采用高温高压反应釜,通过调整介质温度与流速进行高温环烷酸腐蚀试验,研究了304不锈钢在高温条件的腐蚀行为。结果表明,酸值为1.1mg KOH/g时,304不锈钢在240~330 ℃的环烷酸介质中的腐蚀速率随着温度的升高呈现先增后减的变化规律,在275 ℃时腐蚀速率最大,为0.030 8mm?a-1。腐蚀速率与介质流速呈线性递增的关系,从流速为0.85m?s-1时的0.025 8mm?a-1递增到流速为3.4m?s-1时的0.038 5mm?a-1。虽然304不锈钢平均腐蚀速率并不高,但在高温环烷酸环境中点蚀严重,且随着温度升高和流速增大点蚀加剧。故在高温环烷酸介质中不宜使用304不锈钢,对已有的装备应监护使用。

A high pressure autoclave was used to investigate the corrosion behavior of 304stainless steel(SS)underthe condition of high temperature naphthenic acid by adjusting different temperatures and different fluid velocityies.The results show that the corrosion rate of 304SS had a maximum when total acid number(TAN)was 1.1mg KOH/g at 240 ℃ ~330 ℃.The maximum was 0.030 8 mm?a-1 at 275 ℃.And the corrosion rate of this materialincreased linearly with the fluid velocity,from 0.025 8mm?a-1 at 0.85m?s-1 to 0.038 5mm?a-1 at 3.325m?s-1.The results indicate that the average corrosion rate of 304SS was not high,but it had serious pitting corrosion inthe high temperature naphthenic acid environment,and the pitting corrosion intensified as the temperature and thevelocity increased.Therefor 304SS should not be used in the high temperature naphthenic acid medium,and theexisting equipment should be used with guardianship.