Stainless Steel Welding: What is it, Benefits, & Methods

Stainless Steel Welding Methods

As a full-service fabrication company, aiming to provide the Saratoga Springs area with affordable, yet high-quality fabrication services, welding is something we know quite well. Although we mostly specialize in robotic arc welding—because of its consistent precision and maximum output—we are familiar with all types of welding. In today’s blog, we are going to direct our focus to some of the most common types of welding methods when working with stainless steel.

What Is Stainless Steel Welding?

Stainless steels are iron-based alloys with a minimum of 10.5% chromium in their composition. The inclusion of chromium is what causes the thin and dense chromium-oxide film to form on the surface that provides corrosion resistance. Other alloys are also included, with the end result being five different types of magnetic and non-magnetic stainless steels to select from, including:

Ferritic stainless steel
Duplex stainless steel
Austenitic stainless steel
Martensitic stainless steel
Precipitation-hardening stainless steel

In addition to chromium, these stainless steels can include different percentages of nickel, aluminum or both. Depending on the unique composition, they are categorized into 200, 300, 400 and 600-series stainless steel.

Is Stainless Steel Welding Difficult?

Across the industry, stainless steel is considered to possess good welding properties. It’s also very workable and weldable using various welding processes, including spot, resistance, electron-beam, arc, MIG or friction welding. For any of these methods, you must know the type of steel you’re working with and prepare your surface with a thorough cleaning.

Stainless steels have roughly 50% greater thermal expansion coefficients than carbon steels. The improved heat retention leads to less dissipation during welding, which means you’ll need to generate less heat to make the weld. They also have better electrical conductivity, so you can use less current during resistance welding processes.

Some stainless steels require extra attention during welding to get the best results. These include

Martensitic stainless steel: These steels benefit from preheating and post-weld heat treatment.
Ferritic stainless steel: Most ferritic stainless steels do best with minimal preheating (300 to 450 F).
Austenitic stainless steel: Make sure to use appropriate filler metals to avoid potential heat-cracking.

What’s the Best Welding Method for Stainless Steel?

Depending on the grade, thickness, and finish, the method by which stainless steel is welded varies. While there are a number of welding methods, there are three that are most commonly used. Below are these three types along with a brief description.

Gas Tungsten Arc Welding

Also known as tungsten inert gas welding (TIG), gas tungsten arc welding is the most common welding process. As the name indicates, a tungsten electrode is used to create a low-heat-input weld. More often than not, this process is used for thin materials like stainless steel as well as with other non-ferrous metals like aluminum, copper, magnesium. One common trick often employed when utilizing this method is to perform a single-sided weld, which creates an inert backing gas protection between interior and exterior welds, thereby bolstering up corrosion and oxidation resistance.

MIG Welding

MIG welding, or gas metal arc welding, is a semi-automatic welding process that makes use of argon-rich gas and a solid wire electrode. During this process, an electric arc forms between the wire electrode and the metals—or workpiece—causing the metals to melt and join. Because it offers a strong bond and it allows the welder to weld hard-to-reach spots, many prefer this process. Additionally, to better stabilize the arc and, therefore, improve the quality of the weld, welders will use a variety of gas mixtures—helium, oxygen, and carbon dioxide.

Spot Welding

Resistance or spot welding is one of the most popular and economic forms of welding. In the simplest terms, this is the process of joining two metal surfaces through heat created via resistance to electric current. This type of process is often used when welding sheet metal, wire mesh, and other thin materials with low melting points. The automobile manufacturing industry is perhaps the best and most common application of this type of welding. It is an essential part of shaping and forming automobile frames. Spot welding can also be completely automated using robotic welders, which yield reliably great results—check out some of the advantages of robotic welding.

Advantages of Stainless Steel Fabrication

Often rolled into sheets, plates, wires, and bars, stainless steel is used in cookware, cutlery, surgical instruments, construction materials, and a whole host of other applications. When it comes to industrial uses, stainless steel is often overlooked by engineers and designers because of its high initial costs. This, however, can be a rash decision. While this initial cost can be steep, stainless steel fabrication yields tremendous long-term value.

Below are some key advantages of stainless steel fabrication

Ease of fabrication — as metal fabricators, we see this as one of its top advantages. As long as you are using industry-leading technology—CNC machines, robotic welders, laser cutters, and more—stainless steel is quite easy to work with. It can be cut, bent, welded, and made to your specifications with relative ease.
Durable and resistant—not only is it a tough metal that is difficult to scratch and nick, but because of its chromium composition, it is also resistant to corrosion when exposed to wet environments. However, when it comes to acid exposure, certain types of stainless steel may suffer from corrosion. Additionally, stainless steel with high chromium and nickel-alloyed grades can be remarkably resistant to heat and fire.
Long-lasting—whether it’s a stainless steel appliance or construction material, stainless steel has proven to be a long-lasting material. On top of this, maintenance for stainless steel is relatively easy and effective. This is a detail that should not be left out of the decision-making process.
Recyclable—whether you are a consumer or a manufacturer, it is important to be cognizant of the impact your materials have on your community and planet. One of the great things about stainless steel is that it is 100 percent recyclable. In fact, over 50 percent of stainless steel comes from old scraps that have been melted and reused.

On top of all this, it is important to remember there are more than 60 grades of stainless steel, meaning you have a wide array of options to best accommodate your needs. When you couple this variety with a metal fabrication shop that has all the industry-leading technology to most efficiently service your needs, you can ensure

Not Sure What Type of Welding You Need?

If you are trying to choose which method of welding is best for your stainless steel project, don’t go it alone. There are a multitude of factors to take into account. If you need assistance, contact our fabrication shop. Our team can evaluate your project, materials, budget, and help you find the most affordable and effective solution. Contact us today!