氢在双相不锈钢中的扩散模拟

Duplex stainless steels (DSS) are subjected to a deleterious effect known as hydrogen embrittlement. Due to the difference of the ratio of various alloying elements and the influence of processing technology, the volume fraction of austenite phase (φ_γ) will be changed. Hydrogen diffusion models with different φ_γ were established based on transient finite element mass diffusion in program-Abaqus. In addition, the discrepancies of hydrogen diffusion in both transverse and longitudinal microstructure were implemented. After the simulation analysis, the apparent diffusion coefficients (D_app) of the models were calculated. The results show that D_app decreased with the increase of φ_γ, and there is a linear relationship between ln D_app and φ_γ; the values of hydrogen diffusion coefficient are greater when the elongated austenite is orientated parallel with the direction of hydrogen flux, i.e. the transverse samples are more susceptible to hydrogen embrittlement than longitudinal samples.