沉淀硬化不锈钢FV520B母材及其焊接接头耐蚀性分析

Pitting corrosion resistance of PH stainless steel of FV520B and its welding joint

通过对马氏体沉淀硬化不锈钢FV520B相同热处理条件下的母材及焊接接头满足使用要求后,在35℃下,质量分数为10%的HCl腐蚀介质及相同质量分数下的H2SO4腐蚀介质中的均匀浸泡腐蚀来测定FV520B的耐蚀性.结果表明,在35℃下的不同腐蚀环境中,母材及焊接接头在质量分数为10%的HCl中的腐蚀均较为严重,氯离子对不锈钢的钝化膜有较为严重的破坏性,可在材料的表面形成较深的点蚀坑.在质量分数为10%H2SO4中的腐蚀相对较弱,腐蚀产物也各不相同,且在不同的腐蚀环境中,焊缝处的腐蚀程度比热影响区处的较轻.

The corrosion-resistance of the steel FV520B had been tested respectively in the HCl and H2SO4(10%) under the 35 ℃.The result showed that under the above condition the base metal and the welding welding joint suffered a much more serious pitting corrosion in the HCl(10%) than that in the H2SO4 of the same mass fraction,the chloridion has more serious destructive effect on the passivation film of the stainless steel,which causes the deeper corrosive pitting.while the corrosive effect of 10% mass fraction H2SO4 is relatively inferior,the corrosion products are different either,but under the different corrosive environment,all the corrosive level of the weld joint in the welding point is lower than the HAZ.