论文部分内容阅读
通过对应变时效去及去应力退火前后未扩径钢管拉伸、冲击、硬度、导向弯曲试验的对比,分析了应变时效及去应力退火对未扩径钢管力学性能的影响。结果表明,对未扩径的钢管先经过250℃应变时效,再经过600℃去应力退火后,未扩径钢管的力学性能得到改善,表现为母材的屈服强度、抗拉强度及伸长率升高,屈强比略有减小;焊缝的抗拉强度和硬度得到提高。母材、焊缝及热影响区的冲击性能略有下降,下降幅度对其冲击性能不会造成较大影响。经应变时效及去应力退火后焊缝弯曲试样未出现裂纹。合理的应变时效及去应力退火,可提高钢管的综合力学性能,且可以充分消除焊接残余应力。
The effects of strain aging and stress relief annealing on the mechanical properties of un-expanded steel tubes were analyzed by comparing the tensile, impact, hardness and guided bending tests of un-expanded steel tubes before and after strain-aging and stress-relief annealing. The results show that the mechanical properties of unamplified steel pipe are improved after strain aging at 250 ℃ and then stress-relief annealed at 600 ℃ for the unexpanded steel pipe. The results show that the yield strength, tensile strength and elongation Increased slightly, yield ratio slightly reduced; tensile strength and hardness of the weld is improved. The impact properties of base metal, weld and heat affected zone slightly decreased, and the drop amplitude had no significant impact on the impact performance. After the strain aging and stress relief annealing specimens after bending cracks did not appear. Reasonable strain aging and stress relief annealing, can improve the comprehensive mechanical properties of steel, and can fully eliminate the welding residual stress.