火次变形量及退火温度对Gr.9合金管材组织与性能影响

Influence of Deformation Between Heating on Microstructure and Mechanical Properties of Gr.9 Tubes

研究了火次变形量和退火温度对Gr.9合金管材显微组织和力学性能的影响,探讨了高强Gr.9合金管材的制备方法。结果表明:采用取消成品轧制道次前退火工序以增加火次变形量的方法及优化去应力退火温度可制备出满足标准要求的高强Gr.9合金管材。增加火次变形量使管材的强度提高,但塑性有所下降;同时使管材流线组织更为明显,晶粒破碎程度更为充分。经过470℃×90 min去应力退火后,火次变形量较大的管材强塑性可达到较优的匹配,从而满足Rm≥862 MPa,Rp0.2≥724 MPa,A50≥12%。

The influence of deformation between heating numbers and annealing temperature on the microstructure and mechanical property of Gr. 9 alloy tubes were studied, and the prepared method for high - strength Gr. 9 alloy tubes was also discussed. The results show that high strength Gr. 9 alloy tubes can be produced by cancelling process of anneal, increasing deformation between heating and optimizing relief annealing temperature. Increasing deformation between heating numbers can obviously improve the strength of tubes, but decrease plasticity. Meanwhile, it makes the fiber flow lines in microstructure of tubes much more conspicuous, and the grains thinner. By the process at 470 ℃ for 90 min stress relief annealing, the strength and plasticity of tubes can meet Rm ≥862 MPa, Rp0.2 ≥ 724 MPa, A50≥ 12%.