FAN J K, LIU S, ZHAO W.Study on mechanism of thin rubber layer in improving shot peening quality[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(4):103-110.

doi:10.16186/j.cnki.1673-9787.2022040037

Received:2022/04/14

Revised:2022/09/05

Published:2024/07/05

Study on mechanism of thin rubber layer in improving shot peening quality

FAN Junkai, LIU Shuai, ZHAO Wu

School of Mechanical and Power Engineering，Henan Polytechnic University，Jiaozuo 45400，Henan，China

Abstract: Objectives To reduce the surface roughness of metal caused by shot peening，  Methods a novel approach was proposed to apply a thin rubber layer on the metal surface.This process aimed to homogenize the impact pressure of particles through the deformation of the rubber layer，hereby mitigating the increase in roughness resulting from particle impacts.The feasibility and underlying mechanism of this new process were investigated.The simulation models of traditional shot peening，adhesive thin rubber shot peeing，and free laid thin rubber shot peeing were established by the finite element software Abaqus.The particle was modeled as a spherical rigid body with a radius of 0.5 mm and an initial velocity of 50 m/s.The workpiece material was Q235，and the Johnson-Cook constitutive model was adopted.For the thin layer rubber，the two-parameter Mooney-Rivlin constitutive model was employed.The friction coefficient between different components in the simulation model was set to 0.2.All the models were solved by the explicit method.  Results The residual compressive stress at the impact point of particles on the workpiece surface was 96，343，252 MPa under traditional shot peening，adhesive thin rubber shot peeing，and free laid thin rubber shot peeing respectively.Similarly，the maximum residual compressive stress around the workpiece surface was 391，426，373 MPa respectively.There was a significant increase in the residual compressive stress on the workpiece surface with the thin rubber layer.The impact indentations resulting from shot peening processes was 56.2，26.1，35.4 μm，respectively.The application of a thin rubber layer on the workpiece surface effectively mitigated its roughness.The distribution of residual stress on the workpiece surface exhibited a close correlation with the thickness of the employed rubber layer.Specifically，when utilizing rubber layers with 0.05，0.20 mm in thickness，maximum compressive residual stresses of 329，373 MPa respectively at distances of 256，141 μm beneath the workpiece surface were achieved.  Conclusions The large deformation characteristic of rubber enhanced the impact area of particles and extended the duration of impact，thereby serving as the fundamental reason for the improved shot peening quality achieved by a thin rubber layer.

Key words:shot peening;thin rubber layer;roughness;residual compressive stress;finite element method