Study of Diffusible Behavior of Hydrogen in First Generation Advanced High Strength Steels

This study deals with microstructural influence on the H permeation behavior of Dual-Phase (DP) and Complex Phase (CP) steels using electrochemical permeation studies. The H diffusion coefficients in DP steels (DP800: 1.65 x 10(-10) m(2)center dot s(-1), DP1000: 1.58 x 10(-10) m(2)center dot s(-1)) are half of that found in CP steels (3.07 x 10(-10) m(2)center dot s(-1)).The banded microstructure along the specimen thickness and higher C content of the DP led to high H diffusivity of DP steels. The lower total H concentration along with a higher fraction of H was present in the stronger traps in CP steels suggest a better HE resistance of this steel. The H distribution in the specimens was non-uniform, with a higher H concentration speculated near the charging surface.

Automated summary

The banded microstructure and higher C content in DP steels resulted in higher H diffusivity, while the higher fraction of H present in stronger traps in CP steels suggests better hydrogen embrittlement resistance. The non-uniform distribution of H in the specimens with higher concentration near the charging surface was also observed.