MIG welding is a welding process in which an electrode produces heat to melt the metals. And, it also combines the two base materials. Moreover, shielding gas is also sent via a welding gun. Further, the MIG welding gas protects the weld pool from contamination. Furthermore, MIG is the abbreviation for metal inert gas.
Argon and Helium are the inert gases used in welding. Here, inert means that they are non-reactive to others.
Select The Right Gas
MIG welding applications provides diversity in choices of shielding gases. Therefore, one needs to evaluate the welding goals to select the gas. Thus, the expense on the gas, preparation, and post-weld clean up finished well properties, the base material, transfer process of the weld, and the productivity goals are to look upon, to select the gas.
Thus. the most common gases used in MIG welding are Argon, Helium, Carbon dioxide, and Oxygen.
Carbon Dioxide (CO2) is the most common reactive gases used in MIG welding. Further, CO2 is the only gas to be able to use in its purest form. Moreover, CO2 is also the least expensive shielding gas. Thus, making an attractive choice for MIG welding.
Though of reactive nature, Oxygen is mix in portions of nine percent or less. Thus, it helps in improving the penetration and arc stability in low alloy, mild carbon, and stainless steel, and weld pool fluidity. Further, it causes oxidation of the metal to weld. Therefore, it is not recommended to use with Copper, Magnesium, and Aluminium or other exotic metals.
Just like pure Argon, Helium is used with stainless steels, and with non-ferrous metals. Because it produces a full, in-depth penetration profile, Moreover, Helium is used in ratios between 25 — 75 percent Helium to 75 — 25 percent Argon. Furthermore, it works great with thick metals.
MIG Welding Gases Characteristics
- Argon gas possesses shallow broad penetration and also a very smooth fluid-like arc.
- Further, the hot weld with good weld productivity is producing by Helium and mild penetration with a fluid arc.
- Also, Carbon Dioxide produces a penetration which is deep and narrow with a stiff harsh arc that works well in welding.
- Also, Oxygen, when mixed in Helium or Argon in small amounts, helps to deepen the weld penetration and also stiffens the characteristics of arc.
- Moreover, Helium added to any mix makes the arc heat up more.
MIG Welding Gas
Carbon Dioxide does the welding of carbon steel. Since, it produces the deepest penetration, the roughest weld, and the most smoke.
MIG Welding Gas For Stainless Steel Welding
Welding of stainless steel is done with C2 or 2% Carbon Dioxide and 98% Argon. Though, in some situations, there is a tri-mix shielding gas which contains 2.5% Carbon Dioxide, 7.5% Argon, and 90% Helium.
MIG Welding Gas For Aluminium Welding
Argon, though with an exception, is used for Aluminium welding. Thus, if the Aluminium is thicker than half an inch, then add Helium to it.
I hope this article delivered you your required information.