Acetylene (C2H2) is a colorless, highly flammable gas. Mostly used for oxy-fuel applications, acetylene has a high heat release in the primary flame and a low heat in the secondary flame. It has the hottest flame temperature of the commercially available fuel gases (6,300 °F/3, 480 °C) and is an excellent choice for welding, brazing and cutting of steel alloys less than 1 inch thickness.
Interesting Info: An Acetylene cylinder has a tank pressure of 250 psi at 70 Degrees F
Air is a colorless, odorless, nonflammable gas. Industrial air is used in air carbon arc gouging and in plasma arc cutting (PAC) processes.
Colorless, odorless, tasteless and non-toxic, argon (Ar) is a noble gas that comprises 0.93% of the earth's atmosphere. Argon can provide an inert and clean environment free from nitrogen and oxygen for annealing and rolling metals and alloys. In the casting industry, argon is used to flush porosity from molten metals to eliminate defects in castings. In the metal fabrication industry, argon is used to create an inert gas shield during welding. Argon is frequently blended with carbon dioxide (CO2), hydrogen (H2), helium (He) or oxygen (O2) to enhance the arc characteristics or facilitate metal transfer in Gas Metal Arc Welding (GMAW or MIG).
Because 100% argon can be used to TIG weld all metals and thicknesses you only need one type of gas in your shop to handle all of your welding projects. MIG welding aluminum is different than welding steel when it comes to shielding gas requirements. For aluminum, 100 percent argon is the gas of choice.
Carbon Dioxide (CO2) is a tasteless, colorless, odorless, nonflammable gas. It is commonly utilized with argon (Ar) as a shielding gas during welding or in some cases it is used in pure vapor state. This prevents atmospheric contamination of molten weld metal during gas shielded electric arc welding process.
Helium (He) is the second lightest elemental gas next to hydrogen. Colorless, odorless, tasteless, nontoxic and chemically inert, helium is nonflammable and has a high thermal conductivity. It is used to create an inert gas shield and prevent oxidation during welding of metals such as aluminum, stainless steel, copper and magnesium alloys. The addition of helium generally increases weld pool fluidity and travel speed.
Hydrogen (H2) is the lightest of all gases. Colorless, odorless, tasteless and nontoxic, hydrogen exists as a gas at atmospheric temperatures and pressures. In metal fabrication, hydrogen serves as a protective atmosphere in high-temperature operations such as stainless steel manufacturing; commonly mixed with argon for welding austenitic stainless. Hydrogen is used to enhance plasma welding and cutting operations.
Nitrogen (N2) is a diatomic gas which comprises 78% of the earth's atmosphere. Colorless, odorless, tasteless, and nontoxic, nitrogen exists as a nonflammable gas at atmospheric temperatures and pressures. Nitrogen is utilized as a purge gas with stainless steel tube welding. Nitrogen can enhance plasma cutting, food processing, heat-treating. Small additions to argon based shielding gases can be used for welding stainless steel by the Gas Metal Arc Welding (GMAW or MIG) process.
Oxygen (O2), which comprises 21% of the earth's atmosphere, supports life and makes combustion possible. Colorless, odorless and tasteless, oxygen is used to support oxyfuel cutting operations. Oxygen may be added in small quantities to shielding gases. Oxygen is also used as the plasma cutting gas (with Hafnium electrodes) on carbon steel.
Propane (C3H8) is a colorless, flammable, liquefied gas with a natural gas odor. The flame temperature of the oxy-propane flame is lower than acetylene and propylene. The primary flame releases low BTU when compared to propylene or acetylene, which increases preheat time. Propane is commonly used by scrap yards for cutting carbon steel, where the cut quality is not critical. Where cut quality is not a concern, propane may be a cost-effective fuel gas.
Interesting Info: A Propane cylinder has a tank pressure of only 110 psi at 70 Degrees F
Propylene (C3H6) is a colorless, flammable, liquified gas with a faintly sweet odor. It has high heat release in its primary and secondary flames. The heat release in the primary flame cone is similar to acetylene. The BTU capacity of the outer flame is superior to that of acetylene. Propylene combines the qualities of an acetylene flame with the secondary heating capacity of propane. The fuel gas burns hotter than propane; however, the cutting speed should be calculated on a case-by-case-basis before choosing this as the most economical choice as your fuel gas.
Interesting Info: A Propylene cylinder has a tank pressure of only 137 psi at 70 Degrees F
Argon/carbon dioxide blends are versatile mixtures for welding Carbon, Low-Alloy and some Stainless Steels.
Increasing the CO2 content will increase weld penetration and bead wetting characteristics. At higher current levels and CO2 content, increased spatter may result. Ar/CO2 blends can be used to join a wide range of material thickness while utilizing a variety of modes of metal transfer.
Ar/CO2 blends are used for all kinds of structural steel, farm implements and machinery. Lower levels of CO2 can be used for pulsed arc or spray arc welding, while higher levels > 20% are used for short arc welding and the shielding of some flux-cored wires.
ARGON 95% - 5% Co2
This blend is used for pulsed spray transfer and short-circuiting transfer on a variety of material thicknesses. A 5% mixture may be used for GMAW-P of Low Alloy Steels for out-of-position welding. The arc forces that develop give this mixture more tolerance to mill scale and a more controllable puddle than an argon-oxygen blend.
ARGON 90% - 10% Co2 **GREAT CHOICE FOR SPRAY-TRANSFERING MILD STEEL**
This blend performs similarly to the 5% blend, but with increased heat input providing a wider, more fluid weld puddle in either short-circuit or spray transfer.
ARGON 85% - 15% Co2
This blend has been used for a variety of applications on Carbon and Low-Alloy Steels. In the short-circuit mode of transfer, maximum productivity on thin gauge metals can be achieved with this blend. This is done by minimizing the excessive melt-through tendency of higher carbon dioxide mixes, while increasing deposition rates and travel speeds. As the carbon dioxide percentages are lowered from the 20% range (maximum spray arc levels), improvements in deposition efficiency occur due to decreasing spatter loss. This blend will support the spray arc mode of transfer.
ARGON 80% - 20% Co2
May be used for short circuiting or spray transfer welding of Carbon Steel.
ARGON 75% - 25% Co2 **GREAT CHOICE FOR SHORT-CIRCUITING MILD STEEL**
This blend is commonly used for GMAW with short-circuiting transfer on Low Carbon Steel. It was formulated to provide optimum droplet frequency on short-circuiting transfer using .035 and .045 diameter wire. This blend operates well in high current applications on heavy base metal. It promotes good arc stability, weld pool control, and weld bead appearance. This blend will not support the spray type mode of metal transfer.
Argon/oxygen blends are mostly widely used for conventional and pulsed spray transfer on clean (little or no scale or residual oil), plain Carbon and Stainless Steel. These blends, typically 1, 2 or 5% oxygen, provide good arc stability and very low levels of spatter and fume. Higher levels of oxygen will also increase puddle fluidity that may make out-of-position welding more difficult.
Generally used for welding heavy section Carbon Steel for farm equipment, military transports, ships and automotive assemblies. These blends are also used for spray arc welding of both ferritic and austenitic Stainless Steel components.
ARGON 99% - 1% OXYGEN
This blend is primarily used for spray transfer on Stainless Steels. One percent oxygen is usually sufficient to stabilize the arc and improve the droplet rate and bead appearance.
ARGON 98% - 2% OXYGEN **GREAT CHOICE FOR SPRAY-TRANSFERING STAINLESS STEEL**
This blend is used for spray arc welding of Carbon Steels, Low-Alloy Steels and Stainless Steels. It provides greater wetting action than the 1% oxygen mixture. Weld mechanical properties and corrosion resistance of welds made with 1% and 2% oxygen additions are similar. However, bead appearance will be darker and more oxidized for the 2% blends with stainless steels.
ARGON 95% - 5% OXYGEN
This blend provides a more fluid but controllable weld pool. It is the most commonly used argon-oxygen mixture for general Carbon Steel welding. The additional oxygen also permits higher travel speeds.
TRI-MIX - 90% Helium - 7.5% Argon - 2.5% Co2 **GREAT CHOICE FOR SHORT-CIRCUITING STAINLESS STEEL**
This tri-mix blend is widely used for short-circuiting transfer welding of Stainless Steel in all welding positions. The carbon dioxide content is kept low to minimize carbon absorption and assure good corrosion resistance, especially in multipass welds. The argon and carbon dioxide additions provide good arc stability and depth of fusion. The high helium content provides significant heat input to overcome the sluggish nature of the stainless steel weld pool.
TRI-MIX – 66% Argon – 26.5% Helium – 7.5% Co2
This tri-mix blend has been developed for spray and pulsed spray arc welding of both Carbon and Low-Alloy Steels. It can be used on all thicknesses in any position. This high-speed blend will produce higher quality welds over rust, oil, and mill scale than conventional two-part mixtures. It produces good mechanical properties and weld puddle control.
TRI-MIX – 66.1% Argon – 33% Helium – 0.9% Co2
This tri-mix blend is used for short arc, spray, and pulsed spray arc welding of Stainless Steel. It provides a higher welding speed, a broad weld with a flat crown and good color match, reduced porosity, and excellent alloy retention with good corrosion resistance.
Laser gases are produced to meet the stringent requirements of the laser processing industry. Available as pure gases or as pre-blended mixtures of helium, nitrogen, carbon dioxide, and occasionally, carbon monoxide, Laser gases are used to generate the laser beam in a wide variety of CO2 lasers. Carbon dioxide lasers must be protected from the problems created by moisture, hydrocarbons, and other contaminants which can be introduced through the gas supply system. These impurities can reduce laser power, create unstable operating characteristics, damage expensive optics, and cause costly downtime. With a properly designed delivery system, the use of Laser gases help assures optimum laser performance, maximum operating duty cycle, and minimum maintenance costs.