冶金因素对钢点蚀扩展的影响

Effect of metallurgical factors on the susceptibility to pitting initiation in steels

选择六种冶金因素各有特点的低碳钢和一种低合金钢,通过模拟闭塞腐蚀电池实验,结合冶金特点和腐蚀形貌分析,研究冶金因素对孔蚀扩展的影响.结果表明,钢中固溶氧量、夹杂物、钙处理、磷含量及其偏析和合金元素镍铬等对点蚀扩展有重要影响.钢中固溶氧量高、钙处理、高磷量和高镍铬量有利于抑制蚀坑扩展.

The pitting propagations of six low-carbon steels and one low-alloy steel with representative metallurgical characteristics were compared by means of occluded corrosion cell （OCC） stimulation test. Combined their metallurgical characteristic with corrosion appearance, the effect of metallurgical factors on the pitting propagation was researched. The results show that dissolved oxygen, inclusions, calcium treatment, phosphorus content and phosphoric segregation, and Ni and Cr elements in steels have important influ- ence on the pitting propagation. A higher amount of dissolved oxygen, phosphorus, Ni and Cr elements, and calcium treatment are beneficial to restraining pitting propagation.