N08825/L450MS复合管焊缝组织性能及抗腐蚀特性研究

为了解决油田严苛服役条件下管材的耐腐蚀问题,采用拉伸试验、夏比冲击试验、DWTT、弯曲试验、硬度测试、金相分析以及晶间腐蚀试验、HIC试验、SSCC试验等方法 ,对Φ610 mm×20.5(3+17.5)mm规格N08825/L450MS双金属复合管焊缝的力学性能、微观组织和耐腐蚀性能进行了研究。结果表明,试验焊缝的各项力学性能均满足相关标准要求;覆层焊缝中心区金相组织呈等轴状树枝晶形态,边缘呈柱状树枝晶形态,均为奥氏体+铁素体;复合管覆层母材和焊缝抗晶间腐蚀和点蚀性能优良,基层母材及焊缝对HIC和SSCC不敏感,可满足含有H2S和CO2等强腐蚀油气介质的集输要求。

Research on Weld Microstructure and Corrosion Resistance Property of N08825/L450MS Composite Pipe

In order to solve the corrosion resistance problem of tubular goods under harsh service conditions,by adopting tensile test,Charpy impact test,DWTT,bend test,hardness inspection,metallographic analysis,intergranular corrosion test,HIC test,SSCC test and so on,the weld performance of Φ610 mm×20.5(3+17.5) mm N08825/L450MS bimetal composite pipe were studied,including mechanical properties,microstructure and the corrosion resistance.The results indicated that the mechanical properties of the test weld meet the relevant standard requirements,the metallographic structure of the cladding weld center zone presents equiaxial dendritic crystal,and the edges are columnar dendrites,both are austenitic and ferritic.Intergranular corrosion resistance and pitting performance of composite pipe coating material and weld are excellent,the base metal and welds are insensitive to HIC and SSCC,which can meet the gathering requirements of strong corrosive oil and gas media containing H2S and CO2.