2种不同形态的Mg-0.12Ca-0.08Ba镁合金的腐蚀行为研究

Corrosion Behavior of Mg-0.12Ca-0.08Ba Magnesium Alloy in Two Different Status

镁合金的应用受到其变形能力差、耐腐蚀性差的制约。为推广镁合金应用,采用低合金化设计并制备了新型Mg-0.12Ca-0.08Ba合金,通过NaCl溶液浸泡试验、SEM、EDS分析和电化学测试等手段考察了其在3.5%NaCl溶液中的腐蚀行为。实验结果表明:随着腐蚀时间的延长,挤压态及挤压退火态Mg-0.12Ca-0.08Ba合金表面由局部点蚀变为大范围面腐蚀,腐蚀产物逐渐增多,腐蚀产物主要为MgO、Mg(OH)2,合金表面的线粗糙度、面粗糙度明显增大,析氢速率逐渐减小。与挤压态镁合金相比,退火态合金析氢速率较慢,开路电位更高,腐蚀电流更小,表明退火态合金耐腐蚀性能较好。

The application of magnesium alloy is limited due to its poor deformation ability and corrosion resistance.In order to extend its application,a novel Mg-0.12Ca-0.08Ba alloy was designed and prepared by low alloying method.The corrosion behavior of the as-prepared alloy in 3.5%NaCl solution was investigated by immersion test in NaCl solution,SEM,EDS analysis and electrochemical test.Results showed that with the increase of corrosion time,the surface of extruded and extruded annealed Mg-0.12Ca-0.08Ba alloy changed from local pitting to large-scale corrosion,and the corrosion products gradually increased.The corrosion products were mainly MgO and Mg(OH)2,the line roughness and surface roughness of the alloy surface increased significantly,and the hydrogen evolution rate decreased gradually.Compared with extruded magnesium alloy,the hydrogen evolution rate of annealed alloy was slower,the open circuit potential was higher,and the corrosion current was smaller,indicating that the corrosion resistance performance of annealed alloy was better.