Hydrogen Trapping in Some Automotive Martensitic Advanced High‐Strength Steels

Hydrogen permeation experiments are used to investigate hydrogen trapping in commercial automotive martensitic advanced high‐strength steels. Hydrogen trapping increases with increasing mechanical strength, as indicated by (i) the decrease in the hydrogen diffusion coefficient, and (ii) the increase in reversible hydrogen trap density. The measured trap densities are in the order of ≈1017– ≈ 1018 cm−3. The relationship between trapping characteristics and HE susceptibility of MS‐AHSS is discussed in terms of Hydrogen Enhanced Macroscopic Plasticity (HEMP) and Hydrogen Assisted Micro‐fracture (HAM).