High toughness steel and a method for manufacturing the same
US6348108B1 · kind B1 · utility
8Cited by
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2Claims
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Key dates
| Filing date | Mar 2, 1999 |
| Grant date | Feb 19, 2002 |
| Priority date | — |
| Expiry date | Mar 2, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2201/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Ups and downs having a cycle of not more than 5 &mgr;m and an amplitude of not less than 200 nm are formed in a part of not less than 70% per unit length of a prior-austenite grain boundary which is observed in a linear form when seen from a vertical plane by a series of steps of subjecting a steel in a state of austenite to a deformation in not less than 30% of a total area reduction rate at a temperature region which is lower than recrystallization temperature of austenite, and subsequently cooling a deformed steel without causing neither recrystallization nor phase transformation of a diffusion type.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.