Research On Metal Welding Joint Strengthened By Technology Of Electromagnetic Heating

Welding has been playing an important role in national economic construction andsocial development. It has penetrated into all areas of manufacturing and has direct impacton product quality, reliability and service life, as well as the production cost, efficiencyand speed of market reaction. However, because of its limitations, the welding joint is easyto produce all kinds of defects. At present, the elimination of weld defects are mainlyconcentrated on welding equipment and welding process improvement and its like at homeand abroad. For welding defects, research into the problems of how to prevent itsexpansion is not sufficient. Electromagnetic thermal crack strengthening technology as akind of new anti-crack reinforcement method, its application in the field of welding ofweld defects "treatment" is of positive significance. In this paper, numerical simulationand experimental research method of combining the electromagnetic heat crack arrest wascarried out on the weld defects to strengthen the research, and the research content mainlyincludes the following several aspects.(1) The finite element analysis software Ansys is used in0Cr18Ni9austeniticstainless steel and dissimilar materials of45#steel welding process and theelectromagnetic thermal crack arrest process to numerical simulation. By APDL languageand birth and death element method, the temperature field of weld process, thermal stressfield and residual stress field after cooling has been solved, and the cause of thermal crack,cold crack and the influence of welding parameters has been analyzed. The hot-electricaland mechanical three coupling calculation method is used to solve the electromagneticheat crack arrest of temperature field, stress field and strain field.(2) The laser welding and electromagnetic thermal crack arrest enhancingexperimental study is conducted on the heterogeneous material0Cr18Ni9austeniticstainless steel and45#steel.The TZ-2H digital ultrasonic flaw detector is used to test thewelding specimens,and carry out electromagnetic thermal crack arrest enhancingexperiment on those specimen of defects after detected. Comparison and analysis areconducted about the residual stress and mechanical properties, macro to micro fracture andEDS of the specimens before and after reinforcement. (3) The electromagnetic heat crack strengthening experimental study is conducted onAZ31magnesium alloy welded joint. Using the friction stir welding made of the multiplesets of AZ31magnesium alloy welding specimen. The TZ-2H digital ultrasonic flawdetector is used to test the specimens and electromagnetic thermal crack arrest enhancingexperiment is carried out on those specimen of defects after detected. Comparison andanalysis are conducted about the residual stress and mechanical properties, macro to microfracture and EDS of the specimens before and after reinforcement.In this paper, from two aspects of numerical simulation and experimental research,studies the electromagnetic thermal crack strengthening technology on the welding jointsof dissimilar materials and non-ferrous metal materials. The results are showed that: theelectromagnetic thermal crack strengthening technology can improve the mechanicalproperties of welded components, for the application of this technology in the field ofwelding has laid a foundation.