Hydrogen Induced Stress Cracking Susceptibility of 22Cr Duplex Stainless Steel Used in Deep Sea Oil and Gas Facilities

Using corrosion electrochemical methods, four-point bending and slow strain rate tests, the effects of cathodic potential, applied stress and hydrogen content on the hydrogen-induced stress cracking sensitivity of 22Cr duplex stainless steel commonly used in deep-sea oil and gas facilities were studied. The results showed that the hydrogen evolution reaction of 22Cr duplex stainless steel in seawater significantly accelerated when the cathodic protection potential was negative than -990 mV (vs. SCE, the same below). With the negative shift of the cathodic protection potential and the increase of the applied stress, the hydrogen embrittlement sensitivity of 22Cr duplex stainless steel increased. When the tensile stress exceeded 95%σ_0.2, hydrogen-induced cracking might occur at a negative potential of -1 150 mV. Under 98%σ_0.2 loading condition, when the hydrogen content of duplex stainless steel reached 10.6-12.6 mg/L, hydrogen-induced cracking might be induced.