基于压痕理论的超高压射流喷射强化304钢表面特性研究  

Surface Characteristic of 304 Steel after Ultra-high Pressure Jet Peening Based on Indentation Theory

作　　者：吴仪政 胡锦程 傅亦饶 文晓婷 张天一 王晓川[1,2] WU Yi-zheng;HU Jin-cheng;FU Yi-rao;WEN Xiao-ting;ZHANG Tian-yi;WANG Xiao-chuan(School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China;Hubei Key Laboratory of Waterjet Theory and New Technology,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学动力与机械学院,武汉430072 [2]武汉大学水射流理论与新技术湖北省重点实验室,武汉430072

出　　处：《表面技术》2023年第7期406-416,共11页Surface Technology

基　　金：国家自然科学基金(52074194)。

摘　　要：目的高压纯水射流喷射冲击金属表面可以提高材料的力学性能,延长其使用寿命,研究射流喷射过程中金属表面特性有助于掌握关键影响参数,为工业应用提供支撑。方法基于压痕断裂理论推导纯水射流喷射强化金属表面压痕方程式,采用数值模拟进行验证,并使用扫描电子显微镜、三维轮廓仪、显微硬度计及μsoft analysis软件对射流冲击强化后的304钢进行试验分析,采用单因素法及正交试验法考察超高压水射流压强、靶距和横移速度3个因素对射流冲击强化304钢微观特性及表面质量的影响规律。结果在水射流冲击强化304钢表面的过程中,压痕深度与射流压强及靶距直接相关,射流冲击可以有效改善金属表层微结构及应力分布,其强化层与剥落层的分界不明显,材料表面的微观形貌在射流压强改变时变化最大。结论高压纯水射流对304钢的表面强化效果显著,但过高的射流能量会对材料表面造成严重的剔除效果。3个因素对表面粗糙度影响的主次顺序为:射流压强、靶距、横移速度,对表面硬度影响的主次顺序为:射流压强、靶距、横移速度。Using high pressure water jet to impact the metal surface can make the mechanical properties of the material better and increase its service time.The analysis on properties of the metal surface during the jet peening can assist to grasp the key influencing parameters,so as to provide industrial support.This paper derived the indentation equation of metal surface strengthened by pure water jet based on indentation fracture theory and verified it by numerical simulation,then studied the influence that jet pressure,standoff distance and transverse speed have on the surface micro morphology,surface roughness and surface hardness of 304 steel which was impacted by high pressure pure water jet.The main experimental instrument was a water jet scalpel,the moving speeds of its x-axis,y-axis and z-axis were 6,6,and 1 m/min respectively,the maximum moving speed was 6 m/min,the control accuracy was±0.01 mm,and the diameter of the nozzle was 1.2 mm.In this work,a three-dimensional profiler and a scanning electron microscope were used to observe the surface micro characteristic of the material,the surface roughness of the material was measured by a three-dimensional surface topography measurement system andμsoft analysis software,and a micro hardness tester was used to measure the surface hardness.The three factors of jet pressure,standoff distance,and traverse speed were used as experimental variables to conduct the experiment that the 304 steel was strengthened by high pressure pure water jet.In the experiment,the jet pressure was 180,240 and 300 MPa respectively,the standoff distance was 10,15 and 20 mm respectively,the transverse speed was 400,600 and 800 mm/min respectively.First,a single factor experiment was conducted to explore the influence law of the three factors,then an orthogonal experiment was used to find out the extent of this influence.It was discovered that the indentation depth was directly related to jet pressure and standoff distance in the water jet treatment.Jet treatment can effectively improve the mi

关 键 词：纯水射流 304钢 金属表面强化 压痕理论 微观形貌 表面粗糙度 

分 类 号：TG668[金属学及工艺—金属切削加工及机床]