Welding is the process of permanently joining two metals together through the application of heat. It has mainly industrial uses, but can also be utilized in everything from home, car and boat repairs to craft projects.
Welding techniques and materials differ slightly for every metal, including stainless steel.
Choosing the Correct Wire
There are many different types of stainless steel welding wire. Which one you choose depends on the application you will be using it for. Some wires are better suited to general-purpose applications, where only moderate corrosion conditions are experienced – such as chemical tanks and restaurant equipment.
Others are better for welding dissimilar materials – such as mild steel to stainless steel, or for barrier layers in stainless overlays.
The main difference between the various types of stainless steel welding wire is their composition. Some wires have a higher silicon content, for example, which improves wash and wetting behavior in the gas shielded welding process. Others have a controlled carbon content to reduce the possibility of the formation of inter-granular carbide precipitation.
Welding wire also differs in thickness, and which one you use again depends on the application. When welding thinner metals, use a smaller diameter wire. Thicker metal necessitates larger wire and a bigger machine.
It is very important to use the correct type of wire in relation to the base metal you are welding. Stainless steel welding wire should be used for stainless steel, aluminum wires for aluminum etc. if you are welding onto dirty or rusty steel, a wire containing more deoxidizers is needed.
Choosing the Correct Gas
The correct shielding gas is also essential. Carbon Dioxide (CO2) is good for steel, for example, but it is too hot for thinner metals. Argon is the only gas that should be used when welding aluminum.
There is no need to preheat the stainless steel if it is austenitic, but it should be preheated if it is martensitic or ferritic stainless steel, or if it is high in carbon, or very thick. The application of heat after welding is important to prevent internal stress and cracking from rapid cooling – particularly if you are joining two thick pieces of metal.
The Welding Warehouse, Inc. stocks a wide variety of welding materials in many differing grades and sizes. We also proudly stock PACWELD, our own, in-house brand of welding rods and wires. Ask us in store about its properties, uses and benefits, or visit us online at weldingwarehouseinc.com