High strength and high toughness stainless steel sheet and method for producing thereof
US5314549A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1993 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Jul 29, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0205
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A stainless steel sheet essentially consisting of: 0.01 to 0.2 wt. % C, 0.1 to 2 wt. % Si, 0.1 to 2 wt. % Mn, 4 to 11 wt. % Ni, 13 to 20 wt. % Cr, 0.01 to 0.2 wt. % N, 0.0005 to 0.0025 wt. % sol.Al, 0.002 to 0.01 wt. % O, 0.009 wt. % or less S, and the balance being Fe and inevitable impurities; the sheet containing 40 to 90% martensite; and the steel sheet having a 1400 N/mm.sup.2 or more tensile stress when a tensile strain is 1.0%. The invention also provides a method for producing a stainless steel sheet comprising the steps of: applying to the steel sheet a process of first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.3)--the final annealing--fourth cold rolling (CR.sub.4)--low temperature heat treatment; the first-, second- and third cold reduction ratio being 30% to 60%; the annealing temperatures in the first-, second- and final annealing being in the range of 950.degree. C. to 1100.degree. C.; the fourth cold reduction ratio being 66% to 76%; and the low temperature heat treatment ranging 300.degree. C. to 600.degree. C. for a period of 0.1 sec to 300 sec.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.