Production method of ultra fine grain steel
US6464807B1 · kind B1 · utility
1Cited by
2References
2Claims
0Family size
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Key dates
| Filing date | Feb 24, 2000 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Feb 24, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/005
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of producing a ultra fine grain steel made of ferrite having a mean grain size of not larger that 3 &mgr;m as the base phase, after ingoting raw materials, by austenitizing the ingot by heating it to a temperature of at least an Ac 3 point, then, applying compression working of a reduction ratio of at least 50% at a temperature of from an Ae 3 point or lower to an Ar 3 point −150° C., or at a temperature of at least 550° C., and thereafter, cooling, wherein the strain rate as compression working is in the range of from 0.001 to 10/second.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.