低碳钢的点蚀诱发敏感性研究

选择 3种冶金因素有代表性的低碳钢 ,通过极化试验比较了它们之间的点蚀诱发敏感性 ,同时利用电子探针分析了不同夹杂物在诱发点蚀过程中的腐蚀特征 ,并利用Flade电位比较了不同钢之间的钝化膜稳定性的差异 .结果表明 :沸腾钢的点蚀诱发敏感性显著低于镇静钢 ,稀土处理镇静钢则介于两者之间 ;夹杂物是钢中主要点蚀诱发源 ,钢基体与夹杂物交界处的钝化膜保护作用最弱 ,点蚀均从该处诱发 ;同类夹杂物在不同类型钢中的点蚀诱发敏感性差异较大 ,同一钢中的不同类型夹杂物的点蚀诱发敏感性差异很小 ,硫化物夹杂较其它夹杂物的点蚀诱发敏感性稍强 .

A comparison of pitting susceptibility in low carbon steels

Three low carbon steels with different metallurgy factors have been selected. Their susceptibility to pitting has been compared by means of polarization test, and pitting characteristics of different inclusions during pitting initiation have been studied with the EPMA, and their passivation films stabilization has been compared by means of Flade measurement. The results show that the susceptibility of boiling steel to pitting initiation is markedly lower than those of killed steel, the pitting susceptibility of killed steel treated by rare earth is between boiling steel and killed steel. The inclusions are the most source susceptible to pitting initiation. Passivation film of boundary between steel matrix and inclusions is the weakest, and the early pitting corrosion is caused from here. The difference of susceptibility of pitting initiated by homogeneous inclusions is large when these inclusions existed in different kind of steels. The difference of susceptibility to pitting initiated by different inclusions in the same steel is small, and the sulfide inclusions have bigger ability in initiating pitting than other types of inclusions.