Modelling of Tool Wear and Residual Stress during Machining of AISI H13 Tool Steel

摘要

Residual stresses can enhance or impair the ability of a component to withstand loading conditions in service(fatigue,creep,stress corrosion cracking,etc.),depending on their nature;compressive or tensile,respectively.This poses enormous problems in structural assembly as this affects the structural integrity of the whole part.In addition,tool wear issues are of critical importance in manufacturing since these affect component quality,tool life and machining cost.Therefore,prediction and control of both tool wear and the residual stresses in machining are absolutely necessary.In this work,a two-dimensional Finite Element model using an implicit Lagrangian formulation with an automatic remeshing was applied to simulate the orthogonal cutting process of AISI HI3 tool steel.To validate such model the predicted and experimentally measured chip geometry,cutting forces,temperatures,tool wear and residual stresses on the machined affected layers were compared.The proposed FE model allowed us to investigate the influence of tool geometry,cutting regime parameters and tool wear on residual stress distribution in the machined surface and subsurface of AISI HI 3 tool steel.The obtained results permit to conclude that in order to reduce the magnitude of surface residual stresses,the cutting speed should be increased,the uncut chip thickness(or feed)should be reduced and machining with honed tools having large cutting edge radii produce better results than chamfered tools.Moreover,increasing tool wear increases the magnitude of surface residual stresses.