Enhancing the hydrogen embrittlement resistance with cementite/VC multiple precipitates in high-strength steel

The superior hydrogen embrittlement (HE) resistance and satisfied work hardening capacity are achieved in high-strength spring steel after hydrogen pre-charging with dispersed multiple precipitates via the multi-microalloying of 1.04 wt% Cr and 0.14 wt% V. The precipitates are determined to be the triplex microstructures, i.e., the isolated (Mn, Cr, V)-enriched cementite, isolated V-enriched VC, and the co-precipitation of cementite and VC. These multiple precipitates could act as the effective hydrogen traps to achieve more potent irreversible hydrogen trapping capacity, thus inhibiting the HE susceptibility by ∼23%. Hence, the strategy of cementite/VC multiple precipitates is beneficial in designing the high-strength and HE-resistant automotive steels.