Investigation of Thermal Aging Effect on Fracture Toughness of Cast Stainless Steels Using Experimental and Numerical Approach

This paper investigates effect of thermal aging on reduction of fracture toughness of CF8 M cast stainless steel. To predict fracture toughness of un-aged and aged materials by numerical analyses, finite element damage analysis is used in conjunction with strain-based fracture model. The strain-based fracture models for un-aged and aged CF8 M are determined from notched bar tensile test data and finite element analysis of it. It is found that the effect of thermal aging on material ductility can be quantified with introducing the concept of thermal aging constant. Using the method in this paper, J-resistance curves for un-aged and aged CF8 M can be predicted and compared with experimental test data.