304不锈钢水射流强化工艺的多目标优化设计

Multi-objective Optimal Design of Enhancing Technology for 304 Stainless Steel by Water Jet Peening

目的得到水射流强化技术工艺参数(水压、靶距、速度、进给量)对304不锈钢表层性能指标(残余应力、硬度和粗糙度)的影响程度。方法采用X射线残余应力分析仪、三维形貌仪和显微硬度计,分别测试304不锈钢水射流后表面的残余应力、粗糙度和显微硬度值。利用显著性方法分析正交试验结果,并通过多目标优化设计对不同水射流工艺参数下的强化效果进行综合性研究。结果影响304不锈钢表层性能指标的水射流工艺参数由强到弱的顺序依次为:进给量、水压、速度和靶距。经过多目标优化设计,得到了304不锈钢水射流强化工艺参数的最佳组合:水压300 MPa,靶距15 mm,速度400 mm/min,进给量0.125 mm。结论水射流工艺参数的制定主要考虑进给量和水压两者的影响,而速度和靶距对表层性能指标的影响较小。

The work aims to explore effects of process parameters（water pressure, target distance, speed and feed） of water jet peening enhancing technology on performance indicators（residual stress, hardness, roughness） of 304 stainless steel surface. The residual stress, roughness and microhardness of the surface receiving water jet peening were tested with XRD stress analyzer, optical profilometer and microhardness tester, respectively. Orthogonal test results were analyzed in significance approach, and enhancing effects provided with different water jet peening process parameters were comprehensively studied based upon multi-objective optimal design. It was found that feed rate had the greatest effect on the mechanical properties, then water pressure and speed, and finally target distance. Based upon the multi-objective optimal design, the best parameter combination for 304 stainless steel enhanced by water jet peening was obtained： water pressure as 300 MPa, target distance as 15 mm, speed as 400 mm/min and feed rate as 0.125 mm. Effects of feed rate and water pressure are mainly considered to determine water jet peening process parameters while those of speed and target distance can be neglected.