Affiliation:
1. Division of Materials Technology, Department of Materials Science and Engineering, Royal Institute of Technology, S-100 44 Stockholm, Sweden
Abstract
Carbide coarsening has been investigated in a 12 percent CrMoV steel. Studies in the gauge length (creep exposed) and in the head (stress free ageing) for both interrupted and ruptured creep specimens tested at an initial stress of 80 MPa at various temperatures and at 600°C at different initial stresses have been performed. The measured quantities include hardness, carbide sizes in the tempered martensite, at the former austenite grain boundaries and at the δ-ferrite boundaries as well as mean free distance between carbides, total number of carbides, and carbide size distribution. The contributions to the increase of strain rate in the tertiary creep are discussed in terms of plastic deformation, cavitation accumulation, and microstructural degradation. By using a strain and strain rate relation, expressions to quantitatively account for each contribution to increase of strain rate are given. The increase of strain rate, thereby rupture, is mainly caused by the microstructural degradation due to carbide coarsening and by the cavitation accumulation.
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science
Reference21 articles.
1. ECSC Information Day: The Manufacture and Properties of Steel 91 for the Power Plant and Process Industries: VDEh, Du¨sseldorf, November, 1992.
2. Sandstro¨m R. , KarlssonS., and ModinS., “The Residual Lifetime of Creep-Deformed Material, Microstructure Changes Occurring during Creep of a 12% CrMoWV Steel,” High Temperature Technology, Vol. 3, No. 2, May, 1985, pp. 71–78.
3. Gooch D. J. , “Creep Fracture of 12Cr-Mo-V Steel,” Metal Science, Vol. 16, Feb., 1982, pp. 79–89.
4. Eggeler G. , “The Effect of Long-Term Creep on Particle Coarsening in Tempered Martensite Ferritic Steels,” Acta Metal., Vol. 37, No. 12, 1989, pp. 3225–3234.
5. Wu R. , and Sandstro¨mR., “Creep Cavity Nucleation and Growth in 12% CrMoV Steel,” Materials Science and Technology, Vol. 11, No. 6, June 1995, pp. 579–588.
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献