Investigation of carbide precipitates as hydrogen traps and their role in hydrogen embrittlement susceptibility of twinning-induced plasticity steel

Solution and aging twinning-induced plasticity (TWIP) steel were obtained by the solution-treated at 1150°C for 2 h and aging-treated at 700°C for 6 and 24 h. Carbide precipitation is generated in the grain boundary and formed inside grains for aging time prolonging. Scanning Kelvin probe force microscopy was used to investigate the local distribution of hydrogen after hydrogen charging in TWIP steel with carbides in grain boundaries and grains. Results showed that carbides at the grain boundary adsorbed more hydrogen than those in the grain. Carbide precipitated phase as a hydrogen trap can enhance the resistance to hydrogen embrittlement and generated more secondary cracks at the grain boundary.