Determination of Optimal Pulse Current for ArcWelding
The manual and semi-automatic welding by pulse current (pulsing arc) is considered in the article. The advantages of welding by the pulsing arc are found out in comparison with welding by a constant arc. Using energetic calculation taking into account thermal balance at the electrode stub, optimal parameters of modulated current, such as frequency and duration of electrical pulses were established for different welding methods and regimes. By that stabilized heat, which needed for making melting drops, lower the level of metal splash and improve formation of the weld. Bibl. 12 (in English; summaries in English, Russian and Lithuanian).
Determination of pulse current optimal parameters for manual arc welding
Manual welding by pulsing arc (pulse current) is researched in the article. The advantages of welding by pulse current are found out in comparison with the welding by direct current. While using energy calculation and taking into account thermal balance at the electrode stub, optimal parameters of the modulated current, such as frequency and duration of electrical pulses were established for different welding regimes. This stabilizes heat, which is necessary for making melting drops, by lowering the level of metal splash and improves of the weld formation.
The effect of pulsed GTA welding on the residual stress of a stainless steel weldment
Abstract The objective of this study was to investigate the effect of pulsed GTA welding parameters on the residual stress of the weldment. Autogenous gas tungsten arc welding was applied on SUS 304 and SUS 310 stainless steels to produce a bead-on-plate weld. The residual stress was determined by using the hole-drilling strain-gage method of ASTM standard E837. The experimental results show that a greater pulse frequency, a larger pulse spacing, a greater amplitude ratio, and a greater duration ratio can reduce the magnitude of the residual stress in the austenitic stainless steel weldment. The residual stress of the 310 stainless steel weldment is greater than that of the 304 stainless steel weldment under the same welding conditions because of its lower thermal conductivity and thermal diffusivity. The experimental results also showed that pulsed current welding has a smaller range of the tensile residual stress zone as compared to that of constant current welding because of its lesser amount of heat input.