Effect of TIG current on microstructural and mechanical properties of 6061-T6 aluminium alloy joints by TIG–CMT hybrid welding

In a method for controlling pulse arc welding where an arc is created between a wire and a base material, a pulse waveform different from the pulse waveform for steady-state welding is outputted when a predetermined time has passed since short-circuit welding control was started at arc start, and after a sufficiently large melt pool is formed, the pulse waveform for the steady-state welding is outputted This reduces the generation of spatters after an arc is created and until the arc is stabilized

Arc welding control method

Disclosed is an arc welding method wherein when a weld-ending signal is input while arcing, the welding wire is accelerated, causing a short between the welding wire and a parent material; thereafter the welding wire is retracted, and when a predetermined wire retraction speed is attained, the wire supply speed is fixed at the predetermined wire retraction speed; after retracting for a predetermined period of time, the supply of welding wire is stopped; and considering the time the short began during retraction of the welding wire as the starting point in time, a fixed, predetermined welding current is output for a predetermined length of welding time, and then welding output is stopped.

Arc welding method and arc welding device

An arc welding control method performs welding of a work by alternately repeating a short-circuit period for short-circuiting a welding wire to a work and an arc period for regenerating an arc to perform arc discharge. The control is performed so that the welding output current immediately after regeneration of the arc is maintained higher than the welding output current immediately before the arc regeneration for a predetermined period of time.

Arc welding control method and arc welding device

VPPAW penetration monitoring based on fusion of visual and acoustic signals using t-SNE and DBN model

On TIG-MIG hybrid welding process (TIG: DCEN and MIG: DCEP), the stability of MIG arc can be kept even in pure inert shielding gas by the effect of hybridization with TIG arc, and it becomes possible to achieve the new welding method which has both merits of high quality as TIG welding process and high efficiency as MIG welding process. In this report, we performed two experiments mainly as follows to solve two problems: (1) Analysis of output from TIG power source in hybrid welding state to prove experimentally the existence of direct current path which flows between TIG cathode and MIG anode via in hybrid arc plasma. (2) Measurement of actual heat input based on evaporation amount of liquid nitrogen to investigate detailed heat source property of this process. As results, it was shown that output of TIG power source in hybrid welding condition is lower than it in single TIG welding, and the heat efficiency in hybrid welding condition decreases about 10 % rather than it in single heat source of TIG or MIG arc. Moreover, in specific condition that value of TIG current is lower than value of MIG current, output of TIG power source becomes entirely zero even though TIG arc shape is observed clearly, and thus, the stability of MIG arc is lost then. It can be said that these findings reveal the existence of direct current and explain one of mechanisms that TIG arc can control the arc stability and heat input of MIG arc.

Study for the mechanism of TIG-MIG hybrid welding process

A squeezing detection control method is provided for consumable electrode arc welding. The method includes a step of detecting a droplet squeezing phenomenon by checking that a change in a voltage or resistance between the consumable electrode and base material reaches a squeezing detection reference value, and a step of executing output control for rapidly decreasing a welding current passing through a short-circuited load when the squeezing phenomenon is detected, so that arc re-striking occurs in a state of low current. The squeezing detection reference value is set to a first value during the electrode positive polarity, and set to a second value during the electrode negative polarity. The second value is different from the absolute value of the first value, and each of the first and second values is set such that the resultant welding state is satisfactory.

Squeezing detection control method for consumable electrode arc welding

To start consumable electrode arc welding, an initial current is supplied to a welding wire after causing the welding wire to contact a base material and retracting the welding wire from the base material. In this manner, an initial arc is generated. The welding wire is retracted continuously for an initial arc lift period Ti with the initial arc maintained. Afterwards, the initial arc is switched to a steady arc. A predetermined weld pool formation period Tp is set after the initial arc lift period Ti. In the weld pool formation period, a weld pool formation current greater than the initial current is supplied with the initial arc maintained and the welding wire is caused to proceed and fed to the base material. In the weld pool formation period, a weld pool is formed by the initial arc without allowing the welding wire to release droplets and contact the base material. By this method, the initial arc is switched to the steady arc state after the weld pool has been formed. This suppresses generation of spatter caused by transfer of the droplets to the base material.

Arc start control method

PROBLEM TO BE SOLVED: To improve accuracy of detecting constriction in a method for detecting/controlling constriction in consumable electrode arc welding attended with a short circuit. SOLUTION: In this method for detecting/controlling constriction in consumable electrode arc welding, the constrictive phenomenon of a droplet as a sign phenomenon of regeneration of arc from a short-circuit state is detected by that a change in a voltage or resistance value between a consumable electrode and a base metal reaches a reference value Vtn for detecting the constriction, thereby a welding current is rapidly reduced. The constriction detecting time is detected for each short-circuit, storing the detecting time from the current point of time retroactively to the prescribed number of time in the past (MT). When the number of each stored constriction detecting time (Mt) below the minimum value inclusive is not less than the minimum number, the reference value Vtn for detecting the constriction is decreased by the variation ΔF. When the number of each stored constriction detecting time (Mt) above the maximum value inclusive is not less than the maximum number, the reference value Vtn for detecting the constriction is increased by the variation ΔF. Thus, the reference value Vtn for detecting the constriction is optimized. COPYRIGHT: (C)2007,JPO&INPIT

Method for detecting/controlling constriction in consumable electrode arc welding

A welding current controlling method is provided for an arc welding process using a consumable electrode and including an alternate repetition of a short-circuiting state and an arc generating state occurring between the consumable electrode and a base material. In the method, a neck detection is performed for the molten electrode in the short-circuiting period of time to determine if a new arc is established between the consumable electrode and the base material. Upon detection of the neck, the welding current is sharply decreased. After the new arc is established, the welding current is increased from a low level to a high level with a predetermined inclination selected for reducing vibration to the molten pool.

Tetsuo Era

Papers

Study for the mechanism of TIG-MIG hybrid welding process

Squeezing detection control method for consumable electrode arc welding

Arc start control method

Method for detecting/controlling constriction in consumable electrode arc welding

Welding current controlling method in arc welding process using consumable electrode upon detection of constriction