Abstract：Combined with the SEM, the corrosion behavior of 439 ultra- pure ferritic stainless steel and 430 ferritic stainless steel has been compared by salt spray test, electrochemical test, FeCl3 point corrosion test. The result shows the pitting corrosion resistance of 439 ultra- pure ferritic stainless steel with extremely low carbon and nitrogen gap elements is better than that of 430 ferritic stainless steel. Although the capability of 430 passive film repair is stronger, the rate of pitting corrosion is faster. And 430 stainless steel has severe intergranular corrosion sensitivity, while 439 stainless steel is slightly lighter. Loop salt spray test shows that 430 stainless steel suffers severe corrosion, and 439 ultra- pure ferritic stainless steel has less corrosion. Therefore, on the basis of general 430, reducing the content of interstitial element carbon and nitrogen and adding the stabilizing element Ti can improve the corrosion resistance greatly.
2018, Vol. 28 
