Q345钢生产双相钢无缝钢管的工艺试验及成型性能评价

通过对Q345无缝钢管进行中频感应加热及环形喷水冷却,得到了铁素体+马氏体的双相钢无缝钢管。采用单向拉伸试验测试钢管的力学性能,结合钢管在扫描电镜和透射电镜下的微观组织形貌,分析了临界区不同退火温度对双相钢无缝钢管的组织及性能的影响。采用管端扩口试验方法,对试验钢管的成型性能进行评价。结果表明:Q345无缝钢管通过中频感应加热至临界区退火后,可获得高强度、高成型性能的双相钢无缝钢管,其中750℃退火后,试验钢管的各相分布较为均匀,应力应变曲线呈现连续屈服状态,强塑积可以达到16 510 MPa·%。

Technological Tests on Dual Phase Seamless Steel Pipe Made from Q345 Steel and Evaluation of its Forming Performance

By applying intermediate frequency induction heating and spray ring cooling on a Q345 seamless steel pipe, a dual phase seamless steel pipe containing ferrite and martensite is made. Analyzed the influence of different intercritical annealing temperatures on the structure and properties of the dual phase seamless steel pipe. Also evaluated is the forming performance of the testing pipe by the pipe end expanding test. The results of the tests indicate that when a Q345 seamless steel pipe is heated to intercritical temperature by intermediate frequency induction heating and then treated by annealing, a dual phase seamless steel pipe with high strength and high forming performance will be made. For example, after being annealed at 750 ~C, the testing pipe will have a relatively homogeneous phase distribution, a stress-strain curve showing continuous yielding and a product of strength and elongation reaching 16 510 MPa· %.