公开(公告)号：US20210032714A1

公开(公告)日：2021-02-04

申请号：US16968255

申请日：2019-02-08

Applicant: TATA STEEL IJMUIDEN B.V.

Inventor： Radhakanta RANA

IPC: C21D6/00 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  B32B15/01 ,  C21D1/673 ,  C21D1/18

Abstract: A method of shaping an article from a zinc or zinc alloy coated steel blank, including the steps of: a) providing a blank of the zinc or zinc alloy coated steel; b) reheating of the blank obtained in step a) to a reheating temperature TRH in the range Ac3-200° C. of the steel; c) soaking the blank for a time up to 3 minutes at the reheating temperature TRH; d) shaping the article in a press; and e) cooling the article. The steel includes (in wt. %) C: 0.01-0.2; Mn: 3.1-9.0; Al: 0.5-3.0; and optionally further alloying elements selected from Si, Cr, V, Nb, Ti and Mo; inevitable impurities and the balance is Fe.

公开(公告)号：US20230010877A1

公开(公告)日：2023-01-12

申请号：US17780451

申请日：2020-11-27

Applicant: TATA STEEL IJMUIDEN B.V.

Inventor： Radhakanta RANA

IPC: C21D8/02 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C23C2/06 ,  C23C2/40 ,  C21D9/52

Abstract: A method of manufacturing steel strip including the steps of: casting molten steel into slabs;
reheating the slabs at 1150° C. or more for 1 hour or more;
hot rolling the steel into a strip, preferably with an average F1 slab entry temperature above 1000° C.;
coiling the hot rolled steel strip;
batch annealing the steel strip:
at an intercritical temperature (i.e. between Ac1 and Ac3), preferably below 700° C.;
in non-oxidising and non-nitrogenated atmosphere;
total annealing time at least 5 hours, preferably at least 10 hours to get Mn enrichment in austenite such that Mn content is at least 1.25 times bulk Mn content of the steel and C enrichment such that C content is at least 1.2 times bulk C content of the steel; cooling the steel after batch annealing in air, forced air or water quench.

公开(公告)号：US20230002870A1

公开(公告)日：2023-01-05

申请号：US17780477

申请日：2020-11-27

Applicant: TATA STEEL IJMUIDEN B.V.

Inventor： Radhakanta RANA ,  Petrus Cornelis Jozef BEENTJES

IPC: C22C38/06 ,  C22C38/04 ,  C21D8/02 ,  C21D9/46 ,  C23C2/06 ,  C23G1/08 ,  C23C2/40

Abstract: Method of hot press forming an article from zinc or zinc alloy coated steel, wherein the steel is a product obtained by: casting the molten steel into slabs; reheating the slabs; hot rolling the steel into a strip, preferably with an FRT above Ar3; coiling the hot rolled steel strip; pickling the hot rolled steel strip; continuous annealing the strip; hot dip coating the steel strip with the zinc or zinc alloy whilst: using a dipping time of 3 seconds or more; maintaining in the hot dip bath a bath temperature of 420° C. to 500° C.; wherein the zinc bath contains essentially zinc, at least 0.1% Al, and optionally up to 5% Al and optionally up to 4% Mg, the rest of the bath including further elements all individually less than 0.3%, and unavoidable impurities; hot press forming the article.

公开(公告)号：US20230081354A1

公开(公告)日：2023-03-16

申请号：US17760448

申请日：2021-02-11

Applicant: TATA STEEL IJMUIDEN B.V.

Inventor： Radhakanta RANA

IPC: C21D9/52 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B32B15/01 ,  C21D8/02 ,  C21D6/00

Abstract: A hot-rolled (HR) strip steel with high flangeability at ultra-high strength levels with a high total elongation, bendability and toughness values, and a method of manufacturing the hot-rolled steel and use thereof.

公开(公告)号：US20210156012A1

公开(公告)日：2021-05-27

申请号：US16633198

申请日：2018-07-23

Applicant: TATA STEEL IJMUIDEN B.V.

Inventor： Radhakanta RANA

IPC: C22C38/38 ,  B21D22/02 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C23C2/06 ,  C23C2/40

Abstract: A steel strip, sheet or blank for producing hot formed parts containing at least the following composition in weight %: C: 0.03-0.17, Mn: 0.65-2.50, Cr: 0.2-2.0, Ti: 0.01-0.10, Nb: 0.01-0.10, B: 0.0005-0.005, N: ≤0.01, wherein Ti/N≥3.42. A hot formed part produced from such a steel strip, sheet or blank, to the use of such a hot formed part, and to a method for forming such a steel blank or a preformed part made from such a blank, into a part.

公开(公告)号：US20210115527A1

公开(公告)日：2021-04-22

申请号：US16463420

申请日：2017-11-24

Applicant: TATA STEEL IJMUIDEN B.V.

Inventor： Shangping CHEN ,  Christiaan Theodorus LAHAYE ,  Radhakanta RANA ,  Guido Cornelis HENSEN

IPC: C21D1/19 ,  C21D9/00 ,  C23C2/06 ,  C22C38/38 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/06 ,  C22C38/22

Abstract: A method for hot-forming a steel blank into an article including the steps of: a. heating a steel blank to a temperature T1 and holding the heated blank at T1 during a time period t1, wherein T1 is in the range of Ac1 to Ac3+200° C. and wherein t1 is at most 12 minutes, b. transferring the heated blank to a hot-forming tool during a transport time t2 during which the temperature of the heated blank decreases from temperature T1 to a temperature T2, wherein T2 is above Ar1 and wherein the transport time t2 is at most 12 seconds, c. forming the blank in the hot-forming tool into an article and quenching it in the hot-forming tool from a temperature T2 to a temperature T3 at a cooling velocity V2 of 25° C./s or more, d. isothermal holding the article at a temperature T4 for a time period t4, e. wherein temperature T3 and/or temperature T4 is between Ms and Mf and wherein t4 is more than 10 seconds and less than 10 minutes, f. cooling the article from temperature T4 to room temperature at a cooling velocity V4. The invention also relates to a hot-formed article obtained by the method.