冷变形对304奥氏体不锈钢组织及氢脆敏感性的影响

Effect of Cold Deformation on Microstructure and Hydrogen Embrittlement Sensitivity of 304 Austenitic Stainless Steel

304奥氏体不锈钢是储氢的候选材料,其在冷变形过程中的氢脆敏感性存在争议。本文研究固溶态和两种冷变形状态下304奥氏体不锈钢的微观组织和氢脆敏感性。结果表明:与固溶态的相比,冷轧304不锈钢产生了应变诱导马氏体及变形位错,强度增加,氢脆敏感性也增加;冷轧变形量越大,马氏体含量越多,强度越高,氢脆敏感性也越高。冷变形和充氢共同导致304不锈钢断裂模式改变,固溶态和冷轧态的试验钢充氢前均为韧性断裂,固溶态充氢后为解理和准解理脆性断裂,冷轧态充氢后为沿晶断裂并有二次裂纹。

The 304 austenitic stainless steel is a candidate material for hydrogen storage,its hydrogen embrittlement sensitivity during cold deformation is controversial.The microstructure and hydrogen embrittlement sensitivity of 304 austenitic stainless steel in solid solution state and two cold deformation states were studied.The results show that compared with those of the solid state,the strain induced martensite and deformed dislocation are produced in the cold-rolled 304 stainless steel,the strength increases and the hydrogen embrittlement sensitivity increases.The greater the cold rolling deformation,the more martensite,the higher the strength,the higher the hydrogen embrittlement sensitivity.The cold deformation and hydrogen filling cause the fracture mode change of 304 stainless steel.Both the solid solution and the cold rolled test steels are ductile fracture before filling hydrogen,the solution steel is cleavage and quasi cleavage brittle fracture after hydrogen charging,and the cold rolled steel is intergranular fracture and has secondary crack after hydrogen charging.