In order to ensure that the mechanical properties such as yield strength, tensile strength, elongation and hardness of various stainless steel coils meet the requirements, stainless steel coils must undergo heat treatments such as annealing, solution treatment, and aging treatment before delivery. The corrosion resistance of stainless steel coils mainly depends on its alloy composition (chromium, nickel, titanium, silicon, aluminum, etc.) and the internal structure of stainless steel coils, and the main role is chromium. Chromium has high chemical stability and can form a passivation film on the steel surface to isolate the metal from the outside world, protect the steel coil from oxidation, and increase the corrosion resistance of the steel coil. After the passivation film is destroyed, the corrosion resistance decreases.

Stainless steel coil surface marks and corresponding features

Corrosion resistance of 321 stainless steel

The high-temperature uniform corrosion and electrochemical corrosion behavior of 321 stainless steel in uranyl nitrate solutions with different concentrations and pH VALUES (were studied by weighing method and electrochemical method.

The results of the uniform corrosion test show that under the selected corrosion conditions, the surface finish of the 321 stainless steel sample has no obvious change within 960 hours, the corrosion rate is less than 0.04g/m2, and it is resistant to corrosion in low acidity uranyl nitrate solution.

The corrosion electrochemical characteristics of 321 stainless steel in uranyl nitrate solution with dissolved oxygen were studied by corrosion electrochemical method, and the corrosion potential and corrosion current density of the electrode were measured. After analysis, there is a certain amount of uranium in the corrosion film of the sample after electrochemical corrosion, and the thickness of the corrosion film containing uranium is 10~15nm according to the depth analysis.

Stainless steel grade comparison table