Corrosion Behavior of 304Stainless Steel in High Temperature Naphthenic Acid

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.