Method for improving creep resistance and low cycle fatigue properties of pressure-containing components
US7833362B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2008 |
| Grant date | Nov 16, 2010 |
| Priority date | — |
| Expiry date | Feb 20, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method by which high temperature properties of a ductile iron alloy, including creep and LCF properties, can be increased for pressure-containing components that are subject to creep and low cycle fatigue. The method comprises modifying the ductile iron alloy to contain 0.4 to 0.8 weight percent molybdenum. A casting of the modified ductile iron alloy is produced and then annealed at a temperature of at least 725° C. for not less than five hours to eliminate carbides and/or stabilize pearlite in the casting. The annealed casting of the modified ductile iron alloy exhibits improved creep resistance and low cycle fatigue properties in comparison to an identical casting of a ductile iron alloy that does not contain molybdenum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.