极化电位对5083铝合金型材应力腐蚀行为的影响

The Efects of Polarization Potential on Stress Corrosion Cracking(SCC) Behavior of Aluminum Alloy 5083

摘要: 采用慢应变速率拉伸(SSRT)测试法及扫描电镜(SEM)、能谱仪(EDS)分析手段，研究了不同极化电位对5083铝合金型材应力腐蚀断裂(SCC)行为的影响．结果表明：5083铝合金型材在阴极极化下应力腐蚀指数(Issrt)数值最小，应力腐蚀敏感性最弱，断口为准解理形貌，并伴随有少量韧窝；在阳极极化下Issrt数值最大，应力腐蚀敏感性最强，断口表面分布大量横向裂纹，边缘有明显腐蚀痕迹，微观形貌呈解理状并分布大量穿晶、沿晶裂纹，属于典型脆性断裂特征．5083铝合金型材SCC属于阳极溶解型．

Abstract: The effects of polarization potential on stress corrosion cracking(SCC)behavior of 5083 aluminum alloy are investigated by using slow strain rate tension(SSRT)test，SEM，and EDS．The experimental results reveal that under cathodic polarization the values of SCC susceptibility(Issrt)are minimum，the susceptibility is the weakest，and the fracture is a quasi-cleavage one without a few dipples while under anode polarization the values of Issrt are
maximum，the susceptibility is the s~ongest，lots of transverse cracks exist on the fracture surface，and the edges ale corroded．Moreover，the morphology is cleavage-shaped with lots of transgranular and intergranular cracks，belonging to the brittle fracture．SCC behavior of 5083 aluminum is of anodic dissolution．