EVALUATION OF STRESS CORROSION RESISTANCE PROPERTIES OF 15CrMoR(H) IN H2S ENVIRONMENT

To evaluate the hydrogen resistant properties of the 15CrMoR(H) with new smelting process, according to NACE and National Standards, three tests including NACE standard tensile test, NACE standard bent-beam test and hydrogen induced cracking test are executed in saturated hydrogen sulfide(H2S) environment. Stress-life mathematical model of this material is given by analyzing and fitting the results of tensile test. Test results show that the threshold sigma th of tensile test is 0.7R(eL)(252MPa); the threshold nominal stress Sc of bent-beam is higher than 4.5 R-eL (1620MPa); for HIC test, the crack length rate CLR is 4.40%, the crack thickness rate CTR is 0.87% and the crack sensitive rate CSR is 0.04%. Compare with EFC standard, the safety margin of HIC test is 3.4, 3.4 and 37.5 times respectively. All the experimental results show that the new 15CrMoR(H) material has excellent H2S environmental cracking resistance properties.