调质工艺对V微合金油井管用钢力学性能的影响

为应对复杂苛刻的工作环境，开发出可以达到Q125钢级标准的高抗拉、抗压和抗挤毁性能的油井管用钢，研究了调质工艺对V微合金化试样微观组织和力学性能的影响.结果表明:经调质处理后的实验钢的微观组织主要是回火马氏体和微量贝氏体，碳化物大量析出，使材料具有良好的综合力学性能.较低的回火温度和较长的回火时间可增加碳化物的析出量，从而增强沉淀强化作用.在610℃下回火70min的综合力学性能最佳，屈服强度、抗拉强度及伸长率分别可达954MPa，989MPa及13.5%. 0℃冲击功横向为25J，轧向为46J，满足Q125钢级油井管标准要求.

Effect of Quenching and Tempering Treatment on Mechanical Properties of V-microalloyed Steel for Oil Well Pipe

In order to cope with in complex and harsh work environments， a new-typed steel for oil well pipe has been developed， whose tensile strength， compressive strength and collapse resistant can reach steel grade of Q125.The effect of quenching and tempering(Q&T)treatment on microstructure and mechanical properties of the V-microalloyed steel was studied. The results show that the microstructure of the experimental steel after Q&T treatment contains tempered martensite， a little bainite and a large number of carbide precipitations， so that the steel has good comprehensive mechanical properties. Lower tempering temperature and longer tempering time can increase the amount of of carbide precipitations， leading to a higher precipitation hardening. Mechanical properties of the steel after tempering at 610℃ for 70min has the best performance， where the yield strength， tensile strength and elongation can reach 954MPa， 989MPa and 13.5%， respectively. The impact energy at 0℃ is 25J in transverse direction and 46J in rolling direction， which meets the requirements of steel grade of Q125 for oil well pipe.