An essential component to the welding process is all the different types of gasses and how to properly handle and store them.
Welding gases play a roll in over all appearance as well as quality of your welds so do not over look this.
Argon is a single-atom gas widely used in TIG and MIG welding processes. Argon is used to keep the heat from the arc more focused, this is why you can tend to get under cut due to the lack of heat on the outer edges of your weld puddle.
Also a single-atom gas, Helium is mostly used for TIG welding (GTAW). Although Helium acts the opposite of Argon as it allows the arc to be hotter and spread wider.
Although Nitrogen is possibly the least used in welding shielding gas mixes, it still plays a roll in helping with the formation of austenite as well as its corrosion resistance in duplex and super-duplex steels.
Used as a mixture gas for welding, making up for no more than 10% of the weld shielding gas mix. Surface bead will become hotter and wider with Hydrogen mix. This makes it good for Stainless Steel metals as it promotes the removal of oxidation on stainless and it allows better heat input.
Hydrogen may also be used in larger mix percentages when cutting stainless steel. Using this welding gas mix in the 30% + helps with a higher capacity cut that doesn't create lots of slag.
Used normally as a mixture of less than 10%, Oxygen for a welding gas creates a wide and shallow weld profile. The benefits you will see with adding Oxygen when welding will be a better wetting in of the weld puddle and spray transfer facilitation.
Mostly used with MIG Welding (GMAW) or FCAW, Carbon Dioxide will break apart in the heat of the arc. This interaction allows for oxidization of the base metal as well as de-alloying the weld puddle. Bead profile tends to be similar width to depth ratio with good penetration all around.
Colorless, odorless and highly flammable. Acetylene will normally have a garlic smell added to it so that you can detect a leak. Acetylene is used in welding for anything from brazing to cutting and has a primary flame heat of 6,300 F.
Using this gas can be very dangerous so make sure your never running more than 7psi of pressure. Also another thing to note is some of these fueling gasses will have reverse threads.
Propane gas is a colorless, liquefied gas that has a natural gas smell. Compared to Acetylene, Propane has a low flame temperature and requires more pre-heat for cutting applications. Propane is used in cutting when quality of cut is not important. Propane is a more cost efficient gas than Acetylene or Propylene.
Like Propane, Propylene is also a colorless liquefied gas that has a sweeter smell to it. This gas has a high heat in the primary and secondary flame. Propylene is basically a mix between Propane and Acetylene to get the hotter primary flame of Acetylene while still getting the hotter secondary flame like Propane.
In the welding industry, shielding and cutting gasses are essential for work production and success. Remember that handling these gasses under very high pressures can be dangerous and you must take all the proper safety precautions.
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