TIG welding Problems

TIG welding Problems

TIG welding poses particular problems for porosity issues. There is a demand for TIG welding for projects that require a quality weld bead; however, TIG rods do not contain flux that cleans and fights porosity. As a TIG welding expert, we are presenting different TIG Welding Problems so that you remain safe during TIG welding.

What are the causes of Porous TIG Welds?  In TIG welds, contamination is the leading cause of porosity. To allow contamination, TIG welding requires only four components: the electrode, the rod, the shield gas, and the material itself. Nevertheless, these elements can act as a pathway for contamination. Porous TIG Welds can also occur due to contamination.  There are 17 causes of pores in TIG welds, including:

TIG welding Problems

TIG is one of the most challenging processes to learn. A gas tungsten arc welding system (GTAW) or TIG welding method can fulfill many aesthetic, structural, code, and standard requirements. Here is an article that displays pictures and offers advice on how to prevent common TIG mistakes.

1. Poor gas coverage leads to contamination

One of the top problems in our TIG welding problems list is poor gas coverage leads to contamination. The lack of a shielding gas has resulted in contamination in this area. There are various causes for this, including not turning on the gas, having inadequate shielding, or having the gas blown away.

  • TIG welding typically requires 100 percent argon (or argon/helium blends for thick aluminum) on the gas cylinder label. When welds are performed using an argon/carbon dioxide mixture (commonly used for MIG welding), contamination will occur immediately.
  • There should be a minimum flow rate of 15 cubic feet per hour. Often, and incorrectly, welders believe that higher gas flows and pressures will give them better protection. Almost all gases are turbulent, creating swirling air currents (and arc wandering) that lure in unwanted pollutants. In general, err on the side of putting on low shielding gas rates to avoid turbulence.
  • All fittings and hoses should not leak. Any breach within a shielding gas line may pull air into the stream, contaminating the weld (and affecting the economy if gas escapes). Spray soapy water on the hose and its fittings later. You should replace a leaking component if bubbles form.
  • Even if your cylinder is complete, you have the correct type of gas, and there are no leaks, a moist tank might be the problem. The cylinder shields gas. It is rare for contamination to occur, but it can happen. You can resolve it by contacting your gas provider.

2. Welding aluminum in the wrong polarity/adjusting balance

Direct current electrode negative (DCEN) polarity was used for TIG welding. There is no weld penetration of the aluminum oxide layer, as you can see from the picture. Layer. Due to this interaction, the filler metal mixed with the partially melted oxide, causing the contamination you see here. When welding aluminum, always use alternating current (AC) when setting the polarity.

TIG welding in AC  consists of electro-positive (EP) and electro-negative (EN) phases, the EP portion blasting away aluminum oxide and the EN portion melting the base metal. Operators can adjust the EP to EN ratio using a feature called AC balance control. Weld puddles that show brown oxidation or flakes that resemble black pepper should be cleaned more frequently. In contrast, too much EP can result in excessive tungsten balling and too much etching. When TIG welding aluminum, wait until a shiny dot appears in the puddle before welding. Adding filler and continuing the process is now safe since the oxide has been removed. Filler added to the area after the oxide layer has not been removed adequately will cause contamination.

3. Weld graininess

As an example, the properties of a 4043 aluminum filler rod developed by one manufacturer may differ from those developed by another manufacturer. In some cases, the filler brand may need to be adjusted (if the application permits). There may also be damage to the rod (from an overabundance of an ingredient). You may even be welding with the wrong filler rod, that is, with 4043 instead of 5356.

It is important to verify the type of filler metal and clear the grease, oil, and moisture surface before welding.

4. Lack of fusion in the root

A T-joint or fillet weld can lack fusion at the root due to several factors: poor fits, torch distance (increased arc length), and improper handling of the filler rod, for example, multiples. Generally, this issue is seen more frequently in transformer-based machines since the arc tends to move in a path of least resistance between the two sides of the joint. By reducing arc length, you will be able to increase penetration and have better directional control. Under-filling the joint and welding too fast can also cause the joint to weaken.

Unlike traditional machines, inverter-based machines (especially those with advanced output controls, including frequency and pulse control) give you greater control over what happens in the arc. As a result, the arc cone becomes narrower, providing better control over the weld puddle (often deep penetration).

5. Craters

these types of craters are expected at the end of welding and result in cracking. When the welding power is reduced with too much rapidity or the filler rod is removed too shortly after the weld. When welding with a filler rod, keep feeding it at the end of the weld while reducing the current as slowly as possible to prevent crater cracks. Some TIG welders have crater and current control features that reduce the current at the end of the welding process. The result is an attractive weld bead.

6. Dirty base and filler metal

You should be familiar with the importance of cleaning the materials before welding when learning about welding. You took a photo that illustrates what happens when the mill scale remains on hot-rolled mild steel. Whether it is mill scale, aluminum oxide, grease, or dirt, You should remove the contaminant on base or filler metals. Remove all contaminants by grinding, brushing, and wiping. Moreover, it is easy to clean the aluminum with a stainless steel brush to avoid contamination from other metals.

Welds on mild steel look cleaner when cleaned adequately before welding. There is no cleaning of chrome-moly tubing before welding. At the same time, it illustrates the cleaning of chrome-moly tubing before welding.

7. Poor color on stainless

The poor color on stainless is another problem in our TIG welding problems list. A stainless steel weld shows discoloration caused by overheating, which is harmful to the material’s color and is also bad for its corrosion resistance and mechanical properties. When we make a mistake, we have no choice but to live with it. Except for scrapping it and starting over, there is nothing that you can fix it. Reduce the wattage, increase the travel speed or reduce the travel arc length to prevent overheating. Learn how to use pulsed welding if you have welding equipment with this capability. It is possible to minimize heat input with pulse welding to control weld puddles very effectively.

8. Sugaring on stainless steel

The weld becomes sugared (oxidized) when oxygen is present. To prevent sugaring, it is best to use shielding gas or reduce welding amperage.

9. Too much amperage on aluminum

An aluminum weld bead with too high an amperage is shown. Having a broader profile, ill-defined beads, and potential burn-through are all consequences. Moreover, Increasing travel speed or reducing amperage will help solve this issue.

10. Proper arc length control

A color change occurred due to an increased arc length in the middle of this aluminum welded bead. Voltage increases with increasing arc length. The arc length determines the overall heat input and distortion potential, reduces penetration, and affects the appearance of the weld bead. To improve the quality of your welds, practice holding an arc length of the same size.

Frequently Asked Questions

What is the defect caused by the high current in TIG welding?

Root and toe cracks

By using a high-current starting current and proper filler materials,  You can eliminate defects of this type. The toe crack occurs in the welded area when moisture is present in that area; it is one of the surface cracks, making it easy to detect.

Why does my TIG weld turn black?

You can make weld puddles as smooth and oxidation-free as possible by increasing EP. Likewise, too much EP results in tungsten balls, which is a problem for engraving. Start welding once you see a shiny surface on the puddle. You can tell when this is complete by adding filler metal to the hole.

What are the disadvantages of TIG welding?

The disadvantage of TIG welding

  • There is a time lag between TIG and other welding processes. …
  • A TIG welding operation requires highly qualified and experienced workers.
  • Light levels are high for welders, and eye damage can result.
  • Initially expensive.

Which defect is caused if the current is too low in TIG welding?

Causes Of Slag:

In the very low welding current density, slag will form as it cannot generate enough heat to melt the metal surface.

What is the welding defect which Cannot be seen visually?

A Welding Defect occurs within a component or at a depth within it is known as an internal defect. Since they are invisible, the impact is the same as that of the external ones. Incomplete fusion, slag inclusion, and poor penetration are among these defects.

What causes a lack of fusion in welding?

Welding parameters must be set incorrectly, the welder’s technique is poor, and there’s a tendency for magnetic arc blow. A lack of fusion can also be caused by inadequate cleaning of oily or scaled surfaces.

How do you overcome welding defects?

Remedies:

  1. Depending on the steel, preheat it.
  2. It would help if you adequately cooled welding areas
  3. Design joints properly.
  4. Purify.
  5. It is important to use the right metal.
  6. Ensure that the sectional area is sufficient.
  7. It’s important to weld at the correct speed and current.
  8. It would help if you filled the crater appropriately to prevent it from cracking.

What is the most detrimental weld defect?

An unstable weld connection is most likely to develop cracks. In most cases, cracks, no matter how small, are considered defects.

Final Verdict

As a TIG welder expert, I am responsible for presenting the TIG Welding Problems that every beginner or expert can face over time. I hope you will come across these hurdles and reach your destination. I present you with a GOOD LUCK for your established feature.

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