固溶时效处理对AZ31-0.6Sr镁合金腐蚀性能的影响  

Effects of Solution and Aging Treatment on Corrosion Resistance of AZ31-0.6Sr Alloy

作　　者：刘军威[1] 彭晓东[1,2] 刘明朴[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400044

出　　处：《热加工工艺》2011年第6期140-142,201,共4页Hot Working Technology

基　　金：国家973项目资助(2007CB613702)

摘　　要：采用盐水浸泡试验研究了铸态(F)、500℃固溶(T4)和250℃时效16 h(T5)的AZ31-0.6Sr镁合金在w(NaCl)=3.5%溶液中的腐蚀行为。结果表明,铸态镁合金耐腐蚀性能最差,T5态耐腐蚀性能有所提升,T4态合金耐腐蚀性能最好。合金腐蚀速率随热处理状态的变化与其微观组织有关,铸态合金中的富Sr化合物能与基底α相构成电偶腐蚀而加剧合金腐蚀;T5态下出现了连续分布的β相能在一定程度上起腐蚀阻挡层作用,降低合金腐蚀速率。The corrosion behavior of AZ31-0.6Sr alloy as-cast（F）, solution treated （T4） at 500 ℃ and aged at 250 ℃ for 16 h was investigated in 3.5%NaCl solution by immersion test. The results show that the alloy as-solution has the lowest corrosion rate, and the alloy as-cast exhibites the highest corrosion rate. The dependence of the corrosion rate of the alloy on heat treatment can be related to the change of its microstructure. The Sr-rich compound in cast alloy can induce galvanic corrosion with the adjacent matrix and thereby accelerate the corrosion process. The precipitation of coarse 13 phase can act as a barrier to some extent and cause a decrease of the corrosion rate.

关 键 词：腐蚀 时效 固溶 镁合金 极化曲线 

分 类 号：TG156.92[金属学及工艺—热处理]