The influence of butt welding flange welding

The influence of tungsten welding flange

　　1. The influence of the tungsten tip

　　The tungsten tip is not sharp, and the arc drift is unstable, which destroys the argon protection zone and oxidizes the molten pool metal to produce pores.

　　2. The arc climbs up when starting the arc, causing poor protection

When using high-frequency arc ignition equipment, the temperature of the tungsten terminal is low when the arc is started, and it does not have sufficient thermal emission electron ability. The electrons are easily emitted from the place with oxide film, and climb along the electrode to find the place with oxide. At this time, the arc is elongated, and the protection effect of argon on the molten pool becomes worse. When the temperature of the tungsten electrode rises, electrons are emitted from the front end of the tungsten electrode, and the arc length becomes shorter accordingly. At this time, the oxide on the surface of the tungsten electrode can be eliminated by polishing it.

　　 Influence on the welding process of welding flange

　1. Groove cleaning

　　The groove surface and the 10mm range on both sides of the groove should be polished clean to avoid the magnetism generated by the arc during welding to suck the rust near the molten pool into the molten pool.

　　 2. The influence of welding speed

　　The welding speed is too fast. Due to the influence of air resistance on the shielding airflow, the argon airflow will bend and deviate from the electrode center and the molten pool, which is not good for the molten pool and arc protection.

　　3. Influence of arc extinguishing method

　　 The arc extinguishing method adopts attenuation current or adding welding wire to bring the arc to the groove side and lower the arc when extinguishing the arc. Do not stop the arc suddenly and cause the high temperature molten pool to separate from the effective protection of the argon gas flow, and avoid porosity or shrinkage in the arc crater.

　　4. The influence of welding current

　　 Butt welding flange welding current is too small, the arc is unstable, the arc drifts irregularly at the end of the tungsten electrode, destroying the protection zone. If the welding current is too large, the arc will disturb the airflow and the protection effect will be worse.

　　 5. The influence of the tungsten pole extension

　　 The tungsten electrode extends too long, and the protective effect of hydrogen on the arc and molten pool becomes poor.

Although there are many factors that cause pores in hand-to-hand welding flange tungsten argon arc welding, as long as you understand the characteristics of argon arc welding, and check the influencing factors one by one according to the actual situation, eliminate all the causes of argon arc welding. The factors that cause pores in the seam can improve the welding quality in actual production.