Many research results show that in the oil and gas field development, containing carbon dioxide containing chromium stainless steel showed excellent corrosion resistance, with the increase of chromium content, the alloy corrosion rate reduced. Generally chromium content reaches 12%, its corrosion resistance is very good, but the presence of chloride, pitting and clearance corrosion will happen. Here are 9 mo, 13 Cr and Cr - 1 22-25Cr duplex stainless steel these three kinds of steel in industrial use, there are two applicable limit data, the first is the application of critical temperature limit: each steel 9 Cr - 1 mo steel is 100 ℃, 13 Cr steel is 150 ℃, 22-25 Cr duplex stainless steel is 250 ℃;The second is a critical point of each steel application of resistance to H2S pressure limit: the 9 Cr - 1 13 Cr mo steel and steel is 0.0001 MPa, the partial pressure of H2S is not higher than 0.0001 MPa, the two steel not happen obvious corrosion resistance decreased; On 22-25 Cr duplex stainless steel is 0.001 MPa. Nickel also can enhance the corrosion resistance of steel, but the effect is not obvious, with 9% nickel steel for high co2 partial pressure of environment, corrosion resistant effect is satisfactory, but occasionally occur cracking and pitting. Containing manganese and nickel corrosion resistance of low alloy steel, manganese steel seems to be more sensitive to pitting.
In addition, in the 175 ℃ and the high chloride environment, alloy, K - 500 also showed good corrosion resistance. If conditions must use carbon steel or low alloy steel, should try to improve the uniformity of microstructure.