Fatigue crack growth rates of rotor steel at elevated temperatures

Abstract

Low fatigue samples were obtained from the outer edges of rotor steel (30CrlMolV) which had operated under different temperatures conditions. Based on this data, the effects of temperature on fatigue crack growth rates were investigated. This paper presents a derivation of the superposition expression of two natural logarithms governing crack growth rates and also discusses the relationship between a material’s constants and temperature. These results can provide experimental and theoretical references for fatigue life design of rotor steel in steam turbines.

Keywords

rotor steels (30CrlMolV) / fatigue crack propagation rate / temperature

References

[1] Rice J. R. Fracture mechanics[J]. Appl Mech Rev, 1985, 38(10): 1271-1275

[2] Paris P. C. Fracture mechanics and fatigue: a historical perspective[J]. Fat Frac of Eng Mat and Structures, 1998, 21: 535-540

[3] Paris P. C., Erdugam F. Critical analysis of crack propagation laws[J]. Trans ASME J Basic Eng, 1963, 85: 528-534

[4] Webster G. A. Methods of estimating C*[J]. Materials at High Temperatures, 1992, 10(2): 74-78

[5] Surech S. Fatigue Materials[M]. 1991, Cambridge: Cambridge University Press, 1-147

[6] Liaw P. K., Swarminathan V. P. Elevated-temperature fatigue crack growth behavior of a rotor steel[J]. Eng Frac Mech, 1989, 34(2): 457-463

[7] E647-86a, 1987 Annual Book of ASTM Standards[S].

[8] JEGLIC F. ASME STP520[M]. Philadelphia, Pa, 1973: 139–148.