X90大口径UOE焊管的开发研究

Research and development of X90 large diameter UOE welded pipes

采用热—力模拟试验技术和试验轧制方法,研究了X90高强度管线钢形变奥氏体动态连续冷却转变特性以及工艺性能关系,并以此为基础进行了X90管线钢板和大口径焊管的工业试制。结果表明,通过采用低碳、高锰及微合金化的成分设计方法和优化的控轧控冷厚板制造工艺,可制造以细化低碳贝氏体为组织特征、具有高强度和高韧性的X90管线钢板。结合合适的UOE成型及焊接工艺,试制的1 219×16.3 mm、1 219×19.6 mm规格X90大口径UOE焊管同样具有优异的强度、塑性和韧性匹配,管体横向均匀延伸率达到4.5%以上,-10℃管体冲击功达到300 J以上,0℃DWTT剪切面积达到90%以上,且具有较好的焊缝质量,各项性能指标均满足第44版API 5L标准要求。

By using the thermal mechanical simulation technology and pilot rolling method, the features of continuous cooling phase transformation of deformed austenite and the relationship between processing parameters and mechanical properties for X90 high strength pipeline steel were researched, and X90 heavy plates and large diameter welded pipes were trial produced. The results show that by the adoption of a micro-alloyed composition design with low carbon and high manganese and optimized TMCP （Thermo-Mechanical Control Process ）parameters, high strength and high toughness X90 plates with low carbon fine bainite microstructure can be produced. After being processed with appropriate UOE forming and welding techniques, the trial produced X90 UOE pipes with dimensions of （φl 219 x 16.3 mm and 4）1 219 × 19.6 mm had a good combination of strength, toughness and plasticity. The transverse tensile uniform elongation of the pipe body was over 4.5 %. The Charpy-V impact energy at - 10℃ was over 300 J and the DWTF （ Drop Weight Tear Test） shear area ratio at 0℃ was over 90%. Good weld seam qualities were also obtained. All of the mechanical properties and pipe geometry well satisfied the requirements of the 44th API 5L specification.