How to Weld Stainless Steel
Stainless steel is known for being long-lasting and durable. You can find it in nearly any household with growing popularity, but there are important considerations when welding this material. From preparation to after-weld care, the process requires a skilled professional willing to educate themselves on the best practices.
Learn more about how to weld stainless steel and the best techniques for doing so.
Can You Weld Stainless Steel?
Stainless steel is a very popular material used to manufacture various products, from kitchen appliances to auto bodies. It is 100% recyclable and a versatile type of metal that can work for many applications. In 2019, the global market size for stainless steel was more than $111 billion and it continues to grow today.
With proper care, you can weld stainless steel. While its heat and corrosion resistance makes stainless steel a hot commodity, it can be a tricky material to work with. Its thermal properties can pose an even greater challenge for welders.
Which Welding Method Is Best for Stainless Steel?
Welders should take extra caution when working with this material. A number of its characteristics make it difficult to perfect. For example, stainless steel retains heat, causing warping. Its surface is easy to mark and prone to scratches. A phenomenon called sugaring can cause discoloration that leads to rust and corrosion down the line. With all these factors to consider, it is important welders know how to handle stainless steel for the best end result.
The following methods are best for welding stainless steel:
Tungsten Inert Gas Welding
Tungsten inert gas (TIG) welding, short for gas tungsten arc welding, is considered the best way to weld stainless steel.
A professional will TIG weld stainless steel for critical joints or projects that need a lot of control. This technique is good for precise welds and sections that are especially thin because this process forms a low heat input. Welders often use argon gas to protect and cool the tungsten because it produces less smoke than alternative options and can prevent unsightly heat tint.
While it is one of the slowest methods, TIG welding has many benefits. It creates low electrode wear and is pore-free, resulting in a narrow fusion zone and less oxidation residue to clean up afterward.
Metal Inert Gas Welding
Metal inert gas (MIG) welding, also referred to as gas metal arc welding, is another common method for working with stainless steel. MIG techniques use electricity to melt and join metal together. Some people refer to this technique as the hot glue of welding.
When MIG welding stainless steel, a wire connects to a source of direct electricity that acts as an electrode passing through a welding gun. This method has multiple advantages, including:
- Efficiency: MIG is more efficient than conventional stick welding practices.
- Thickness: Can work on thicker pieces of stainless steel that require long weld lines.
- Cleanliness: This procedure produces less splatter and a cleaner weld.
Stick welding is a very common method with many benefits. It works by using electricity to melt a metal joint and electrode simultaneously so the welder can fuse the pieces together while filling the joint.
Welders can use it with various metal types, including stainless steel. However, this technique is not ideal for sheets that are especially thick or thin.
Some of the greatest advantages of stick welding are its low setup costs and minimal equipment requirements. A professional welder and the right electrode are all you need. It is a beginner-friendly method ideal for simple stainless steel projects.
Resistance welding uses force that converts to heat. The heat melts the metal sheets at each point, where they join with another sheet, resulting in a sturdy metal joint.
One of the benefits of using resistance welding with stainless steel is that it produces fewer fumes and is healthier for a working environment. It is more cost-effective than other methods and very efficient. Manufacturers can automate resistance welding, making it even more of an efficient choice.
Welding Process for Stainless Steel
Welding stainless steel can be challenging. The wrong move could lead to problems like warping or discoloration. Because of this, it is especially important to pick the right method for your project and the results you want.
When deciding which method is best, consider the following first:
- Costs: Each method is associated with different costs factoring in equipment and efficiency.
- Equipment: Before landing on the perfect method for your welding project, consider what equipment each method will require. This will also impact the costs.
- Quality: Some welding projects aim for aesthetically pleasing results, while others just want a sturdy joint. It is helpful to identify how pristine you want the welding work to look on the finished product before choosing your technique.
Once you’ve chosen your preferred method, you’ll need to select the right electrode for the job. Gather all necessary safety gear to keep yourself and anyone around protected from the dangers of welding.
When you have these things sorted, you can move through the three stages of the welding process.
Stainless steel is especially sensitive, and you can often see every imperfection from the welding process. Even small dust particles from carbon steel can leave behind unsightly blemishes. Because of this, it is best to prepare your work environment before getting down to business.
It can be helpful to clean surfaces and tools that will come in contact with the stain steel you’re working with as part of your preparation. Ensure your metal sheets align correctly and have no gapping. If you are working with thicker pieces, you may need to chamfer or bevel the edges to prepare for making the weld.
2. Making the Weld
The welding process differs slightly, depending on the method you choose. When making the weld, consider the following for the best results:
- Equipment: Check your equipment to ensure you have all the supplies you need and that it is ready for use before getting started. It can be helpful to keep extra items nearby in case you need to make a change while working.
- Lighting: Welding is an activity that requires ample lighting to boost visibility, so you can see every detail as you go.
- Ventilation: It is best to work in a well-ventilated area while welding. Working outdoors is a good idea, but if you can’t, be sure to have a functioning exhaust system and lots of fresh air.
- Safety: Beyond your stand safety gear and personal protective equipment, it is important to weld only when alert and mentally focused.
By following these guidelines, welders can produce the best work and stay safer while doing it.
Once you’re finished welding, it is important to clean the stainless steel. There are three methods for after-weld care:
- Mechanical weld cleaning
- Electrochemical weld cleaning
- Chemical weld cleaning
Stainless steel works best with electrochemical weld cleaning called electropolishing, which uses electricity and the oxidation from acidic electrolytes to remove stains and surface roughness while creating that shiny appearance that stainless steel is known for.
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