不同海域Custom450高强度不锈钢的腐蚀规律研究

目的 研究Custom450钢在青岛、舟山、厦门及三亚等4个海域大气和飞溅环境中的自然腐蚀规律。方法 采用形貌分析、腐蚀速率、点腐蚀深度分析等方法对Custom450钢在上述4个海域大气和飞溅区的腐蚀规律进行研究。结果 Custom450钢在4个海域大气环境的年平均腐蚀速率相当，且未观察到有点蚀现象发生，舟山海域的年平均腐蚀速率最小，为0.001 41 mm/a，三亚海域的年平均腐蚀速率最大，为0.001 54 mm/a。4个海域飞溅区的年平均腐蚀速率范围为0.0021～0.0028mm/a，舟山海域的年平均腐蚀速率为0.002 1 mm/a，平均及最大点腐蚀深度分别为5.7μm和25.99μm，均低于其他3个海域。结论 Custom450钢在4个海域的大气环境暴露1 a后，未发现明显的腐蚀现象，表明该钢短期内在上述4个海域海洋大气环境中具有良好的耐蚀性。在飞溅环境中的腐蚀速率高于大气环境，且有明显的点腐蚀现象发生，钢中未溶的NbC相会促进点腐蚀现象的发生。

Corrosion Law of Custom450 High Strength Stainless Steel in Different Sea Areas

The work aims to study the natural corrosion law of Custom450 steel in the atmosphere and splash environment of Qingdao, Zhoushan, Xiamen and Sanya sea areas. The corrosion law of Custom450 steel in the above four sea areas was studied by means of morphology analysis, corrosion weight loss and pitting corrosion depth analysis. The average annual corrosion rate of Custom450 steel in the atmospheric environment of the four sea areas was similar and no pitting corrosion was observed. The average annual corrosion rate in Zhoushan sea area was 0.001 41 mm/a, and the average annual corrosion rate in Sanya sea area was 0.001 54 mm/a. The average annual corrosion rate in splash zone of the above four sea areas ranged from 0.002 1mm/a to 0.002 8 mm/a. The average corrosion rate and the average and maximum point corrosion depth in Zhoushan Sea area were 0.002 1 mm/a, 5.7 μm and 25.99 μm, respectively, which were lower than those in other three sea areas. No obvious corrosion is found after 1 year of exposure, which indicates that Custom450 steel has good corrosion resistance in the atmosphere and splash environment of the above four sea areas in the short term, and the undissolved NbC phase in steel promotes the occurrence of pitting corrosion.