Factors generating microscopic residual shear stress τ
ZXW in uni-directionally machined layers produced by cutting and grinding were studied experimentally. In the affected layers, residual strain distributions depend on machining direction and the strains are generated by τ
ZXW. In affected layers, generally, macroscopic residual stresses are thought to consist of three elements resulting from thermal, burnishing or rubbing and mechanical cutting action of a cutting tooth and abrasive grains during machining process. Relations between the three elements and τ
ZXW were also investigated experimentally and the following can be summarized.τ
ZXWis extinguished in process ofrecovery dueto heating at low temperature in furnace. τ
ZXW produced by cutting and grinding increases as carbon content of steel increases, but has a tendency to be saturated in carbon segregated regions. These results show that τ
ZXW is a phase stress generated by elastic recovery force of cementite acting upon slip plane of ferrite grains. On the other hand, the travelling heat source at high temperature decreasesτ
ZXW and generates microscopic residualstress.τ
ZXW generated in pearlite structure is greaterthan one in spheroidal cementite structure. The factors of generating τ
ZXW are mechanical cutting and burnishing action, microstructures of steel and machining conditions.
抄録全体を表示