Variation and degradation of P-110 casing steel mechanical properties, due to sulfide stress cracking （SSC） in sour environments, was investigated using tensile and impact tests. These tests were carried out on spec...Variation and degradation of P-110 casing steel mechanical properties, due to sulfide stress cracking （SSC） in sour environments, was investigated using tensile and impact tests. These tests were carried out on specimens, which were pretreated under the following conditions for 168 hours： temperature, 60 ℃; pressure, 10 MPa; H2S partial pressure, 1 MPa and CO2 partial pressure, 1 MPa; preload stress, 80% of the yield strength （os）; medium, simulated formation water. The reduction in tensile and impact strengths for P-110 casing specimens in corrosive environments were 28% and 54%, respectively. The surface morphology analysis indicated that surface damage and uniform plastic deformation occurred as a result of strain aging. Impact toughness of the casing decreased significantly and intergranular cracking occurred when specimens were maintained at a high stress level of 85% %.展开更多
The sulfide stress corrosion(SSC)behaviors of the high strength low alloy steel at the different temperatures were investigated by the microstructural observation and electrochemical noise(EN)analysis.With the corrosi...The sulfide stress corrosion(SSC)behaviors of the high strength low alloy steel at the different temperatures were investigated by the microstructural observation and electrochemical noise(EN)analysis.With the corrosion temperature increasing from 20 to 40℃,SSC ruptured time is prolonged.The increase in corrosion temperature results in the decrease of the saturation solubility of H_(2)S in the solution and thus increases pH value of solution.The increase in corrosion temperature decreases the size of the holes and cracks in the corrosion product film on the surface of the sample,which is due to the formation of the dense FeS corrosion product film.The current kurtosis results indicate that the time for the first occurrence of crack initiation is postponed by the increase in the corrosion temperature.The standard deviation of current noise signals,current kurtosis,power spectral density and energy distribution plot results shows a great consistency,which suggests that EN analysis method can reflect SSC behaviors in real time.展开更多
采用NACE三点弯曲法和NACE standard TM 0284-2003氢致开裂标准实验方法,通过SEM、TEM、EDS等手段研究了鞍钢生产的X70级管线钢的硫化物应力腐蚀开裂(SSCC)和氢致开裂(HIC)行为。研究表明,鞍钢生产的X70级管线钢具有较好的抗SSCC&HI...采用NACE三点弯曲法和NACE standard TM 0284-2003氢致开裂标准实验方法,通过SEM、TEM、EDS等手段研究了鞍钢生产的X70级管线钢的硫化物应力腐蚀开裂(SSCC)和氢致开裂(HIC)行为。研究表明,鞍钢生产的X70级管线钢具有较好的抗SSCC&HIC性能;以均匀细小的针状铁素体为主的显微组织具有优良的抗SSCC&HIC性能;针状铁素体内高密度缠结的位错和碳氮化物在位错网络上的沉淀析出是针状铁素体钢具有优良的抗SSCC&HIC性能的主要原因。展开更多
基金support of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University in Chinathe National Natural Science Foundation of China (Grant No.51004084)
文摘Variation and degradation of P-110 casing steel mechanical properties, due to sulfide stress cracking （SSC） in sour environments, was investigated using tensile and impact tests. These tests were carried out on specimens, which were pretreated under the following conditions for 168 hours： temperature, 60 ℃; pressure, 10 MPa; H2S partial pressure, 1 MPa and CO2 partial pressure, 1 MPa; preload stress, 80% of the yield strength （os）; medium, simulated formation water. The reduction in tensile and impact strengths for P-110 casing specimens in corrosive environments were 28% and 54%, respectively. The surface morphology analysis indicated that surface damage and uniform plastic deformation occurred as a result of strain aging. Impact toughness of the casing decreased significantly and intergranular cracking occurred when specimens were maintained at a high stress level of 85% %.
基金the National Natural Science Foundation of China(Grant Nos.51975404,52034004 and 52171123)for grant and financial support.
文摘The sulfide stress corrosion(SSC)behaviors of the high strength low alloy steel at the different temperatures were investigated by the microstructural observation and electrochemical noise(EN)analysis.With the corrosion temperature increasing from 20 to 40℃,SSC ruptured time is prolonged.The increase in corrosion temperature results in the decrease of the saturation solubility of H_(2)S in the solution and thus increases pH value of solution.The increase in corrosion temperature decreases the size of the holes and cracks in the corrosion product film on the surface of the sample,which is due to the formation of the dense FeS corrosion product film.The current kurtosis results indicate that the time for the first occurrence of crack initiation is postponed by the increase in the corrosion temperature.The standard deviation of current noise signals,current kurtosis,power spectral density and energy distribution plot results shows a great consistency,which suggests that EN analysis method can reflect SSC behaviors in real time.
文摘采用NACE三点弯曲法和NACE standard TM 0284-2003氢致开裂标准实验方法,通过SEM、TEM、EDS等手段研究了鞍钢生产的X70级管线钢的硫化物应力腐蚀开裂(SSCC)和氢致开裂(HIC)行为。研究表明,鞍钢生产的X70级管线钢具有较好的抗SSCC&HIC性能;以均匀细小的针状铁素体为主的显微组织具有优良的抗SSCC&HIC性能;针状铁素体内高密度缠结的位错和碳氮化物在位错网络上的沉淀析出是针状铁素体钢具有优良的抗SSCC&HIC性能的主要原因。
