稀土处理对Mn-V-Ti钢点蚀性能影响的研究

实验室冶炼了5炉稀土处理及未处理的锰系低合金船体钢,并收集了一种工业生产的同种钢。通过冶金分析、极化试验、闭塞电池试验及挂片试验,研究了夹杂物变性对钢材点蚀诱发及扩展的影响;结果表明:钢中夹杂物是点蚀的诱发源,硫化物夹杂物的数量对钢材的点蚀性能有显著影响。稀土硫化物夹杂数量少,体积小,能显著降低钢的点蚀诱发敏感性,降低钢的蚀坑扩展速度,提高钢的耐蚀性。

Effect of the Rare Earth Treatment on Pitting Corrosion Behavior of Mn-V-Ti-steel

Five pots of low alloy ship hull Mn-steel with and without rare earth treatment were made in laboratory,and a commercial manufactured Mn-steel with RE treatment was collected.The influence of the modification of inclusion on the pit initiation and pit propagation of the steel was studied by means of metallurgy analysis,polarization test,occluded corrosion cell(OCC)test and coupon test.The results suggested that the inclusions in the steel are main sites for pit initiation,and the resistance against pitting corrosion of steels is strongly affected by the magnitude of the sulfide inclusions.Less and fewer RE-sulfide multi-phase inclusion heavily decreases pitting susceptibility and rate of pit propagation,which improves the resistance of the steel to corrosion.