Hydrogen diffusion and hydrogen embrittlement of a 1500 MPa hot-stamped steel 22MnB5 in different austenitizing conditions
Huixing Li, Chang-wook Lee, Jeffrey Venezuela, Hye-Jin Kim, Andrej Atrens
Abstract
We investigated the influence of hydrogen on a 1500 MPa hot-stamped steel 22MnB5 with different prior austenite grain size (PAGS, ranging from 14.0 μm to 22.2 μm), which were produced by precise control of the austenitizing temperature and time. All steel specimen exhibited a significant reduction of ductility (e.g., by 70%) and a small decrease in ultimate tensile strength (≤15%), measured using the linearly increasing stress test. The effect of PAGS on hydrogen embrittlement of the hot-stamped steel was not significant for these test conditions. Martensite with smaller PAGS exhibited a slightly lower hydrogen diffusion coefficient. Fracture for all steel variants after yielding occurred for hydrogen contents greater than those that actually occur during service.