Effect of Temperature on Corrosion Behavior of 42CrMoE Low-alloy Steel in Boric Acid Solution
Effect of temperature on the corrosion behavior of 42CrMoE low alloy steel in boric acid solution was investigated using electrochemical measurements and immersion tests,taking 42CrMoE steel for fasteners of pressurized water reactor(PWR)primary system as the research object.The results showed that the increase in temperature promotes the anodic dissolution and cathodic reaction process of 42CrMoE steel in boric acid solution,resulting in a decrease in its corrosion resistance.Its corrosion type gradually evolved from uniform corrosion at low temperature to local pitting corrosion at high temper-ature.Moreover,the corrosion rate of 42CrMoE steel increases significantly with the increase of tempera-ture,which is caused by accelerating the corrosion process of boric acid medium and reducing the stabili-ty of corrosion products.In addition,the corrosion rate first decreases and then increases with the elonga-tion of the immersion cycle,and the corrosion rate can reach 1.3 mm/a at 97.5℃.