国产X70管线钢与焊接接头组织及SSCC性能  

Microstructures and SSCC Properties for Base Metals and Welding Joints of Domestic X70 Pipeline Steels

作　　者：李云涛[1] 杜则裕[1] 陶勇寅[1] 李建军[1] 

机构地区：[1]天津大学材料科学与工程学院,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2005年第3期274-278,共5页Journal of Tianjin University：Science and Technology

摘　　要：输气管道的服役条件多为潮湿环境,输送介质含H2S.随着国产X70管线钢在西气东输工程中的应用,国产高强度管线钢硫化物应力腐蚀开裂(SSCC)性能研究显得尤为重要.为此,测试、分析了国产X70管线钢及其焊缝的组织,进一步采用慢应变速率法(SSRT)研究了H2S对国产X70管线钢及其焊接接头SSCC的影响,国产X70管线钢及其焊接接头在含H2S腐蚀介质中应力腐蚀敏感性随H2S浓度的增加而增加,在H2S质量分数为50×10-400时,母材的脆性系数为19. 9500,焊缝的脆性系数高达59. 1900.若以2500视为安全值,则在H2S浓度为50×10-40时的母材就SSCC而言是安全的,而焊缝却是不安全的.With the application of domestic X70 pipeline steels in the project of “gas transmitting from west to east”, they mostly serve in wet environments with H_2S. In order to prevent pipeline steels from more loss in advance of cracking, the study on sulfide stress corrosion cracking (SSCC) properties for domestic X70 pipeline steels became more and more important. Therefore microstructures of base metals and welds were tested and analyzed, and slow strain rate test (SSRT) was further adopted to study the resistance of SSCC of X70 steels and welding joints, the effect of content of H_2S on corrosion properties of pipeline steels was discussed. The results revealed that with the increasing of H_2S concentration, resistance of SSCC would increase. When H_2S concentration was 50×10^(-4)~0_0, brittleness coefficient of base metal was 19.95~0_0,and brittleness coefficient of welding joint was 59.19~0_0. As far as SSCC was considered, if it was assumed safe value when brittleness coefficient was 25~0_0, domestic X70 steel base metals were safe ,while its welding joints were not in the medium with 50×(10^(-4)~0_0 )H_2S concentration.

关 键 词：国产X70管线钢 焊接接头 组织 硫化氢 硫化物应力腐蚀开裂 

分 类 号：TG142[一般工业技术—材料科学与工程] TG457.6[金属学及工艺—金属材料]