Numerical Simulation And Experimental Analysis Of20Steel One Side Welding Both Sides Formation

Single-side welding and double-side molding technology based on substrate has been widely applied in important structures such as boiler with special requirements, pressure vessel, pressure piping. It is difficult for the choice of substrate to set down welding procedure, which is affected by member size, material properties and so on. Therefore, it is necessary to study the single-side welding and double-side molding technology without substrate. Simulation of welding has developed rapidly in order to reduce the experimental cost while research on simulation of single-side welding and double-side molding technology was very little. In this paper,20steel was welded by single-side welding and double-side molding technology without substrate, and carried out numerical simulation and test analysis.FEA software ANSYS with written in APDL (ANSYS Parametric Design Language) language is used to simulate eight groups parameters and get the influence factors of temperature field. The result shows that the faster welding speed, the shorter heating time of heat source, the less input of thermal energy, the lower maximum temperature. The energy of heat source got dispersed as the arc radius increasing, the maximum temperature got lower. The input heat became increasing and the temperature got high as the current and voltage increased. Then temperature field was analyzed from five set of parameters, stress field and experimental analysis are separately carried out from optimal three group parameters. The analysis of welding temperature field showed that too little input thermal energy in the first parameter can't take an effect on one side welding and double side forming while too much input thermal energy in the fifth group parameters will bring about defects such as air bubble, incomplete fusion. Stress field and experimental analysis were carried out for three group parameters left.The analysis of welding residual stress field indicated that the stress of weld zone and heat-affected zone are tension stress, of base metal is pressure stress, Tension stress of weld zone is close to the yield limit, which is matched with that of actual result. The residual stress of fourth group parameters is least and the result is best.The result of tension test stated clearly that fracture location of all the samples were in the base metal, the average tensile strength of the fourth sample was569Mpa while the average elongation was16.1%. The fracture morphology analysis shows that there are a number of deep dimples with small size in the microstructure of the fourth sample which proved that resistance of crack propagation is comparatively large, the toughness is good. So, the welding procedure of the fourth group parameters is best.Making a comprehensive analysis of above results, we can conclude that there is a close correlation between numerical simulation of welding and experiments results.