HDM钢在AZ91DMg合金液中的腐蚀行为

CORROSION BEHAVIOR OF HOT WORK STEEL CONTAININGHIGH Co IN LIQUID MAGNESIUM ALLOY AZ91D

利用扫描电镜和能谱分析等手段研究了HDM钢在AZ91DMg合金液中的腐蚀行为 .结果表明 ,HDM钢与Mg合金液之间产生了化学反应 ,生成腐蚀产物层 .反应初期 ,腐蚀层疏松 ,基本不具有保护性 ;随着反应的进行 ,腐蚀层逐渐加厚致密 ,具有较好的保护作用 ,减缓了腐蚀速度 .HDM钢与Mg合金液之间的反应主要是在钢中的Fe、Mn、Cr、Co和Mg合金液中的Al、Mn之间进行 ;腐蚀动力学过程可分为快速反应 。

Corrosion behavior of a new hot work die seel containing high Co in liquid magnesium alloy AZ91D was analyzed by SEM and energy spectrum analysis.The results show that a chemical reaction occurred between the steel and liquid magnesium alloy forming a corrosion layer.On the earlier stage of the reaction,the layer was loose and protectiveless;With inreasing of the reaction time,the layer became thick and compact with protectiveness and in tern decreased the reaction rate.Elements such as Fe,Mn etc. in the steel react with elements Al,Mn in liquid magnesium alloy.The corrosion kinetics can be divided into three stages:fast reaction stage,passivating stage and stable reaction stage.