Welding Shielding Gases
During arc welding the weld area reaches high temperatures and all metals commonly used in fabrication will become contaminated by the oxygen, nitrogen and moisture in air. Welding Shielding Gases are used to shield the weld area from these contaminants.
GMAW (MIG), GTAW (TIG), PAW (Plasma Arc Welding) are gas shielded processes in which the shielding gas is provided from an outside source. Other processes like SMAW (Stick) or SAW (Submerged Arc) provide the shielding gases from the melting of flux.
Major Functions of shielding gases are to:
1. Protect the puddle from the atmosphere
2. Provide arc plasma
3. Provide oxygen for wetting (ferrous alloys)
4. Control type of heat transfer
5. Affect arc stability
Benefits of Individual Shielding Gases
- Oxygen - small amounts of Oxygen may be added to a GMAW shielding gas mixture to increase wetting and stability.
- Nitrogen - small amounts of NItrogen may be added to a GMAW shielding gas mixture to increases stability, improve weld penetration, and reduce distortion in the welded part
- Argon - Argon's inertness makes it a standard welding shielding gas and it promotes good arc characteristics and arc stability.
- Carbon Dioxide - Carbon Dioxide is an economical gas to use for the GMAW process with Carbon Steel and adds arc stability. The amount of fumes and spatter increases as the level of Carbon Dioxide increases.
- Helium - Like Argon Helium is completely Inert. Due to Helium's high thermal conductivity and ionization potential (amount of energy it takes to create an arc in the gas) it is ideal for applications where high heat input is required. Also, due to Helium's high heat input it is good for wetting.
- Hydrogen - Due to Hydrogen's high thermal conductivity and reactive nature small quantaties of Hydrogen are used in PAW (Plasma Arc Welding) and GTAW and GMAW of austenitic stainless steels.
Welding Shielding Gas Mixes
All these gases are mixed to utilize the benefits they each bring for many different applications.
Please contact us with questions.
Dry Ice
Dry ice is solidified Carbon Dioxide (CO2). Distinct from regular ice, which exists at temperatures of 32° F (0° C) and below, dry ice is extremely cold, -109° F (-79° C). Unlike water ice, dry ice does not melt. Instead, it sublimates (changes directly from solid to gas), releasing CO2. Carbon dioxide vapor is substantially heavier than air. In confined, poorly ventilated spaces it can displace air, causing asphyxiation. It is even possible for CO2 vapor to accumulate in low-lying areas, out-of-doors, under zero or very light wind conditions.
Dry Ice is sold by the pound and it typically available in quantities up to 100#. Please contact us to insure we will have the amount you desire. Also, we only typically store dry ice in Olean, so if you need it in Hornell be sure to call in advance. It is best to bring your own container that is not air tight and best if it is insulated.
How much Dry Ice do I need to keep my food frozen? See the Dry Ice Food Packing Chart (pdf)
Dry is most commonly used for its cold temperatures in freezing and cooling applications.
