电化学充氢对Cr15铁素体不锈钢和304奥氏体不锈钢氢脆敏感性的影响

Effect of Electrochemical Hydrogen Charging on Hydrogen Embrittlement Sensitivity of Cr15 Ferritic and 304 Austenitic Stainless Steels

研究了充氢时间、充氢电流密度、晶体结构对不锈钢氢脆敏感性的影响。结果表明:对于铁素体不锈钢,随着充氢时间的延长、电流密度的增大,塑性显著降低,氢脆敏感性大幅度增加;通过SEM观察实验钢断口形貌,断裂类型由韧性断裂转变为脆性断裂。而相同条件下,奥氏体不锈钢氢脆敏感性较低,抗氢脆性能较好。充氢后实验钢表面存在大量H,且氢含量随试样深度逐渐降低,晶界可能作为氢陷阱影响实验钢的氢脆敏感性。

The effect of the charging time and current density of the electrochemical hydrogen charging process, as well as the crystallographic structure of the steel on the hydrogen embrittlement sensitivity of stainless steels were assessed via slow strain rate tensile test. The results showed that for ferritic stainless steel, with the increase of hydrogen charging time and current density, the plasticity decreases significantly, and the sensitivity of hydrogen embrittlement increases greatly. The SEM observation results of the fracture morphology show that the fracture type changed from ductile fracture to brittle fracture. As a contrast, under the same conditions, the sensitivity of hydrogen embrittlement of austenitic stainless steel was lower, and the resistance of hydrogen embrittlement was higher. It was found that there was a large amount of hydrogen on the surface of the tested steel after hydrogen charging, and the hydrogen content gradually decreased with the depth of the sample. As hydrogen traps, grain boundaries may affect the hydrogen embrittlement sensitivity of steels.