Effects of Cu and P Elements on 05CuPCrNi

The main purpose of adding C, and P to 05CuPCrNi is to improve the corrosion resistance and solid solution strengthen ferrite.

Cu is the most important and most commonly used alloying element to improve atmospheric corrosion resistance. Adding Cu to 05CuPCrNi steel can form a dense copper oxide thin layer between the corrosion layer of the steel and the copper-rich accumulation layer, thereby slowing down and inhibiting the corrosion of the medium continue to corrode to the inside of 05CuPCrNi steel plate. When the Cu content is greater than 0.15%, its anti-atmospheric corrosion performance improves slowly.

P is the most effective element in improving atmospheric corrosion resistance among alloying elements, it is an anode depolarizer. In the electrolyte solution, it can accelerate the uniform dissolution of 05CuPCrNi steel and the oxidation rate of iron, which helps to form a uniform rust on the steel surface. And the boundary with the inner rust layer is obvious, thereby improving the corrosion performance of 05CuPCrNi steel. Cu in the steel is controlled at 0.25%-0.35%, and the lower limit of P is controlled at 0.07%-0.10%, so that can meet the requirements of atmospheric corrosion resistance.