中文摘要：

利用MTS万能试验机研究了X70管线钢在不同应力加载速率和不同加载过程下的室温蠕变现象，以及室温蠕变对流变应力的影响。结果表明，X70管线钢有明显的室温蠕变现象存在，应力加载速率和加载过程对室温蠕变变形量有明显的影响，而且室温蠕变显著提高了材料的流变应力。并根据位错理论对实验结果进行了分析解释。

英文摘要：

The phenomenon of room temperature creep （RTC） deformation and its effect on subsequent flow stress under various loading stress rate （Lsr） and loading process in a X70 pipeline steel were studied. The experiments were performed on a MTS 810 testing machine by using standard round tension specimens. According to the results, significant time-dependent deformation under constant load was observed in this steel at room temperature, and the deformation was strongly dependent on loading stress rate and loading process. It was also found that the occurrence of room temperature creep obviously enhanced the subsequent flow stresses. Model based on dislocation theory was applied to explain the mechanism responsible for the behavior.