Prediction of the damage and fracture of cast steel containing pores

For spatial design freedom, steel castings are widely used in bridges, airport terminals, and offshore platforms. However, different from hot-rolling technology, casting process variables, such as the casting temperature and those related to graphite spheroidization and post-heat treatment, may cause casting defects. To improve the safety and effectiveness of steel castings, a study consisting of experiments and numerical calculations is performed to investigate the effect of pores on the damage and fracture of cast steel. The chemical composition, metallography, and tomographic imaging of cast and hot-rolled steels were compared, providing a clear understanding of cast steel at the microstructure level. In addition, a complete Gurson–Tvergaard–Needleman damage model is used to predict the ductile fracture of cast steel containing pores. Good agreement is obtained between the measured and predicted tensile curves as well as between the measured and predicted void volume fraction evolution.