Hydrogen Embrittlement of Advanced High-Strength Steel for Automobile Application: A Review

The hydrogen embrittlement (HE) fracture of advanced high-strength steels used in lightweight automobiles has received increasing public attention. The source, transmission, and movement of hydrogen, characterization parameters, and test methods of HE, as well as the characteristics and path of HE fractures, are introduced. The mechanisms and modes of crack propagation of HE and hydrogen-induced delayed fracture are reviewed. The recent progress surrounding micro and macro typical fracture characteristics and the influencing factors of HE are discussed. Finally, methods for improving HE resistance can be summarized as follows: (1) reducing crystalline grain and inclusion sizes (oxides, sulfides, and titanium nitride), (2) controlling nano-precipitates (niobium carbide, titanium carbide, and composite precipitation), and (3) increasing residual austenite content under the reasonable tension strength of steel.