ABSTRACT The present study is aimed at experiments/analyses on monotonic and cyclic fracture behavior of C‐Mn steel at temperatures ( T ) varying from 28°C to 300°C. The fracture tests have been performed on standard compact tension specimens under different crack mouth opening displacement (CMOD) rates and load ratios ( R : 0, −0.5, and −1) in a dynamic strain aging (DSA) regime. The fracture toughness in terms of () curves are compared for different test variables ( T , R , and CMOD rate). The least fracture resistance curve has been observed at 300°C for fast CMOD rate under R = −1. The fracture resistance curves are also plotted using the proposed to account for additional damage under cyclic fracture. The proposed considers conventional J and Δ J to account for damage owing to tearing and fatigue, respectively. The fracture toughness in terms of and are compared for test conditions. Proposed curves are approximately independent load ratios of 0 and −0.5 for a given temperature and CMOD rate. Further, fractographic investigations have been performed to bring out the individual effect of temperature, load ratio, and loading rate on fracture toughness curves.
Bharadwaj et al. (Tue,) studied this question.