Low cycle fatigue behavior of Sanicro25 steel at room and at elevated temperature

作者：Polak Jaroslav^*; Petras Roman; Heczko Milan; Kubena Ivo; Kruml Tomas; Chai Guocai

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2014, 615: 175-182.

DOI：10.1016/j.msea.2014.07.075

• Sanicro 25 steel
• Cyclic plasticity
• Dislocation structure
• Fatigue life
• Effect of temperature

Austenitic heat resistant Sanicro 25 steel developed for high temperature applications in power generation industry has been subjected to strain controlled low cycle fatigue tests at ambient and at elevated temperature in a wide interval of strain amplitudes. Fatigue hardening/softening curves, cyclic stress strain curves and fatigue life curves were evaluated at room temperature and at 700 degrees C. The internal dislocation structures of the material at room and at elevated temperature were studied using transmission electron microscopy. High resolution surface observations and FIB cuts revealed early damage at room temperature in the form of persistent slip bands and at elevated temperature as oxidized grain boundary cracks. Dislocation arrangement study and surface observations were used to identify the cyclic slip localization and to discuss the fatigue softening/hardening behavior and the temperature dependence of the fatigue life.

• 出版日期2014-10-6