Cold-rolled steel sheet with controlled microstructure, grain diameters, and texture
US9580767B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2013 |
| Grant date | Feb 28, 2017 |
| Priority date | — |
| Expiry date | Nov 3, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12972
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength cold-rolled steel sheet includes a composition having controlled amounts of carbon, silicon, manganese, phosphorous, sulfur, titanium, niobium, sol. Aluminum, chromium, molybdenum, vanadium, boron, calcium, REM, and iron. A microstructure thereof has a main phase of ferrite of at least 40 area %, and a second phase of a low-temperature transformation phase consisting either or both of martensite and bainite, which comprises at least 10 area % in total and retained austenite (γ) at least comprising 3 area % . An average grain diameter of ferrite has a tilt angle of at least 15° is at most 5.0 mm, an average grain diameter of the low-temperature transformation-produced phase is at most 2.0 mm, an average grain diameter of lump-like retained γ having an aspect ratio of less than 5 is at most 1.5 mm, and an area fraction of the lump-like retained γ relative to the retained γ is at least 50%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.