黄铜脱锌腐蚀行为特征的电子探针分析

EPMA analysis on corrosion behavior characteristics of brass dezincification

黄铜脱锌作为一种选择性腐蚀现象给生产和生活带来很大的安全隐患。添加一些合金元素可以改善脱锌现象,改善黄铜的耐腐蚀性能。使用岛津电子探针EPMA测试了某种含锡的黄铜,表征了其脱锌腐蚀行为特征,以及添加的合金元素锡的分布特征及其在提高黄铜耐腐蚀性能方面的作用,即脱锌腐蚀首先发生在暴露于基体表面的β相晶粒,然后通过晶界和相界向基体扩散;质量分数约为1%的合金元素锡的加入,可以强化晶界和相界,同时锡在脱锌腐蚀过程中向表面膜迁移,也能抑制脱锌腐蚀的进程,提高耐蚀性能。

As a selective corrosion phenomenon,brass dezincification brings great safety risks to production and life.The addition of some alloying elements can improve the dezincification phenomenon and enhance the corrosion resistance of brass.A kind of brass containing tin(Sn)was tested using Shimadzu Electron Probe Micro-Analyzer(EPMA).The dezincification corrosion behavior was characterized.Meanwhile,the distribution characteristics of the added alloy element(Sn)and its role in improving the corrosion resistance of the brass were also investigated.It was found that dezincification corrosion firstly occurred in theβphase grain exposed to the substrate surface,and then diffused to the matrix through grain boundary and phase boundary.The addition of alloying element(Sn,mass fraction of about 1%)could strengthen the grain boundary and phase boundary.Meanwhile,Sn moved to the surface film during dezincification corrosion process,which could also inhibit this process and improve the corrosion resistance performance.