1. Core principle: Why must we use argon?
During the welding process, the metal is like red-hot iron at high temperatures. If it is not protected, it will immediately combine with the oxygen and nitrogen in the air. The result is that the weld will have pores and cracks, and the strength is simply not enough.
TIG welding is a welding method that uses argon as a protective gas. Argon is an inert gas with extremely stable chemical properties and does not react with any metals. It is like an invisible protective shield that tightly covers the arc and molten pool and isolates the bad things outside, so that the welded seam is strong and beautiful.
2. Equipment and parameters: Control the “heat” just like cooking
TIG welding equipment mainly consists of a welding gun system and a gas circuit. The tungsten electrode inside the welding gun is the key to generating the arc; the gas path is the runway for argon gas, which comes out from the gas cylinder, passes through the pressure reducing valve and flow meter, and is finally sprayed out from the welding gun to protect the molten pool.
Parameter configuration is particularly important. If the parameters are incorrect, the welding effect will definitely be poor.
Current and voltage: When welding thin steel plates, the current should be small, otherwise it will be welded through at once; thick steel plates must be welded with high current, otherwise the welding will not penetrate. Voltage is usually matched with current.
3. Specification setting: These parameters directly affect the quality of welds
The welding position and material thickness are different, and the parameters need to be adjusted accordingly.
1. Current selection: The current can be larger during flat welding; during vertical and overhead welding, the current must be appropriately adjusted to prevent the molten pool from flowing down.
2. Argon gas flow rate: If the flow rate is too small, the protection effect is not good, and the molten pool is easily oxidized; if the flow rate is too large, it is not only wasteful, but also easily blows the molten pool into a mess.
Reference value: The argon gas flow rate for manual argon arc welding is generally controlled at 8 to 15 liters/minute.
4. Quality assessment: You can tell the level of quality just by looking at the color.
In fact, you can almost guess whether the weld quality is good or not by looking at the color. Color is a barometer of protection effectiveness:
Silver white/golden yellow: The protection effect is excellent and the quality is absolutely no problem (this is the highest level).
Blue/Gray: A little oxidized, the protection effect is average, and parameters need to be adjusted.
Blackening: The protection is not done well at all, and there must be defects inside the weld.
After the welding is completed, don’t turn off the gas in a hurry. Take a look at the color and you will probably know how well you did the welding. Many novices turn blue when welding, often because the argon gas flow is insufficient, or the welding gun moves too fast, and the protection time is not enough.
5. Tungsten electrode selection: Choosing the right tungsten electrode is half the battle.
Tungsten electrodes of different colors have different personalities and applicable scenarios.
Thoriated tungsten electrode (RED): strong electron emission capability, easy arc ignition, and stable arc. Although it is a little radioactive, it has little impact on the human body as long as it is handled properly.
Cerium tungsten electrode (GRAY): It has almost no radioactivity and is easy to start an arc. It is currently the most widely used environmentally friendly electrode. The disadvantage is that its ability to withstand current is relatively poor.
Pure tungsten electrode (GREEN): high melting point, but difficult to start arc and poor arc stability. Generally used in AC argon arc welding, such as when welding aluminum.
Lanthanum tungsten (SKY BLUE): used for AC and DC, stable performance and non-radioactive; yttrium tungsten is used for high current thick plate welding, with excellent high temperature stability. Price is slightly higher
Zirconium tungsten electrode (WHITE): mainly used for high-frequency AC welding of aluminum and aluminum alloys, with strong anti-pollution ability. The welding performance under AC is better than that of pure tungsten
6. Operation skills: This is the real “hands-on skill”
This part is real Kung Fu, you have to practice it slowly, but you need to know the technique first.
1. Arc ignition: Never touch the tungsten electrode directly to the workpiece, otherwise the tungsten electrode will stick and easily produce pores. Use high-frequency arc ignition, or lightly touch the workpiece and leave immediately.
2. Arc closing: Do not take away the welding gun at once, otherwise arc craters will occur and cracking may occur. Slowly reduce the current, or stay longer at the arc closing point to fill the arc crater.
3. Gas control:
(1) Supply air in advance: Before welding, supply air 2-3 seconds in advance to drain the air cleanly.
(2) Delayed gas stop: After welding, do not turn off the gas in a hurry. Wait for 2-3 seconds before stopping the gas to ensure that the high-temperature molten pool is protected during the cooling process.
7. Safety protection: Life is at stake, don’t be careless
Last but not least — Safety comes first.
1. Cleaning before welding: Oil, rust, and oxide scale on the surface of the workpiece must be cleaned. It can be polished with sandpaper or cleaned with a wire brush, otherwise pores and cracks will occur during welding.
2. Operation protection:
(1) Eyes: You must wear a welding mask and choose a suitable filter, otherwise strong light and ultraviolet rays will damage your eyes.
(2) Body: Wear gloves and protective clothing to prevent burns.
(3) Breathing: There must be ventilation equipment at the site to exhaust the smoke and dust. Inhaling too much will cause harm to the body.
Post time: May-09-2026