What is the role of Cu and P elements in 05CuPCrNi steel?

The addition of Cu and P elements to 05CuPCrNi steel is mainly for improving the corrosion resistance and solid solution strengthening of ferrite. Cu is the most important and most commonly used alloying element to improve atmospheric corrosion resistance. The addition of Cu to 05CuPCrNi steel can form a dense thin layer of copper oxide between the corrosion layer of steel and the rich layer of copper, thereby slowing down and inhibiting the medium from continuing to corrode inside the steel plate.

When the Cu content is greater than 0.15%, its resistance to atmospheric corrosion will increase slowly. P is the most effective element in alloying elements to improve atmospheric corrosion resistance. It is an anode depolarizer. In the electrolyte solution, it can accelerate the uniform dissolution of steel and the oxidation rate of iron, and help to form a uniform rust layer on the surface of the steel. , And the boundary with the inner rust layer is obvious, thereby improving the corrosion performance of steel.

The Cu element in the steel is controlled at 0.25%-0.35%, and the lower limit of P is controlled at 0.07%-0.10%, which can meet the requirements of atmospheric corrosion resistance. Cr is also one of the alloying elements that improve the atmospheric corrosion resistance of low-alloy steel, but it generally has a significant effect when the Cu element is combined.