Martensitic heat-resisting steel excellent in HAZ-softening resistance and process for producing the same
US5650024A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 25, 1995 |
| Grant date | Jul 22, 1997 |
| Priority date | — |
| Expiry date | Aug 25, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A martensitic heat-resisting steel comprises, in terms of % by mass, 0.01 to 0.30% of C, 0.02 of 0.80% of Si, 0.20 to 1.00% of Mn, 5.00 to 18.00% of Cr, 0.005 to 1.00% of Mo, 0.20 to 3.50% of W, 0.02 to 1.00% of V, 0.01 to 0.50% of Nb, 0.01 to 0.25% of N, and at least one element selected from the group consisting of Ti, Zr, Ta and Hf in an amount of 0.005 to 2.0% for each of the elements, the volume of (Ti %+Zr %+Ta %+Hf %) in the metal component M of M.sub.23 C.sub.6 type carbides therein being from 5 to 65%. The heat-resisting steel is produced by a process comprising the steps of adding Ti, Zr, Ta and Hf to a molten steel having chemical components as mentioned above, during the period from 10 minutes before completion of refining to completion of refining, casting said molten steel, working the resulting casting, solution treating said worked product, subjecting said worked product to temporary cooling stop at a temperature from 950.degree. to 1,000.degree. C. in the course of cooling said hot worked product, and holding said worked product at the temperature for 5 to 60 minutes. The heat-resisting steel is excellent in HAZ-softening resistance, and exhibits a high creep stren…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.