钢-铝异种金属自冲铆接头酸性环境下的失效行为分析

Failure behavior analysis of self-piercing riveted joints of steel-aluminum dissimilar metal under acidic environment

以摩尔浓度为0.02 mol/L的NaHSO_3溶液为腐蚀溶液进行钢(DP590)-铝(AA5052)异种金属自冲铆试件干湿周浸腐蚀试验,通过腐蚀动力学和静力学测试,研究自冲铆接头在酸性腐蚀环境下的静强度,并分析接头失效机理。结果表明:随腐蚀周期的延长,试件质量损失和腐蚀速率均呈先增大后减小趋势,板材与铆钉腐蚀程度不断加重;试件接头失效形式主要有3种(L、M和N形),其对试件静强度影响较大,M形失效试件静强度值远大于其他两种;失效位移对试件能量吸收值影响显著,M形失效试件能量吸收值最小。

Cyclic wet-dry immersion corrosion test of self-piercing riveted(SPR)specimens of steel(DP590)-aluminum(AA5052)dissimilar metal was carried out with 0.02 mol/L NaHSO3 solution as corrosion solution.The SPR joints were studied by corrosion kinetics and statics tests.The static strength of the SPR joints in acid corrosive environment was studied,and the failure mechanism of joints was analyzed.Corrosion test results show that the weight loss and corrosion rate of the specimens increase first and then decrease with the increase of corrosion cycle,and the corrosion degree of the sheets and rivets is increasing.In the static test,the failure modes of the specimen joints are mainly three kinds(L,M and N shape),which have a great influence on the static strength of the specimens.The static strength of the test piece in the M-shaped failure mode is much higher than that in two other failure modes.The failure displacement has a significant effect on the energy absorption value,the test piece joint in the M-shaped failure mode has the smallest energy absorption value.