大变形管线钢管应变时效硬化研究

高强度管线钢管（X80级及以上钢级）加热并保温一段时间后，钢管力学性能将发生变化（应变时效），通常屈服强度、屈强比升高，屈服点延伸，应力－应变曲线形状改变等，这些性能变化对于钢管应变能力会产生不利的影响。通过对日本JFE公司提供的X80级、Φ1219mm×22mm抗大应变钢管实物的试验检测、研究，分析了对性能有影响的加热温度和保温时间以及应变时效对材料性能的影响规律，为西气东输二线管道工程应用此类钢管提供了依据。

Study on Strain Aging Hardening of Large Distortion Steel

The mechanical properties (strain aging) of the high strength linepipe steel (grade X80 and above) is different between before and after heating at a certain temperature, and temperature holding time.Unexceptional Yield strength and Y/T ration is increased,yield elongation occurred,and the shape of stress strain curve changes after heating.Such variations of properties will make bad effect to deformability of steel pipes.In this paper, heating temperature and holding time which have effected on properties are determined by the test and study of the steel pipes with the large deformation X80 Φ1219×22mm (pipes were supplied by JFE),and the influence rules of the strain-aging to the material properties is also obtained,which provides reference for such application in the second West-East Gas pipeline.