High-strength steel plate having high dynamic deformation resistance and method of manufacturing the same
US6319338A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Jul 6, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The object of the present invention is to provide high-strength steel sheets exhibiting high impact energy absorption properties, as steel materials, to be used for shaping and working into such parts as front side members of automobiles which absorb impact energy upon collision, as well as a method for their production. The high-strength steel sheets of the invention which exhibit high impact energy absorption properties are high-strength steel sheets with high flow stress during dynamic deformation characterized in that the microstructure of the steel sheets in their final form is a composite microstructure of a mixture of ferrite and/or bainite, either of which is the dominant phase, and a third phase including retained austenite at a volume fraction between 3% and 50%, wherein the average value .sigma.dyn (MPa) of the flow stress in the range of 3.about.10% of equivalent strain when deformed in a strain rate range of 5.times.10.sup.2.about.5.times.10.sup.3 (1/sec) after pre-deformation of greater than 0% and less than or equal to 10% of equivalent strain, satisfies the inequality: .sigma.dyn.gtoreq.0.766.times.TS+250 as expressed in terms of the maximum stress TS (MPa) in the s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.