TIG welding, also known as Gas Tungsten Arc Welding (GTAW), is a popular welding process known for its precision and high - quality welds. As a Metal Welding supplier, I've seen my fair share of TIG welding problems and have learned how to troubleshoot them effectively. In this blog, I'll share some common TIG welding issues and how you can fix them.
1. Poor Arc Starting
One of the most frustrating problems in TIG welding is when the arc won't start properly. There are a few reasons why this might happen.
Contaminated Tungsten Electrode
The tungsten electrode is a crucial part of the TIG welding process. If it's contaminated, it can prevent the arc from starting. Contamination can come from things like touching the electrode with bare hands, which transfers oils and dirt. To fix this, make sure to handle the tungsten electrode with clean gloves. If it's already contaminated, you can re - grind the electrode to a clean surface.
Incorrect Tungsten Preparation
The shape and angle of the tungsten electrode tip play a big role in arc starting. A blunt or incorrectly shaped tip can make it difficult for the arc to form. You should grind the tungsten to a sharp point, with the angle depending on the welding application. For most general welding, a 30 - 45 degree angle works well.
Gas Flow Issues
Insufficient gas flow can also cause problems with arc starting. The shielding gas is necessary to protect the weld area from oxidation. If the gas flow is too low, the arc may not start or may be unstable. Check your gas regulator to make sure it's set to the correct flow rate. Usually, a flow rate of 10 - 20 cubic feet per hour (CFH) is suitable for most TIG welding applications.
2. Weld Porosity
Porosity in the weld is another common problem. It looks like small holes or voids in the weld bead and can weaken the weld.
Gas Shielding Problems
Just like with arc starting, gas shielding is key to preventing porosity. If the shielding gas is not flowing correctly or if there are drafts in the welding area, the weld can be exposed to oxygen and nitrogen, which causes porosity. Make sure your welding area is well - shielded from drafts. Also, check for any leaks in the gas hose or connections.
Contaminated Base Metal
The base metal can also be a source of porosity. If it's dirty, rusty, or has oil on it, these contaminants can release gases during the welding process, creating pores in the weld. Before welding, clean the base metal thoroughly using a wire brush or a solvent.
Incorrect Welding Parameters
Using the wrong welding parameters, such as too high a welding current or too slow a travel speed, can also lead to porosity. Adjust your welding current and travel speed according to the thickness of the base metal and the type of electrode you're using.
3. Weld Cracking
Weld cracking can be a serious issue as it can compromise the integrity of the weld. There are two main types of cracking: hot cracking and cold cracking.
Hot Cracking
Hot cracking occurs during the solidification of the weld metal. It's often caused by high levels of impurities in the base metal or filler metal, or by incorrect welding parameters. To prevent hot cracking, use high - quality base and filler metals. Also, make sure your welding current and travel speed are set correctly to avoid over - heating the weld area.
Cold Cracking
Cold cracking happens after the weld has cooled. It's usually due to hydrogen absorption in the weld metal. To prevent cold cracking, pre - heat the base metal before welding. This helps to reduce the cooling rate of the weld and allows any hydrogen to escape. You can find more information on proper welding techniques at High Quality Structural Steel Fabricators Stamping Bending Welding Fabrication.
4. Weld Spatter
Weld spatter is the tiny droplets of molten metal that fly off the weld bead during the welding process. It can be messy and can also cause problems with the appearance of the weld.
Incorrect Current and Voltage Settings
Using the wrong current and voltage settings can cause excessive spatter. If the current is too high or the voltage is too low, the metal will transfer in a less - controlled way, resulting in spatter. Adjust your welding machine settings to find the right balance for the base metal thickness and electrode type.
Contaminated Electrodes or Base Metal
As with other problems, contamination can also lead to weld spatter. Make sure your electrodes and base metal are clean before welding.
5. Excessive Penetration or Lack of Penetration
Excessive Penetration
Excessive penetration can occur if the welding current is too high or the travel speed is too slow. This can cause the weld to burn through the base metal. To fix this, reduce the welding current and increase the travel speed.
Lack of Penetration
On the other hand, lack of penetration is when the weld doesn't fully fuse with the base metal. This is often due to a low welding current or a fast travel speed. Increase the welding current and slow down your travel speed to ensure proper penetration. You can learn more about achieving the right penetration in High Accuracy Jig Welded Parts Fabrication and Welding.
6. Tungsten Inclusions
Tungsten inclusions are bits of tungsten that get into the weld. This can happen if the tungsten electrode touches the molten weld pool.
Operator Technique
Improper operator technique is the main cause of tungsten inclusions. Make sure you keep the tungsten electrode at the correct distance from the weld pool. A good rule of thumb is to keep the electrode about 1/8 to 1/4 inch away from the weld pool.
Incorrect Amperage
Using too high an amperage can also cause the tungsten to melt and get into the weld. Adjust your amperage according to the thickness of the base metal and the type of tungsten electrode you're using.
7. Aluminum Welding Specific Problems
When it comes to Custom Aluminium Fabrication Bending Cutting Aluminum Welding, there are some unique challenges.
Oxide Layer
Aluminum has a tough oxide layer on its surface. This oxide layer has a much higher melting point than the aluminum itself. If it's not removed before welding, it can cause problems with arc starting and weld quality. Use a stainless - steel wire brush to clean the aluminum surface before welding.
Heat Dissipation
Aluminum is a good conductor of heat, which means it can dissipate heat quickly. This can make it difficult to maintain a stable arc and achieve proper penetration. You may need to increase the welding current or use a pre - heat technique to compensate for the heat dissipation.
If you're facing any of these TIG welding problems or need high - quality welding products, don't hesitate to contact us for a procurement discussion. We're here to help you get the best results from your welding projects.
References
- AWS Welding Handbook, American Welding Society
- TIG Welding: Principles and Practices, various industry experts
