EFFECTS OF TEMPERATURE ON FATIGUE CRACK GROWTH RATES OF A LOW-CARBON PIPE STEEL IN THE DUCTILE AND DUCTILE-TO-BRITTLE TRANSITION REGIONS

This study investigated the impact of temperature on fatigue crack growth rates (FCGR) of low-carbon pipe steel in both the ductile and ductile-to-brittle transition regions. Results showed that the FCGRs decreased as the temperature decreased from the ductile to the ductile-to-brittle transition region, while FCGRs remained consistent within the ductile-to-brittle transition region. The Paris law coefficients, C and m, were also influenced by the temperature change between the ductile region and the ductile-to-brittle transition region. However, the C and m values stayed relatively stable in each region. The m values in the ductile-to-brittle transition region were found to be higher than those in the ductile region, whereas the C values were found to be lower.