大口径大壁厚38.5 mmX80管线钢开发与应用

Development and Application of 38.5mmX80 Large Diameter Large Wall Thickness Pipeline Steel

采用超低碳和微合金化的成分设计,配合适当的控轧控冷工艺,成功开发出大口径大壁厚38.5mm×4322 mmX80M管线钢板。钢板组织以针状铁素体+粒状贝氏体为主,具有高强度、良好的低温韧性和止裂性能。钢板经JCOE工艺制成1422 mm×38.5 mm规格钢管,钢管屈服强度579~606 MPa,抗拉强度648~656 MPa,延伸率≥26%,屈强比≤0.92,10℃冲击功≥330 J,-22℃双面减薄DWTT≥95%,横向冲击FATT50CVN低于60℃,横向双面减薄落锤FATT85DWTT为-45℃。各项性能符合Q/SY XG 0120.4-2019《西气东输四线天然气管道工程用X80级直缝埋弧焊管技术条件》和D1422×38.5 mm管材单炉试制程序及要求。

In this paper,the 38.5 mm×4322 mm X80 large diameter large wall thickness pipeline steel was successfully developed by adopting ultra low carbon micro alloy chemical design and controlled rolling and cooling process.With acicular ferrite+granular bainite as its major micro-structure,the steel plate obtains high strength,good low temperature toughness and solid anti-crack performance.After JCOE process,the plates were bended into1422 mm×38.5 mm pipes.Through tests we found that for pipes the yield strength ranges within 579~606 MPa,tensile strength is within 648~656 MPa,elongation is≥26%,Y/T ratio is≤0.92,10℃impact is≥330 J,-22℃double-sided thinning DWTT is≥95%,transverse impact FATT50 CVN is lower than-60℃,and the transverse drop weight of double-sided thinned FATT85 DWTT is-45℃.Thus all the above properties conform with Q/SY XG 0120.4-2019 X80 LSAW Pipe for Natural Gas Pipeline Project:West to East Gas Pipeline 4-Technical Delivery Conditions and Individual Furnace Trial Procedure and Requirements for D1422×38.5 mm Steel Pipe.