固溶时效处理对TB5钛合金组织和电化学腐蚀行为的影响

针对海洋石油钻探和管线用TB5钛合金的耐电化学腐蚀性能优化，研究了常规固溶和时效热处理对其电化学腐蚀行为的影响。试验结果显示，随着固溶温度的提高，TB5钛合金的晶粒尺寸逐渐变大，950 ℃固溶处理比800 ℃固溶处理后的尺寸增大了125 μm，固溶温度越低晶粒尺寸越小其耐腐蚀性能越好；时效后合金的耐腐蚀性能显著提升，随着时效温度的升高，次生α相的含量呈现先上升后下降的趋势，合金耐腐蚀性能与次生α相含量成正比。研究表明，耐电化学腐蚀性能最优的热处理工艺是800 ℃固溶+500 ℃时效，腐蚀速率为1.44×10-3 mm/a。

Effect of Solution Aging Treatment on Electrochemical Corrosion Behavior of TB5 Titanium Alloy

Aiming at the optimization of electrochemical corrosion resistance of TB5 titanium alloy for offshore oil drilling and pipeline, the effects of conventional solid solution and aging heat treatment on its electrochemical corrosion behavior were studied. The results show that the grain size of TB5 titanium alloy increases gradually with the increase of solution temperature. The grain size of 950 ℃ solution treatment is 125 μm larger than that of 800 ℃. The lower the solution temperature is, the smaller the grain size is, and the better the corrosion resistance is. The corrosion resistance of the alloy is significantly improved after aging. The secondary phase α content increased first and then decreased with the increase of aging temperature. The corrosion resistance of the alloy are proportional to the content of the secondary phase α. The best treatment process of the electrochemical corrosion resistance is 800 ℃ solid solution + 500 ℃ aging, and the corrosion rate is 1.44 ×10-3 mm/a.