Study On The Narrow Gap Welding Technology Ofcable Type Welding Wire

After more than fifty years of development,narrow gap welding technology has been widely used in thick plate welding because of its good welding quality,high production efficiency,and low post-weld residual deformation.In the process of narrow gap welding of monofilaments,defects of lack of sidewall penetration are prone to occur.Some researchers proposed raising the heat input by increasing the monofilament diameter,increasing the sidewall penetration and improving the welding efficiency.However,when this method uses a narrow gap welding monofilament with a diameter of more than 1.6 mm,cracks,porosity,and other defects are likely to occur during welding.The weld joint toughness drops obviously.There are also scientific researchers who have proposed to increase the sidewall penetration by means of mechanically rotating arcs or electromagnetically rotating arcs,but these two methods have increased equipment costs,increased assembly difficulties,and reduced production efficiency.How to obtain high quality and reliable narrow gap welded joints more efficiently with simple and inexpensive equipment has become an urgent problem to be solved.With the improvement of traditional narrow gap welding materials,this paper proposes and implements a new welding method for narrow gap welding by using 2.4mm diameter cable type welding wire stranded from a special wire making process using seven 0.8mm sub-wires.The unique arc of the narrow gap cable type welding wire is used to increase the welding quality.The narrow gap cable type welding wire is used to increase the welding efficiency and energy efficiency.In this paper,a kind of ?2.4mm full solid cable type welding wire suitable for narrow gap welding was prepared by controlling the key technology of preparation of narrow gap cable type welding wire.This article compares?2.4mm solid single wire and ?2.4mm full solid narrow welding wire.The melting coefficient,deposition coefficient and comprehensive energy consumption of the gap-type cable welding wire are analyzed and researched on the characteristics of high-efficiency and energy-saving of the narrow-gap cable type welding wire.This paper comprehensively studied the reliability of narrow gap welding joints through nondestructive testing,process mechanical properties analysis,metallographic analysis and hardness testing.The results show that the key parameters such as tension force,twist distance,and rotation speed during the preparation of ?2.4 mm full solid narrow gap cable type weldingwire are set for the loose type,qualitative sizing and residual stress in the tanning process.The control of these technical points will eventually yield a wire with a uniform wire diameter,moderate elasticity,and low residual stress.The ?2.4mm full solid narrow gap cable type welding wire has a melting coefficient 27% higher than the ?2.4mm solid single wire,the deposition coefficient is 24% higher,the loss factor is about twice higher,the overall energy saving is 8.3% lower,and the integrated work time is reduced by 10%.The type of welding wire has more effective dry extension than monofilament,and the cross-sectional area is small,so the resistance heat is large and the melting is fast;the wire type welding wire has smaller surface tension than the monofilament droplet,and it is easier to produce the droplet transfer;the special arc rotation force of the cable welding wire.Accelerate droplet transfer.Under the appropriate process parameters,narrow gap welding butt joints of cable type welding wire were beautifully formed,and passed through penetrant test,X-ray test and ultrasonic test.The results of tension,bending,impact and hardness all met the application requirements.The quality of joint is reliable.