Strength Change in Ultra Low Carbon Steel due to Carburizing Heat Treatment for Hot Press Forming

摘要

Strength change in ultra low carbon steel carburized at 880 °C and 930 °C for 10, 30, 60 and 120 minutes was investigated. The results were analyzed by a tensile test, chemical composition analysis, optical microscopy and scanning electron microscopy. Stress in the 0.5% strain specimen in the tensile test increased as the time treated at 880 °C and 930 °C increased, because the carbon diffusion layer and the martensite of the specimen increased with increasing treatment time. Martensite was found in the ferrite region in the specimen treated at 880°C, which is attributed to grain boundary diffusion;