热暴露温度和氢对Ti811合金热盐应力腐蚀性能的影响

Effect of Exposure Temperature and Hydrogen on the Hot Salt Stress Corrosion of Ti811 Alloy Rod

研究了热暴露温度和氢对Ｔｉ８１１合金棒材热盐应力腐蚀（ＨＳＳＣ）性能的影响。结果表明：Ｔｉ８１１合金ＨＳＳＣ性能对暴露温度敏感，在暴露温度低于４２５℃时，合金无ＨＳＳＣ现象，高于４８０℃时，合金发生明显ＨＳＳＣ，性能恶化。合金发生ＨＳＳＣ的临界温度为４５０℃。在ＨＳＳＣ过程中有氢产生，氢优先沿晶界扩散，盐蚀区氢和氧含量高于基体，使材料脆化．

The effects of exposure temperature and hydrogen on the hot salt stress corrosion (HSSC) of Ti811 alloy rod have been studied. The results suggest that its HSSC properties are sensitive to exposure temperature. The alloy has no HSSC phenomenon if the hotsalt exposure temperature is lower than 425℃. If the temperature is higher than 480℃, the alloy has obvious HSSC and its Properties worsen greatly. The critical exposure temperature of HSSC is 450℃. Nascent hydrogen was generated and selectively diffused into the metallic substrate along grain boundary during HSSC process. The contents of hydrogen and oxygen in salt corrosion zone are higher than that in matrix, which resulting in embrittlement.