Heat-treating tubular steel sections
US4204892A · kind A · utility
17Cited by
1References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 13, 1978 |
| Grant date | May 27, 1980 |
| Priority date | — |
| Expiry date | Oct 13, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/909
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A tubular steel section at a temperature, above Ac.sub.1, at which the steel contains at most 15% ferrite is subjected to martensitic and/or bainitic quenching followed by still air cooling. The effects of quenching are limited to a surface layer, internal and/or external, of the section. At the end of the quenching step the part of the section remote from the quenched surface layer or layers is at a temperature above 675.degree. C. which permits self-tempering of the quenched surface layer or layers at a temperature above 450.degree. C. and ensures transformation of residual austenite to a martensite-free structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.