Question: Why Are My TIG Welds Black?

Why do welds turn blue?

On stainless steel, for example, any color in the weld or HAZ shows that an oxide layer has formed, which can affect corrosion resistance.

The darker the color is, the thicker the oxidization.

The colors follow a predictable pattern, from chrome to straw to gold to blue to purple.

Corrosion resistance..

What are the disadvantages of TIG welding?

Disadvantages Of TIG: It will take a lot of time when welding. Welding with this welding machine is time consuming and the speed is slower than any other welding machines available in the market as well. It also has got lower filler deposition rate as well. It has got high initial cost.

Whats stronger MIG or TIG?

Bottom Line. TIG welding produces cleaner and more precise welds than MIG welding or other Arc welding methods, making it the strongest. That said, different welding jobs may require different methods, while TIG is generally stronger and higher in quality, you should use MIG or another method if the job calls for it.

Why do my TIG welds look dirty?

1. Poor gas coverage leads to contamination. The weld here shows contamination caused by lack of shielding gas, which can happen when the shielding gas is not turned on, there is either too little or too much gas shielding, or the gas is blown away.

Why are my stainless TIG welds black?

Response from weldingtipsandtricks on stainless steel welds. Discoloration is oxidation. It is just a matter of the argon shielding envelope leaving the hot metal before it has a chance to cool enough to not oxidize. … Stainless has a tendency to bond really well with low heat as long as it is clean.

What causes pinholes in TIG welds?

One of the most common reasons for welding pinholes is that your cylinder is almost out of gas. This causes an uneven gas flow to the arc and creates pinholes. If there is a lot of moisture in the air, it can cause water molecules to get trapped in the weld that creates pinholes.

Why are my welds black?

When magnesium is vaporized by the arc’s heat and comes in contact with oxides, black soot forms. A proper gun push angle of approximately 15 degrees helps keep gas coverage at the leading edge of the weld pool, which reduces soot. Your shielding gas should be pure and moisture-free.

Why are my TIG welds GREY?

Due to overheating of metal tig welding becomes grey or dull in color and that also degrades its corrosion resistance and mechanical properties also. To get rid of grey or dull color you need to increase travel speed or shorten the arc length.

What metals Cannot be TIG welded?

Some examples of material combinations that cannot be fusion welded successfully are aluminum and steel (carbon or stainless steel), aluminum and copper, and titanium and steel. Nothing can be done to alter their metallurgical properties. That leaves changing your process.

How can you tell if a weld is bad?

Signs of a bad weld:Excessive grain growth.Presence of “hard” spots.Underside of weld has insufficient penetration.Porosity.Cracking.Excessive globules of metal.Incomplete fusion.Oversized or undersized welding line.More items…•

What is the cause for poor weld bead Colour in TIG welding process?

The grainy appearance of the weld bead is typically caused by welding too hot causing too much base metal dilution. (1) Find that “sweet spot” that is not too hot and not too cold, and this graininess will go away. (2) You may have the wrong type of filler metal (4043 instead of 5356).

What color tungsten is for stainless steel?

Ceriated (Color Code: Orange) Like thorium, it is best used to weld carbon steel, stainless steel, nickel alloys, and titanium, and in some cases it can replace 2 percent thoriated electrodes. Ceriated tungsten has slightly different electrical characteristics than thorium, but most welders can’t tell the difference.

Why is my Tungsten turning black?

If the tungsten electrode turns from its normal color of light gray to a shade of purple or black, that is an indication to increase post-flow time even more. In addition to causing various weld puddle troubles, contaminated tungsten electrode is also the leading cause of an unstable arc.

What does a good TIG weld look like?

A good-looking weld is clean and is the same color as the base metal, both inside and out-. The width of the bead should be consistent and have an attractive face surface profile.