Process for producing steel bar wire rod for cold working
US5252153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1992 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Jun 10, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/003
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel comprising 0.1 to 1.5% of C and 0.25 to 2.0% of Mn is heated to 900.degree. to 1250.degree. C., and the heated steel is hot-rolled at a temperature in the range of from Ar.sub.3 to (Ar.sub.3 +200).degree. C. or Arcm to (Arcm+200).degree. C. with a total reduction of area of 30% or more. The hot-rolled material is cooled to complete a ferrite/pearlite transformation or a pro-eutectoid cementite/pearlite transformation. The transformed material is subjected to finish hot rolling at a temperature in the range of from (Ac.sub.1 -400) to Ac.sub.1 .degree. C. with a total reduction ratio of 10 to 70%. If necessary, the material after the finish hot rolling is cooled to 300.degree. C. at an average cooling rate of 1.degree. C./sec or less. A spheroidization annealing of the steel bar wire rod produced according to the process of the present invention enables a good spheroidized texture to be formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.