变形对汽车用铁素体不锈钢微观组织及抗氢性能的影响

Effect of Deformation on Microstructure and Hydrogen Resistance of Ferritic Stainless Steel for Automobile

铁素体不锈钢(FSS)具有良好的成形性能、低成本和耐腐蚀性能,被广泛应用于汽车制造等行业。本文通过对退火态、轧制20%、轧制40%的AISI430铁素体不锈钢进行4 h的电化学充氢,研究了变形对汽车用AISI430铁素体不锈钢组织性能的影响和氢脆断裂机理。轧制态铁素体不锈钢具有较高的氢脆敏感性,氢对材料力学性能影响显著,随着变形量的增大,氢脆敏感性增加;通过EBSD对三种组织进行分析,随着变形量的增大,组织中没有发生相变,但是晶粒由等轴状变成扁平伸长状,晶粒变形比例增大,KAM值增大,位错密度增大;通过TDS检测,变形量越大氢含量越多,低温峰越高。

Ferritic stainless steel(FSS)has good formability, low cost and corrosion resistance. It is widely used in automobile manufacturing and other industries. The effect of deformation on the microstructure and properties of AISI430 ferritic stainless steel for automobile and the mechanism of hydrogen embrittlement fracture were studied by electrochemical hydrogen charging for 4 hours. Rolled ferritic stainless steel has high hydrogen embrittlement sensitivity, and hydrogen has a significant effect on the mechanical properties of the material. With the increase of deformation, the hydrogen embrittlement sensitivity increases. EBSD was used to analyze the three structures. With the increase of deformation, there was no phase transformation in the structure.However, the grain changes from equiaxed to flat elongated, the grain deformation ratio increases, the KAM value increases, and the dislocation density increases. Through TDS detection, the greater the deformation, the more hydrogen content and the higher the low-temperature peak.