What should be paid attention to when welding the nozzle of the insulating cup?

You know what? In fact, there are many types of insulation cup equipment, such as the nozzle welding machine and necking machine, which are common in our daily life. This time, we will introduce to you what needs to be noticed in nozzle welding. If you are interested, you can have a look.
What should be paid attention to when welding the nozzle of the insulating cup? Here is an introduction for you
1) When the back side is filled with argon for protection, the air in the pipe has been in eddy current motion and is difficult to be discharged. Even if the replacement time is extended, the oxygen content can reach<0.01% (volume fraction) when the inner seal is fully sealed, but after opening the groove and starting welding, the oxygen content will rise to 0.05% (volume fraction) or even higher. The high oxygen content causes the oxidation of the weld bead back surface to turn blue or purple.
2) In the field construction, the welder generally uses a simple argon arc welding gun with scratch and striking arc. This kind of welding gun causes the high-temperature weld bead to lose the protection of argon instantaneously after the arc is broken, resulting in the oxidation and discoloration of the joint at each arc stop.
3) Each time the arc joint is started, the air enters the inner groove through the open welding groove. At this time, the oxygen content in the inner groove is high, and the high-temperature weld bead is easy to be oxidized locally.
4) During welding of filler and cover layer, the back of weld bead will also be oxidized and discolored due to high welding current, high welding heat input or high interpass temperature.
5) The argon with low purity and high oxygen content has poor protection effect on the weld.
6) The thermal conductivity of stainless steel is poor, which is 1/3 of that of steel. During welding, the heat cannot be dissipated, resulting in higher temperature of weld bead and heat affected zone, which is easier to be oxidized.