Experiment And Numerical Simulation Of Water-jet Cavitation Peening Processing In45Steel

Water cavitation peening technology utilizes the lots of clusters of thecavitation bubbles caused by the submerge cavitation jet. These cavitationbubbles clusters could produce as high as several GPa shock wave whichinduced the residual stress layer to strengthen the surface of thecomponent and improve the fatigue life of the component. As the modernindustry developing fast, the loading capacity of the steel is requiredhigher and higher and lots of components and parts would be affected bythe alternating load to produce fatigue cracks which could lead to thefailure of the components in the final. Therefore the water cavitationpeening technology could be applied to produce the residual stress layeron the surface of the steel so as to improve the fatigue life of the steel.The recent research have discovered that the WCP technology has thesame ability of forming compressive residual stress layer on the metalsurface as the traditional peening technology,improving the fatigue life ofthe specimen.The basic theory of inducing cavitation behavior andresidual stress field is so weak that it prevents the improvement anddevelopment of WCP technology. According to the status, this paper willstudy the strengthening process of WCP technology on45steel and thefinal distribution of residual stress fields.The numerical simulation was widely applied for the reason of its lowcost and high efficiency. According to45steel on cavitating water shotpeening tests, a bilinear isotropic model in nonlinear inelastic model wascreated by ANSYS/LS-DYNA finite element analysis software, theinteraction between shock wave pressure and material of dynamics of thecavitating jets processing was simulated, and the distribution rule ofcompress residual stress forming in the surface layer the constitutiverelation, meshing, load magnitude, load history and other key issues isdiscussed. The shock wave pressure under different peak load and themethod of continuous wave loading was adopted to predict thedistribution of residual stress. The final distribution of residual stress fieldof45steel under different conditions of peak load and wave load wasreceived, when the single blast acts on material surface, the size and deep of the residual stress increases with the increase of shock wave peak,when the shock wave peak is constant, the size and layer depth of residualstress increases with the increase of the number of shock waves. A smallresidual stress measurement device (PSPC/MICRO) which is based onthe method of X-ray diffraction is used to test the residual stress inducedby WCP. Compared with the simulation results, the simulation results ofshock load P=1.2GPa,1.4GPa are in agreement with shot peening time30min of cavitation water shot peening experiment.