超声振动滚挤压对金属表面微观组织的影响

Investigations on Effects of Ultrasonic Rolling Process on Surface Microstructure of Steel

超声振动滚挤压技术为新型高能表面强化技术,对提升表面完整性和改善零件抗疲劳性能有显著效果。选用45钢金属材料进行了超声振动滚挤压对表面微观组织影响的试验研究,并分析了超声振动滚挤压对改善表面微观组织的作用机理。结果表明:超声振动滚挤压能够使零件表面微观组织出现明显的纤维化效果,且纤维化程度与超声振幅、挤压速度有关;超声振幅越大,零件表面的纤维组织越细,当振幅A=6μm时,小纤维厚度达1.25μm;挤压速度越小越有利于纤维组织的产生,产生的纤维宽度也越细,当挤压速度大于345mm/s时,不再产生纤维组织。表面组织的纤维化有效提升了零件的抗疲劳性能。

Ultrasonic rolling process,as a novel high energy technology,can effectively improve surface roughness,and greatly improve fatigue performance of part. In the present part,experimental work are carried out on the behavior of microstructure on the surface of 45 steel by using of ultrasonic rolling process,and effects of ultrasonic vibrations on behavior of microstructure are analyzed.The results show that a mass of fibrosis grains can be generated by using of ultrasonic rolling process,while the ultrasonic vibration plays a key role on the generation of fibrosis grains.Smaller fibrosis grains can be achieved by using of a larger vibration amplitude,while the size of fibrosis grains is 1.25μm when a 6μm vibration amplitude is adopted. Smaller fibrosis grains can also be achieved by using of lower rolling speed,while no fibrosis grains can be achieved when the speed is larger than 345mm/s.It can be inferred that the generation of fibrosis grains greatly contributes to the improvement of fatigue performance.