calcium, which has the effect of improving the fatigue resistance of the sheet.

The steel is particularly suited to the production of structural and anti-intrusion castings.

The proposed coating makes it possible to avoid different surface-preparation operations such as for steel sheets for thermal treatment not having any coating.

The modulation of thermal treatment parameters makes it possible to achieve, with a given composition, different levels of hot and cold sheet resistance according to the thickness sought.

At the time of thermal treatment, the base coating, of aluminum for example, is transformed into a layer alloyed with iron and comprising different phases depending on the thermal treatment and having a considerable hardness which may exceed 600 HV100 g.

Table 2 presents an example of maximal resistance of the steel sheet according to the invention after thermal treatment.

Thermal treatment Rm (MPa)
850° C./5 min. 1695
900° C./5 min. 1675
950° C./5 min. 1665

Claims (25)

What is claimed is:
1. A hot-rolled coated steel sheet comprising a hot-rolled steel sheet coated with an aluminum or aluminum alloy coating, wherein the steel in the sheet comprises the following composition by weight:
0.15%<carbon<0.5%
0.5%<manganese<3%
0.1%<silicon<0.5%
0.01%<chromium<1%
titanium<0.2%
aluminum<0.1%
phosphorus<0.1%
sulfur<0.05%
0.0005%<boron<0.08%, the remainder being iron and impurities inherent in processing, and the steel sheet has a very high mechanical resistance after thermal treatment and the aluminum or aluminum alloy coating provides a high resistance to corrosion of the steel sheet.
2. The coated steel sheet according to claim 1, wherein the composition by weight of the sheet further comprises the following:
0.20%<carbon<0.5%
0.8%<manganese<1.5%
0.1%<silicon<0.35%
0.01%<chromium<1%
titanium<0.1%
aluminum<0.1%
phosphorus<0.05%
sulfur<0.03%
0.0005%<boron<0.01%, the remainder being iron and impurities inherent in processing.
3. A heat treated coated steel sheet prepared by subjecting the coated steel sheet according to claim 2, to an increase in temperature at a speed in excess of 600° C./second.
4. A process for producing a casting comprising
shaping the coated steel sheet of claim 2,
subjecting the shaped coated steel sheet to an increase in temperature at a speed in excess of 5° C./sec.
5. The coated steel sheet according to claim 1, wherein the ratio of titanium to nitrogen in the steel sheet in weight % is in excess of 3.42.
6. A process for producing a casting comprising
shaping the coated steel sheet of claim 5,
subjecting the shaped coated steel sheet to an increase in temperature at a speed in excess of 5° C./sec.
7. The coated steel sheet according to claim 1, wherein the aluminum or aluminum alloy coating comprises from 9% to 10% silicon by weight, from 2% to 3.5% iron by weight, the remainder being aluminum.
8. A process for producing a casting comprising
shaping the coated steel sheet of claim 7,
subjecting the shaped coated steel sheet to an increase in temperature at a speed in excess of 5° C./sec.
9. The coated steel sheet according to claim 1, wherein the coating comprises from 2% to 4% iron by weight, the remainder being aluminum.
10. A process for producing a casting comprising
shaping the coated steel sheet of claim 9,
subjecting the shaped coated steel sheet to an increase in temperature at a speed in excess of 5° C./sec.
11. A process for producing a casting comprising
shaping the coated steel sheet of claim 1,
subjecting the shaped coated steel sheet to an increase in temperature at a speed in excess of 5° C./second.
12. The process according to claim 11, wherein the casting is heated to a temperature in excess of 750° C.
13. A heat treated coated steel sheet prepared by subjecting the coated steel sheet according to claim 1 to an increase in temperature at a speed in excess of 600° C./second.
14. A land motor vehicle comprising the heat treated coated steel of claim 13.
15. A land motor vehicle comprising the coated steel sheet of claim 1.
16. A heat treated coated steel sheet prepared by subjecting the coated steel sheet according to claim 1 to a temperature in excess of 750° C.
17. The heat treated coated steel sheet of claim 16, manufactured by a process comprising hot-shaping the coated steel sheet, and cooling the hot-shaped sheet at a rate that produces martensitic structures, ferrite-martensitic structures, or ferrite-bainitic structures.
18. The coated steel sheet of claim 1 that is manufactured by a process comprising providing said hot rolled steel sheet; and coating said hot rolled steel sheet with an aluminum coating or aluminum alloy coating.
19. The coated steel sheet of claim 18 that is manufactured by dipping said hot rolled steel sheet into a molten aluminum bath or molten aluminum alloy bath.
20. The coated steel sheet of claim 19 that is manufactured by pickling said hot rolled steel sheet before said dipping.
21. The coated steel sheet of claim 20 that is manufactured by cold rolling said hot rolled steel sheet after said pickling.
22. The coated steel sheet of claim 18 that is manufactured by cold rolling said hot rolled steel sheet before said coating.
23. The coated steel sheet of claim 1, wherein said mechanical resistance is in excess of 1000 MPa.
24. The coated steel sheet of claim 1, wherein said mechanical resistance is in excess of 1500 MPa.
25. The coated steel sheet of claim 24 that is composed predominantly of martensite.
US13205126 1998-07-09 2011-08-08 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment Active USRE44153E1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
FR9808793A FR2780984B1 (en) 1998-07-09 1998-07-09 steel hot-rolled sheet and cold COATED and having a high strength after heat treatment
FR9808793 1998-07-09
US09350100 US6296805B1 (en) 1998-07-09 1999-07-09 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment
US13205126 USRE44153E1 (en) 1998-07-09 2011-08-08 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US13205126 USRE44153E1 (en) 1998-07-09 2011-08-08 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment
US13863100 USRE44940E1 (en) 1998-07-09 2013-04-15 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09350100 Reissue US6296805B1 (en) 1998-07-09 1999-07-09 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US09350100 Continuation US6296805B1 (en) 1998-07-09 1999-07-09 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Publications (1)

Publication Number Publication Date
USRE44153E1 true USRE44153E1 (en) 2013-04-16

Family

ID=48049317

Family Applications (2)

Application Number Title Priority Date Filing Date
US13205126 Active USRE44153E1 (en) 1998-07-09 2011-08-08 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment
US13863100 Active USRE44940E1 (en) 1998-07-09 2013-04-15 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Family Applications After (1)

Application Number Title Priority Date Filing Date
US13863100 Active USRE44940E1 (en) 1998-07-09 2013-04-15 Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment

Country Status (1)

Country Link
US (2) USRE44153E1 (en)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1252034B (en)
FR1297906A (en) 1961-05-26 1962-07-06 A method of hot forging of steel products, and new industrial product obtained by this process
US4655852A (en) 1984-11-19 1987-04-07 Rallis Anthony T Method of making aluminized strengthened steel
FR2625227A1 (en) 1987-12-23 1989-06-30 Intraviss Sn Alloy steel for nuts and bolts with checking of tightening using ultrasound
US4891274A (en) * 1986-02-13 1990-01-02 Nippon Steel Corporation Hot-dip aluminum coated steel sheet having excellent corrosion resistance and heat resistance
US5133815A (en) * 1990-03-02 1992-07-28 Kabushiki Kaisha Kobe Seiko Sho Cold-rolled steel sheets or hot-dip galvanized cold-rolled steel sheets for deep drawing
US5178688A (en) 1991-11-30 1993-01-12 Samsung Heavy Industries Co., Ltd. Carburized boron steels for gears
JPH0925551A (en) * 1995-05-10 1997-01-28 Nkk Corp Aluminum-zinc alloy plated steel sheet excellent in press formability and heat resistance
JPH09195021A (en) * 1996-01-18 1997-07-29 Nippon Steel Corp Production of hot-dip aluminum plated steel sheet excellent in heating blackening resistance
US5656102A (en) * 1996-02-27 1997-08-12 Bethlehem Steel Corporation Bake hardenable vanadium containing steel and method thereof

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1252034B (en)
FR1297906A (en) 1961-05-26 1962-07-06 A method of hot forging of steel products, and new industrial product obtained by this process
US4655852A (en) 1984-11-19 1987-04-07 Rallis Anthony T Method of making aluminized strengthened steel
US4891274A (en) * 1986-02-13 1990-01-02 Nippon Steel Corporation Hot-dip aluminum coated steel sheet having excellent corrosion resistance and heat resistance
FR2625227A1 (en) 1987-12-23 1989-06-30 Intraviss Sn Alloy steel for nuts and bolts with checking of tightening using ultrasound
US5133815A (en) * 1990-03-02 1992-07-28 Kabushiki Kaisha Kobe Seiko Sho Cold-rolled steel sheets or hot-dip galvanized cold-rolled steel sheets for deep drawing
US5178688A (en) 1991-11-30 1993-01-12 Samsung Heavy Industries Co., Ltd. Carburized boron steels for gears
JPH0925551A (en) * 1995-05-10 1997-01-28 Nkk Corp Aluminum-zinc alloy plated steel sheet excellent in press formability and heat resistance
JPH09195021A (en) * 1996-01-18 1997-07-29 Nippon Steel Corp Production of hot-dip aluminum plated steel sheet excellent in heating blackening resistance
US5656102A (en) * 1996-02-27 1997-08-12 Bethlehem Steel Corporation Bake hardenable vanadium containing steel and method thereof

Non-Patent Citations (15)

* Cited by examiner, † Cited by third party
Title
"Defendant's Opposition to Plaintiff's Renewed Motion for Judgment as a Matter of Law", In The United States District Court For the District of Delaware, Case No. 1:10-cv-00050SLR, Document #236, Filed Mar. 10, 2011, 28 pages.
"Final Jury Instructions", In The United States District Court For the District of Delaware, Case No. 1:10-cv-00050SLR, Document #212, Filed Jan. 14, 2011, 44 pages.
"Jury Verdict Sheet", In The United States District Court For the District of Delaware, Case No. 1:10-cv-00050SLR, Document #215, Filed Jan. 14, 2011, 7 pages.
"Plaintiff's Opening Brief in Support of Renewed Motion for Judgment as a Matter of Law", In The United States District Court For the District of Delaware, Case No. 1:10-cv-00050SLR, Document #227, Filed Feb. 17, 2011, 29 pages.
"Plaintiff's Reply Brief in Support of Renewed Motion for Judgment as a Matter of Law", In The United States District Court For the District of Delaware, Case No. 1:10-cv-00050SLR, Document #239, Filed Mar. 24, 2011, 17 pages.
Arcelor Mittal v. AK Steel Corp, Decision by the United States Court of Appeals for the Federal Circuit for an appeal from the United States District Court for the District of Delaware in Case No. 10-CV-0050, 2011-1638, Decided Nov. 30, 2012, 25 pages.
Bano et al., "Heat Treated Boron Steels in the Automotive Industry", 39th MWSP Conference Proceedings, ISS, vol. XXXV, 1998, 673-677.
English Translation for Foreign Patent FR 1297906, May 28, 1962, 6 pages.
Ford Engineering Material Specification, "Steel, Sheet, Boron Treated, High Strength", Specification No. WSB-M1A322-A1, 1992, 3 pages.
Gierek, "Tauchalitieren-Eigenschaften und Einsatzgebiete", XP-002114744, 1976, 4 pages.
Gierek, "Tauchalitieren—Eigenschaften und Einsatzgebiete", XP-002114744, 1976, 4 pages.
Patent Abstracts of Japan; vol. 13, No. 457; Oct. 16, 1989; & JP 01 176056; Jul. 12, 1989.
Patent Abstracts of Japan; vol. 15, No. 17; Jan. 14, 1991; & JP 02 263954; Oct. 26, 1990.
Patent Abstracts of Japan; vol. 18, No. 004; Jan. 6, 1994; & JP 05 247588; Sep. 24, 1993.
Patent Abstracts of Japan; vol. 18, No. 523; Oct. 4, 1994; & JP 06 179944; Jun. 28, 1994.

Also Published As

Publication number Publication date Type
USRE44940E1 (en) 2014-06-10 grant

Similar Documents

Publication Publication Date Title
US5470529A (en) High tensile strength steel sheet having improved formability
EP1201780A1 (en) Steel plate having excellent burring workability together with high fatigue strength, and method for producing the same
US20080000555A1 (en) High Strength Thin-Gauge Steel Sheet Excellent in Elongation and Hole Expandability and Method of Production of Same
US20070029015A1 (en) High-yield-ratio high-strength thin steel sheet and high-yield-ratio high-strength hot-dip galvanized thin steel sheet excelling in weldability and ductility as well as high-yield ratio high-strength alloyed hot-dip galvanized thin steel sheet and process for producing the same
JP2007211276A (en) Plated steel sheet for hot-press use, its manufacturing method, and method for manufacturing hot press formed member
JP2007302918A (en) High strength steel sheet with excellent bore expandability and formability, and its manufacturing method
JP2005256020A (en) Low yield ratio type high strength cold rolled steel sheet having excellent shape freezability and manufacturing method therefor
JP2002256386A (en) High strength galvanized steel sheet and production method therefor
JP2003147499A (en) Steel sheet for hot press, and production method therefor
JPH11279691A (en) High strength hot dip galvannealed steel sheet good in workability and its production
JP2005256089A (en) Hot dip galvanized compound high-strength steel sheet having excellent formability and bore expandability and method for manufacturing the same
WO2007075006A1 (en) High manganese steel strips with excellent coatability and superior surface property, coated steel strips using steel strips and method for manufacturing the steel strips
Maikranz‐Valentin et al. Components with Optimised Properties due to Advanced Thermo‐mechanical Process Strategies in Hot Sheet Metal Forming
JP2002115025A (en) Steel sheet having high stretch-flanging property and excellent shape freezability and its production method
JP3663145B2 (en) Method of producing by stamping molded parts with extremely high mechanical characteristic values ​​coated rolled steel sheet, in particular from the strip of covering hot rolled steel sheet
JP2005220430A (en) High strength hot dip galvanized steel sheet having excellent surface quality
EP0971044A1 (en) Clad hot-rolled and cold-rolled steel sheet, presenting a very high resistance after thermal treatment
JPH10130782A (en) Ultrahigh strength cold rolled steel sheet and its production
CN101348883A (en) Niobium and titanium composite added ultra-low carbon baking hardening steel plate and manufacturing method thereof
JP2006176843A (en) High-strength and low-density steel sheet superior in ductility and manufacturing method therefor
WO2007067014A1 (en) Tole d&#39;acier laminee a froid de haute resistance possedant une excellente propriete de formabilite et de revetement, tole d&#39;acier plaquee de metal a base de zinc fabriquee a partir de cette tole et procece de fabrication de celle-ci
CN1782116A (en) 800MPa cold rolled and hot zinc plated double phase steel and its producing method
JPH05255804A (en) Cold rolled steel sheet excellent in formability and rigidity and its manufacture
JP2003129172A (en) Steel sheet superior in workability and shape freezability, and manufacturing method therefor
US4925500A (en) High-strength hot-rolled steel sheet having remarkably excellent cold workability and process for manufacturing the same

Legal Events

Date Code Title Description
AS Assignment

Owner name: ARCELORMITTAL, LUXEMBOURG

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ARCELORMITTAL FRANCE;REEL/FRAME:036044/0282

Effective date: 20141231

AS Assignment

Owner name: SOLLAC, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LAURENT, JEAN-PIERRE;HENNECHART, JEAN-PAUL;SPEHNER, DOMINIQUE;AND OTHERS;REEL/FRAME:036097/0041

Effective date: 19990723

Owner name: USINOR, FRANCE

Free format text: MERGER;ASSIGNOR:SOLLAC;REEL/FRAME:036097/0349

Effective date: 20031221

Owner name: ARCELOR ATLANTIQUE ET LORRAINE, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ARCELOR FRANCE;REEL/FRAME:036097/0596

Effective date: 20060515

Owner name: ARCELOR FRANCE, FRANCE

Free format text: CHANGE OF NAME;ASSIGNOR:USINOR;REEL/FRAME:036097/0545

Effective date: 20060407

Owner name: ARCELOR ATLANTIQUE ET LORRAINE, FRANCE

Free format text: PATENT CO-OWNERSHIP AGREEMENT;ASSIGNOR:ARCELOR FRANCE;REEL/FRAME:036106/0502

Effective date: 20060515

Owner name: ARCELORMITTAL ATLANTIQUE ET LORRAINE, FRANCE

Free format text: CHANGE OF NAME;ASSIGNOR:ARCELOR ATLANTIQUE ET LORRAINE;REEL/FRAME:036107/0330

Effective date: 20071109

Owner name: USINOR, FRANCE

Free format text: CORPORATE DISSOLUTION WITHOUT LIQUIDATION AND TRANSFER OF RIGHTS;ASSIGNOR:SOLLAC;REEL/FRAME:036106/0776

Effective date: 20031020

Owner name: ARCELORMITTAL FRANCE, FRANCE

Free format text: CHANGE OF NAME;ASSIGNOR:ARCELOR FRANCE;REEL/FRAME:036107/0298

Effective date: 20070831

Owner name: ARCELORMITTAL FRANCE, FRANCE

Free format text: CHANGE OF ADDRESS;ASSIGNOR:ARCELORMITTAL FRANCE;REEL/FRAME:036174/0564

Effective date: 20131016

CC Certificate of correction