EFFECT OF THE INDUCED DRILLING STRAIN ON THE WELDING RESIDUAL STRESS MEASUREMENT BY BLIND-HOLE METHOD

Analyses of the results of induced drilling strains measured under different stresses show that the drilling strain is related to the stress state under which the workpiece is measured.The induced drilling strain increases as the tensile stress increases when σ≥70N/mm².The induced drilling strain will not change if the compressive stress varies when|σ|<σ_s/√3,and will decrease rapidly to zero as|σ|approaches σ_s/√3.On the basis of experimental results from A3 and 16Mn steel,a proper procedure to deduct the induced drilling strains has been found,and hence the measuring accuracy of the welding residual stress has.been increased greatly.