X90钢级大直径螺旋埋弧焊管的研制

为了响应管道建设向高强度、高压力的发展趋势，采用低C、高Mn和Mo-Cr-Ni-Cu-Nb-Ti合金设计体系和控轧控冷技术，开发出以粒状贝氏体为主，辅之少量板条状贝氏体铁素体的X90管线钢。通过对低应力成型技术及焊接技术等制管工艺的研究，成功开发出X90钢级Φ1 219 mm×16.3 mm超高强度螺旋埋弧焊管。按照标准对该产品进行了组批性能检测，结果显示，钢管管体横向屈服强度625~740 MPa，抗拉强度715~835 MPa，焊缝抗拉强度770~825 MPa；焊接接头最大硬度小于270HV10；-10 ℃下管体横向平均冲击功大于340 J，热影响区平均冲击功大于197 J，焊缝平均冲击功大于133 J；0 ℃下管体横向DWTT剪切面积均为100%。结果表明，开发的钢管具有优异的强度、塑性及韧性匹配，焊接性能良好。

Research and Development of X90 Steel Grade Large Diameter SAWH Pipe

In response to the trend of high strength, high pressure pipeline construction development requirements, adopting low C, high Mn, Mo-Cr-Ni-Cu-Nb-Ti alloy design system and controlled rolling and controlled cooling technology, it developed X90 pipeline steel which consists of most granular bainite and less strip bainite ferrite. Through research on low stress forming technology, welding technology and so on, the ultra-high strength X90 steel grade 1219 mm×16.3 mm SAWH pipe was successfully developed. The group batch performance test was conducted in accordance with relevant technical standard, and the test results showed that the transverse yield strength of pipe body is 625~740 MPa, the tensile strength is 715~835 MPa, the tensile strength of weld seam is 770~825 MPa; the hardness of welded joint is less than 270HV10; the average transverse impact energy of pipe body is higher than 340 J under-10℃, the average impact energy of HAZ is higher than 197 J, the average impact of weld seam is higher than 133 J; and the transverse DWTT shear area of pipe body is 100% under 0 ℃. It is concluded that the developed steel pipe has excellent strength, plasticity, toughness and toughness matching, the weldability is good.