High-Temperature Intergranular Crack Growth in Martensitic 2-1/4 Cr1Mo Steel,
Abstract
Micromechanisms of high-temperature crack growth in martensitic 2 1/4cr-lMo steel have been studied in vacuum, under static loading at 500 C. Detailed metallographic and fractographic measurements have been combined with Scanning Auger Microscopy and crack growth resistance curves to characterize the micro-mechanisms of failure. At low stress intensities, the mode of crack growth is high-temperature brittle intergranular fracture (HTBIGF) and is controlled by the dynamic segregation of sulphur to crack-tip regions. Crack advance appears to occur by discrete jumps when a critical concentration of sulphur is achieved over the jump-distance. At high stress intensities, the mode of fracture changes to intergranular microvoid coalescence (IGMVC), and is controlled by the distribution of sulphides. Of crucial importance are the relatively fine sulphides that reprecipitate from solid solution during the austenitising treatment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1987
- Accession Number
- ADA191817
Entities
People
- C. A. Hippsley
- P. Bowen