【摘要】 研究某厂试生产的X80输油气管线钢的显微组织结构和常规力学性能。该钢板以针状铁素体组织为主 ,晶粒 12级。采用四点弯曲方法 ,模拟制管工艺进行钢板的包申格效应研究。在屈服变形阶段 ,随预变形量的增加 ,由包申格效应导致的屈服强度损失单调的增加 ,此现象与屈服过程中 ,钉扎位错的脱钉 ,形成大量有方向性的可动位错有关。按API标准 ,从试制的 610mm× 7.9mm螺旋钢管取样进行测试 ,结果发现钢管由包申格效应导致的屈服强度损失 ,除卷板头部和尾部略高外 ,沿板长平均在 5 5MPa至 75MPa之间。包申格效应的影响不可忽视更多还原

【Abstract】 The microstructure and the routine-mechanical properties of X80 grade pipeline steel tentatively produced are presented by a steel corporation. It is found that the major part of phase is consisted of needle-like ferrite with grade 12 grain. The Bauschinger effect investigation was conducted by four point bending to simulate the tube-making process. In the period of yield strain,the loss of yield strength due to Bauschinger effect is monotonicly increased by the increase of pre-strain. Such type of phenomenon could be closely attributed to the formation of huge amount of directionally mobil dislocation after unpinning during yield process. Following API specification,the specimens for tensite test were taken from 610?mm×7.9?mm SSAW tube,the results indicate that the yield strength loss by Bauschinger effect is within the range of 55?MPa～75?MPa along the longitudinal direction of plate except for the head and tail portion,having little higher value. Bauschinger effect can not be neglected both in designing and manufacturing.更多还原