【摘要】 低C高Nb高Mn的合金设计已广泛应用于X80管线钢,X80管线钢钢管的直缝焊接以及螺旋缝焊接性能对该合金体系的应用极其重要。热模拟研究结果表明,该合金体系X80管线钢的最佳热输入量应低于30 kJ/cm。相比于普通Nb含量管线钢,高Nb含量设计管线钢的粗晶区(CGHAZ)晶粒尺寸更细;临界粗晶区(ICCGHAZ)并没有粗大的析出物,Nb(CN)的尺寸≤30 nm。直缝焊及螺旋焊X80钢管的大量工业生产数据表明,高Nb X80管线钢热影响区的力学性能,特别是韧性能达到较高的水平,完全满足西气东输二线的技术指标,该合金体系的应用为西气东输二线的成功建成提供了有力保障。更多还原

【Abstract】 Low carbon high Nb and high Mn microalloying design has been applied to X80 pipeline steel,the longitudinal and submerged arc weling performance of X80 line pipe are of prime importance to application of the said alloy system.The results of thermal simulation study showed that the optimum heat input energy for alloy system X80 steel should be lower than 30 kJ/cm.The grain size of CGHAZ of high Nb pipeline steel is smaller than that of common Nb steel;the coarse precipitates do not appear in ICCGHAZ,and the size of Nb(CN) is not more than 30nm.A large number of production data indicated that the mechanical properties of HAZ in high Nb X80 pipeline steel,especially the toughness,can reach high level,which can fully meet the requirements of the Second West-east Gas Pipeline Project.The application of this alloy system provided the Second West-east Gas Pipeline Project with powerful safeguard.更多还原