一、前言钢板弹簧是汽车上较重要的总成之一,在非对称的交变弯曲负荷下工作。簧片是组成整个板簧总成的单元,它的疲劳强度直接影响到总成的质量。目前,许多生产单位都采用了喷丸或预应力喷丸的办法来提高板簧的寿命。一般认为,喷丸之所以能提高受弯零件的疲劳寿命,主要是由于喷丸过程在零件表面产生了一个残余压应力层,当零件受到交变负荷作用的时候,残余应力峰值起到一个平均应力的作用。所以,残余压缩应力能提高零件的抗拉疲劳强度,而残余拉伸应力则相反。从这观点出发,当然希望承拉(弯)零件表面的残余压应力越大越好。采用屈服点较高的材料制作零件,喷丸后所得的残余压应力也较大,在无预应力的情况下喷丸所得的残余压应力峰值约为材料屈服强度的一半,改变喷丸时簧片受喷面的应力状态,可获得不同的残余应 I. INTRODUCTION Leaf spring is one of the more important assemblies in a car, working under an asymmetrical alternating bending load. Reed is composed of the entire leaf spring assembly unit, its fatigue strength directly affects the quality of the assembly. At present, many production units have used shot peening or pre-stressing shot peening to increase the life of the leaf springs. Generally believed that the reason that shot peening can improve the fatigue life of the bent parts is mainly due to the shot peening process in the surface of the part has a residual compressive stress layer, when the parts are subjected to alternating load, the residual stress peaks play an average The role of stress. Therefore, the residual compressive stress can improve the tensile fatigue strength of the part, while the residual tensile stress is the opposite. From this point of view, it is certainly desirable that the greater the residual compressive stress on the surface of the bearing (bent) part, the better. Using the material with higher yield point to make parts, the residual compressive stress obtained after shot peening is also larger, the residual compressive stress peak obtained by shot peening in the absence of prestressing is about half that of the material yield strength, Sheet by the spray surface stress state, can get different residual should