船舶用Ti70合金在人工海水中的腐蚀行为研究

采用全浸腐蚀和电偶腐蚀实验，研究了Ti70合金的均匀腐蚀行为，以及与945钢的电偶腐蚀行为。结果表明：Ti70合金耐蚀性能极好，在60 ℃人工海水浸泡30 d后试样出现了轻微增重，腐蚀速率为-5.857×10^-4 mm/a，达到了I级完全耐蚀级别；Ti70合金自腐蚀电位远高于945钢，两者偶联时945钢将作为阳极被加速腐蚀；随着Ti70/945钢偶对面积比增加，945钢质量损失、以及电偶腐蚀电流和电偶腐蚀系数均逐渐增加，当两者偶对面积比为1∶1时，电偶腐蚀敏感等级达到了D级，因此当Ti70合金与945钢接触使用时需对945钢进行阴极保护。

Corrosion Behavior of Marine Ti70 Alloy in Artificial Seawater

The corrosion behavior of a marine Ti70 alloy and galvanic corrosion behavior of the couple of Ti70 alloy with 945 steel were investigated in artificial sweater via immersion- and galvanic corrosion-test. Results showed that Ti70 alloy presented excellent corrosion-resistance up to grade 1. The weight of the Ti70 alloy increased slightly after immersed in the artificial seawater at 60 ℃ for 30 d and its corrosion rate was only -5.857×10^-4 mm/a. The free corrosion potential of 945 steel was more negative than that of Ti70 alloy and the corrosion of steel was accelerated when coupled with Ti70 alloy. The mass loss of 945 steel, corrosion current and galvanic corrosion coefficient increased with the increase of the area ratio of Ti70 alloy to 945 steel, while its sensitivity of galvanic corrosion reached D-level when the area ratio was 1∶1. Therefore, properly cathodic protection was necessary for 945 steel when coupled with Ti70 alloy.