Medium carbon steel sheet for cold working and method for manufacturing the same
US9840750B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2011 |
| Grant date | Dec 12, 2017 |
| Priority date | — |
| Expiry date | Jul 24, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A medium carbon steel sheet for cold working that has a hardness of 500 HV to 900 HV when subjected to high-frequency quenching and a quick cooling to a room temperature is carried out. The medium carbon steel sheet includes, by mass %, C: 0.30 to 0.60%, Si: 0.06 to 0.30%, Mn: 0.3 to 2.0%, P: 0.03% or less, S: 0.0075% or less, Al: 0.005 to 0.10%, N: 0.001 to 0.01%, and Cr: 0.001 to 0.10%, the balance composed of Fe and inevitable impurities. An average diameter d of a carbide is 0.6 μm or less, a spheroidizing ratio p of the carbide is equal to or more than 70% and less than 90%, and the average diameter d (μm) of the carbide and the spheroidizing ratio p % of the carbide satisfy the expression d≦0.04×p−2.6.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.