高强油井管用钢高温性能研究

针对550 MPa级高强稠油热采井套管断裂失效的问题，对套管用钢的高温力学性能和蠕变性能进行了研究。在不同温度下对试验钢板进行了高温拉伸和蠕变试验，利用SEM和TEM观察了试样组织及断口形貌。结果表明：试验钢板在350℃时，屈服强度和抗拉强度下降约8%,蠕变速率1.46×10^-6 h^-1;在400℃时，屈服强度和抗拉强度下降约18%,蠕变速率5.34×10^-6 h^-1;随着拉伸试验温度的升高，由于碳化物和析出相的影响，试样断口的孔洞尺寸明显增大，造成性能下降；Cr、Mo的强碳化物析出物对位错滑移的阻碍作用提高了试验钢的抗蠕变性能。

Research on high-temperature performance of high-strength oil pipeline steel

Aiming at the fracture failure of 550 MPa high strength heavy oil hot production casing, the high temperature mechanical properties and creep properties of casing steel were studied. The high-temperature tensile and creep tests of the tested plate were carried out at different temperatures, and the sample structure and fracture morphology were observed by SEM and TEM. The results showed that the yield strength and tensile strength of the tested plate decreased by about 8% at 350 ℃, and the creep rate was 1.46×10^-6 h^-1.At 400 ℃, the yield strength and tensile strength decreased by about 18%, and the creep rate was 5.34×10^-6 h^-1. With the increase of tensile test temperature, due to the influence of carbide and precipitated phase, the size of the hole in the fracture of the specimen increases significantly, resulting in the deterioration of performance. The strong carbide precipitates of Cr and Mo hinder the dislocation slip to improve the creep resistance of the tested steel.