High-nitrogen ferritic heat-resisting steel with high niobium content and method of production thereof
US5254307A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 28, 1992 |
| Grant date | Oct 19, 1993 |
| Priority date | — |
| Expiry date | Apr 28, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-nitrogen ferritic heat-resisting steel with high niobium content comprises, in weight per cent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.005-1.00% Mo, 0.20-1.50% W, 0.05-1.00% V, over 0.12 up to 2.00% Nb and 0.10-0.50%N, the balance being Fe and unavoidable impurities. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the resulting melt in an atmosphere controlled to have a total pressure of not less than 2.5 bar and a nitrogen partial pressure of not less than 1.0 bar, with the relationship between the nitrogen partial pressure p and the total pressure P being EQU P>2.5p.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.