等离子体冶炼的N─Cr─Mn钢的耐腐蚀性能

用等离子氮弧冶炼不同氮含量的铬锰不锈钢,其耐腐蚀性能用动电位扫描、电化学阻抗等方法测试,并与1Cr18Ni9不锈钢作比较,结合显微组织分析耐蚀原因。实验结果表明含氮钢的耐蚀性普遍好于1Cr18Ni9不锈钢。随钢中含氮量增加,奥氏体组织扩大,耐腐蚀性能提高。当含氮量达0.74%时形成完全的奥氏体相。经阳极极化后,含氮钢表面的腐蚀层中奥氏体相比原基体的扩大,膜致密,耐腐蚀性能远远高于原基体。

CORROSION RESISTANCE OF N Cr Mn STEEL SMELTED BY USING PLASMA

Various nitrogen containing stainless steels have been smelted by using nitrogen plasma. The corrosion resistances of the steels were measured by electrochemical methods, such as potentiodynamic scanning and electrochemical impetance were compared with 1Cr18Ni9 stainless steel. The experimental results indicated that the N containing stainless steels had much better corrosion resistance than that of 1Cr18Ni9 stainless steel. With increasing the N content in steel, the austenitic phase was enlarged and then the corrosion resistance of the steel increased. When the nitrogen content in steel reached 0.74% , a complete austenitic phase in steel was formed. After anodization, the austenitic phase in corroding layer on steel surface was larger than in original bright surface, and then a compact film was formed.