预应变量和时效对X80HD2钢厚壁大变形直缝焊管低温冲击性能的影响

Effects of pre-strain and aging on low temperature impact properties of X80HD2 steel thick wall high deformation longitudinal welded pipe

通过拉伸、冲击试验研究了预应变量和时效温度对厚壁X80HD2大变形直缝埋弧焊管低温冲击韧性的影响,测定了不同应变时效条件下的夏比冲击吸收能量和剪切断面率,用扫描电镜观察了不同温度下冲击断口形貌。结果表明,随着预应变量的提高和时效温度的增加,夏比冲击吸收能量和剪切断面率逐渐减小,增加预应变量对低温冲击韧性的恶化效果高于提高时效温度;此外,增加预应变量将加大断口分离的倾向性,提高时效温度则对断口分离倾向性的影响不显著;增加预应变量和提高时效温度均使冲击断口发生准解理断裂的倾向增加。

Effects of pre-strain and aging temperature on low temperature impact toughness of X 80 HD2 high deformation longitudinal submerged arc welded pipe were investigated by using tensile test and charpy impact test .The Charpy impact absorbed energy and percent of shear fracture after different strain aging process were determined .The fracture morpholoties at different temperature were observed by using SEM.The results show that the charpy impact absorbed energy and percent of shear fracture decrease with the increase of pre -strain and aging temperatrue;the deterioration of low temperature impact toughness with the increase of pre-strain is greater than that of aging temperature increasing.Besides, the fracture seperation tendency will raise with the increase of pre-strain and there is no notable relationship between the tendency of fracture seperation and aging temperature .Finally, the quasi-cleavage trend will be enhanced with the increse of pre-strain and aging temperatrue .