前混合水射流喷丸单丸粒冲击特性研究

Study on Impact Characteristics of Single Shot in Suspension Water Jet Peening

单丸粒冲击特性是研究混合射流表面喷丸强度和覆盖率的基础指标,丸粒特性与靶材特性均会对冲击后的弹坑形态产生影响。以不同热处理后的18CrNiMo7-6低碳合金钢为靶材,研究了不同丸粒冲击条件下的弹坑特性。从弹坑形成机理出发,建立了单丸粒冲击弹坑尺寸模型,并通过试验研究,修正了高硬度靶材弹坑的误差,使弹坑深度预测误差降低到30%以下。在此基础上,研究了弹坑相关特征参数(深径比、坑深坑直径占比、脊高)的规律。结果表明,丸粒硬度和靶材硬度对深径比以及坑深直径占比影响最为显著,而弹坑周边的脊状结构只存在于低硬度靶材中。各参数对脊高的影响由大到小分别为丸粒直径、丸粒硬度和丸粒速度。

The impact characteristics of a single shot are the fundamental indicators for studying the strength and coverage of mixed jet surface shot peening.The characteristics of the shot and the target material both have an impact on the crater characteristics after impact.This article uses 18CrNiMo7–6 low-carbon alloy steel after different heat treatments as the target material to study the crater characteristics under different shot impact conditions.Starting from the mechanism of crater formation,a single shot impact crater size model was established,and through experimental research,the error of high hardness target crater was corrected,reducing the prediction error of crater depth to less than 30%.On this basis,the laws of crater related characteristic parameters(depth to diameter ratio,proportion of crater diameter and crater depth,and ridge height)were studied.It was found that the hardness of shot particles and target materials had the most significant impact on the depth to diameter ratio and proportion of crater diameter and crater depth,while the ridge like structure around the crater only existed in low hardness target materials.The influence order of each parameter on ridge height is shot diameter,shot hardness,and shot velocity,respectively.