Ti35合金焊接接头在高温硝酸中的腐蚀性能研究

以沸腾的核乏燃料后处理模拟料液及空白硝酸溶液为腐蚀液,研究了Ti35合金焊接接头的耐腐蚀性能。在模拟料液中对Ti35合金熔敷金属及焊接热模拟样进行全浸腐蚀实验,间接评价了焊接接头熔区及热影响区的耐腐蚀性能。结果表明:Ti35合金焊接接头在沸腾空白硝酸溶液及模拟料液中均具有良好的均匀腐蚀性能,焊缝熔区及热影响区的腐蚀速率大于焊接接头的腐蚀速率,焊接接头的腐蚀对焊接应力的敏感性不高;在沸腾空白硝酸介质中,硝酸浓度对焊接接头的耐蚀性能有较大的影响,随硝酸浓度的提高,焊接接头的耐蚀性能有所下降;硝酸溶液中氧化性金属阳离子对Ti35合金的焊接接头具有缓蚀作用。

Research on Corrosion Behavior of Ti35 Alloy Welding Joint in High Temperature Nitric Acid

In this paper, the corrosion of Ti35 alloy welding joints was investigated in boiling simulated solution of reprocessing and blank nitric acid. The corrosion resistance was evaluated indirectly by deposited metal and welding thermal simulation sample immersed in simulated solution. The tests show that the welding joints of Ti35 alloy display excellent uniform corrosion behavior in boiling simulated solution of reprocessing and blank nitric acid. The corrosive rates of molten zone and heat - affected zone are higher than that of matrix. The corrosion of welding joints is found to be insensitive to the welding stress. In the different concentration of nitric acid solution, with concentration increased, the corrosive rate of joints is evidently accelerated. The metal ion existed in solution can inhibit corrosion of welding joints of Ti35 alloy.