Az40m Magnesium Alloy Mig Welded Joint Of The Stress-strain Field Simulation Study

As an important welding technology, MIG welding was widely used inthick plate connected of magnesium alloys. Because of the high concentration ofinstantaneous heat input, there will be considerable stress and deformation inwelding process and postwelding. The welding residual stress and deformationwill seriously affect the using properties of magnesium alloy structural parts.Deep cryogenic treatment as a new kind of heat treatment process has beensuccessfully used in part of the black metal and non-ferrous metal welding jointstrengthen studies, but by the experimental cycle is long, the high cost and theequipment of the influence of the scale,deep cryogenic treatment is not suitablefor the large parts of experiments.So for these reasons, in this paper, for the10mm thick AZ40M magnesiumalloy formulate rational welding process, by using the finite element method tothe temperature field simulation of welding and deep cryogenic treatmentprocess. Based on the results of the simulation,3d real-time dynamic simulationand comparative study of the residual deformation and residual stress.In the simulation analysis, considering the nonlinear change of materialphysical parameters, used hot-structure coupling function of ANSYS software,and by the indirect coupling method, made simulation analysis to thetemperature field and stress strain field of the welding process, post weld anddeep cryogenic treatment process. By mapped meshing, on the weld seam andheat-affected zone thinning, the width of the weld direction from the center linenear the classified methods of uniform transition. Using APDL language torealize "life and death unit" technology and moving double ellipsoid heat sourcemodel.Analyzed the temperature fields of welding and deep cryogenic treatmentprocesses with the finite element model. Translated the model into structuralunit for stress and strain analysis, the calculation results show that: Maximumlateral residual stress in the weld ends, the biggest residual stress in the longitudinal seam center line from30mm place, horizontal and verticalmaximum tensile stress in the weld lines are20mm place, heat affected zone isdanger zone; after deep cryogenic treatment, the residual stress of the area by theinfluence of heat source is increased. The residual stress of metal base, far fromthe weld line, was produced; after deep cryogenic treatment, transverse andlongitudinal residual deformations were reduced.