不同厚度堆焊层表面残余应力分析

AbstractThe paper based on the welding low carbon steel Q235 steel plate as the research object,and blind hole method using simulated stress and strain measuring two ways to explore thedifferent depth influence on welding residual stress in the repairing layer.Through thesimulation results and experimental results analysis,has been clear about the different thicknessof melting layer in the residual stress distribution rule.In this paper,through the establishment of the depth of 4 kinds of weld bead,the finiteelement software MSC.Marc to carry on the numerical simulation,using the Marc unit and heat-structure coupling function analysis for simulation of welding process.Is given along the weldresidual stress distribution in different directions of three dimensional curve,compare thedifferent depth of surfacing welding layer in the longitudinal stress and strain of different,different depth of the repair layer on the surface of welding residual stress distribution rule.Themain conclusions of surfacing layer thickness is 2 mm,3 mm,4 mm,5 mm weld longitudinaltensile stress is 191 MPa and 305 MPa,respectively 423 MPa and 628 MPa.That with theincrease of surfacing layer thickness the surface residual stress increases.In order to verify the simulation results accuracy,on the base of Q235 low carbon steelplate milling groove of different depth,manual electric arc welding,using D112 electrode fordifferent thickness of bead welding layer,using blind hole method of measuring the residualstress value of surfacing welding layer.The experimental results for the surfacing layer thicknessis 2 mm,3 mm,4 mm,5 mm weld longitudinal tensile stress is 267 MPa and 353 MPa,respectively 577 MPa and 773 MPa.That with the increase of surfacing layer thickness thesurface residual stress increases.Comparing the finite element simulation analysis and blind hole method to themeasured results,there is a certain gap,this is due to the finite element simulation,mechanical surfacing materials caused by parameter settings.However,both are in goodagreement in the trend,thus the finite element simulation can improve the materialparameters precision condition,can guide the welding residual stress research.Key Words:Surfacing layer;finite element simulation;Welding residual stress;Blind-hole method;Q235II