TEMPERATURE-DEPENDENCE OF LOW-CYCLE FATIGUE BEHAVIOR OF MARTENSITIC STAINLESS-STEELS

Low cycle fatigue tests were carried out on two kinds of martensitic stainless steels (types 403 and 616) at room temperature, 400, 500 and 600 °C. For both materials cyclic softening behaviour was observed at each test temperature. The temperature and material dependences of low cycle fatigue life for a given plastic strain range coincide qualitatively with the dependences of reduction in area in a tensile test; however, the dependences cannot be explained quantitatively by the equations of Coffin or Manson. Fatigue lives estimated by Tomkins' analysis coincide with experimental values when Δε{lunate}p (Δσ/σu)2 is used as a mechanical parameter. © 1979.