Method for manufacturing a component of austenitic TWIP or TRIP/TWIP steel

Patent metadata

Field	Value
Publication number	US-11247252-B2
Application number	US-201615743366-A
Country	US
Kind code	B2
Filing date	Jul 8, 2016
Priority date	Jul 16, 2015
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

The present invention relates to a method for manufacturing a component of austenitic TWIP or TRIP/TWIP steel. A flat product ( 1 ) is deformed by achieving at least one indentation ( 16 ) on at least one surface of the flat product ( 1 ) in order to have in the deformed product ( 5 ) areas of a high strength steel embedded in a matrix of a ductile material. The invention also relates to the use of the component where areas of a high strength steel embedded in a matrix of a ductile material are required in the same component.

First claim

The invention claimed is:

1. A high strength sheet comprising austenitic twinning induced plasticity (TWIP) or transformation induced plasticity/twinning induced plasticity (TRIP/TWIP) steel with deformed indentations having areas of high strength in a matrix of ductile material, wherein a hardness of the sheet in an area of the indentations is reversible by annealing the sheet at a temperature of 900-1250° C.

2. The high strength sheet of claim 1 , wherein the annealing temperature is 900-1050° C.

3. The high strength sheet of claim 1 , wherein the sheet comprises 10-25 weight % manganese and has interstitial disengaged nitrogen and carbon atoms, wherein a total carbon and nitrogen content is 0.4-0.8 weight %.

4. The high strength sheet of claim 3 , wherein the sheet further comprises 10-20.5 weight % chromium and 3.5-9.5 weight % nickel.

5. The high strength sheet of claim 1 , wherein the sheet has a stacking fault energy of 20-30 mJ/m 2 .

6. The high strength sheet according to claim 1 , wherein a thickness of the sheet in an area outside of the indentations is 0.15-4.0 millimeter.

7. The high strength sheet according to claim 6 , wherein a depth of the indentations is up to 30% of a thickness of the sheet in an area outside of the indentations.

8. The high strength sheet according to claim 7 , wherein the TWIP or TRIP/TWIP effect is directly proportional to the indentation depth.

9. The high strength sheet according to claim 6 , wherein the indentations have a shape of a honeycomb, a wave, a triangle, a rectangle, a circle, a cross, a line, a ripple, a cobweb, or any combination of these geometries.

10. A method for manufacturing the high strength sheet of claim 1 , wherein an austenitic twinning induced plasticity (TWIP) or transformation induced plasticity/twinning induced plasticity (TRIP/TWIP) steel sheet is deformed by achieving at least one indentation on at least one surface of the steel sheet in order to have, in the deformed product, areas of a high strength embedded in a matrix of a ductile material.

11. The method according to claim 10 , wherein deformation of the steel sheet is achieved by cold rolling using at least one roll that is a profiled roll in order to create at least one indentation in a direction transverse to the rolling direction with a desired geometry on the surface of the steel sheet.

12. The method according to claim 10 , wherein deformation of the steel sheet is achieved by cold rolling using at least one roll that is a profiled roll in order to create two or more indentations in a direction parallel to the rolling direction with a desired geometry on the surface of the steel sheet.

13. The method according to claim 10 , wherein deformation of the steel sheet is achieved by cold rolling using at least one roll that is a profiled roll in order to create two or more indentations both in a direction transverse to the rolling direction and in a direction parallel to the rolling direction with a desired geometry on the surface of the steel sheet.

Assignees

• Outokumpu Oy

Inventors

• Fröhlich Thomas
• Lindner Stefan

Classifications

• B21C37/02

  of sheets · CPC title

• C22C38/04

  containing manganese · CPC title

• C21D1/02

  Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation · CPC title

• C21D7/04

  of the surface · CPC title

• B21B2001/221

  by cold-rolling · CPC title