Study On Technology And Quality Improved Of Arc Stud Welding Induced By Arc Stabilizer

For the stud welding of medium-diameter hollow Q235 stud and 45 steel,there are some welding problems due to the differences in welding characteristics and the properties of the base material,including arc deflection,arc instability during welding,poor joint forming quality after welding,and low joint strength.Aiming at the above welding defects,the research on arc stabilizer induced stud welding technology and quality improved is carried out in this paper.The results show that this technology can not only effectively solve the welding defects of stud welding,also can effectively improve the mechanical properties of the joint,making the joint both beautiful and practical.Through the analysis of temperature field simulation and measured data,it is shown that the use of arc stabilizer not only provides additional heating input for the melting pool,but also plays a certain role in heat preservation of the joint,which slow down the cooling speed of the melting pool and avoid generating numbers of brittle and hard tissues by excessive cooling speed.Carring out research of arc stabilizer to induce arc stud welding technology.The optimal combination of process parameters were obtained through orthogonal test.Including welding current 600 A,welding time 400 ms,arc stabilizer content 0.26 g,the average value of joint shear strength is 307.75 MPa,the average value of external height of stud is 27.73 mm.The fracture form of joint under the optimal parameters is ductile fracture.Pores,cracks,unwelded defects have not been found in the weld joint.Compared with direct stud welding,the morphology and quantity of martensites in the weld changed.The quantity of needle martensites decreased as a small amount of strip martensites generated,which improved the toughness of the weld.The maximum impact power of the joint can reach 87 J.It suggests that the use of the arc stabilizer have the effect of promote the arc emissional ability and expand the arcing area,so that eliminating the arc deflection and keeping arc stable.Under the action of heat and arc force to improve the liquidity in molten pool.Obtaining continuous weld seam and welded joint molten pool is full of filler metal.Carring out research of molten pool protection technology.Using modified arc stabilier to add active elements into molten pool can change the molten pool surface tension so as to change the state of molten pool convection and melt dripping transition state by the function of each element.On the edge of the molten pool forming protective atmosphere and in the center of the molten pool making melt drop transition stable to reduce the splash.According to the quality control test of the joint,the optimal process parameters were obtained.Incuding welding current 550 A,welding time 450 ms,arc stabilizer content 0.20 g.The average value of the joint shear strength is 330 MPa,and the strength is improved.The average height of stud forming is 27.96 mm.Obtaining continuous welding seam,welding seam wrapped by uniform and full convex table.The appearance of joint is more beautiful.The fracture form of joint is ductile fracture.The quantity of brittle phase in the weld is significantly decreased and the grain is refined.The impact power of the joint can reach up to 95 J.