目的 对高压纯水射流强化后的45钢表面进行研究，分析工艺参数对强化表面残余压应力与表面粗糙度的影响。方法 采用正交试验法研究射流压强、靶距、横移速度、进给量和循环次数对强化质量的影响。利用Minitab软件对试验结果进行分析，研究其影响规律，并探究最佳工艺组合。结果 工艺参数对纯水射流强化表面残余压应力影响程度的主次顺序依次为：循环次数>进给量>压强>横移速度>靶距；工艺参数对纯水射流强化表面粗糙度影响程度的主次顺序依次为：压强>循环次数>进给量>横移速度>靶距；工艺参数对纯水射流强化表面质量影响程度的主次顺序依次为：压强>靶距>进给量>循环次数>横移速度。综合强化表面残余压应力与表面粗糙度，得到最优工艺参数：射流压强200 MPa、靶距10 mm、进给量0.5 mm、循环次数2次、横移速度100 mm/min。结论 高压纯水射流对45钢的表面强化效果显著，所得强化表面残余压应力提升明显，但表面粗糙度提升不明显，表面粗糙度值低于1.1 μm。

The work aims to study on the surface of 45 steel strengthened by high pressure pure water jet, and analyze the influence of technological parameters on the strengthening surface residual compressive stress and surface roughness. The or-thogonal experimental method was used to study the influence of jet pressure, standoff distance, transverse speed, feed rate and cycle times on the surface quality. Minitab software was used to analyze the test results, study the influence law, and explore the best process combination. From the research, the order of influence of process parameters on residual compressive stress is as follows: times > feed > pressure > traverse speed > standoff distance. The order of influence on surface roughness is pressure > times > feed > traverse speed > standoff distance. As to the surface quality, the order is pressure > standoff distance > feed > times > traverse speed. The optimal process parameters are obtained: jet pressure 200 MPa, standoff distance 10 mm, feed rate 0.5 mm, cycle times 2 and transversal speed 100 mm/min. In a few words, the effect of high pressure pure water jet on the surface hardening of 45 steel is remarkable. The surface residual compressive stress is improved obviously while the surface roughness does not increase obviously, and the surface roughness is lower than 1.1 μm.