How to Weld Stainless Steel: MIG & TIG Process Covered

Last Updated on September 20, 2020 by Gary Hargrave

Stainless steel is undoubtedly one of the most widely used metals on the planet. We use it because of the irresistible benefits it offers. Not to mention, the most lucrative attribute of stainless steel is its corrosion resistance.

Since stainless steel generally isn’t extracted from nature and is being formed by combining two or more elements together, the million-dollar question comes into every beginner welders’ mind, can we weld stainless steel?

Well, let’s see…

Can We Weld Stainless Steel?

The answer to this question is, certainly! You see, almost every type of material, tools, and machinery we use in our day to day life have been at least partially or fully manufactured with stainless steel. And the process definitely contains small to a high number of welding finishes in order to strongly join its multiple parts. But it’s true that as stainless steel is a unique type of material, every welder must follow some critical instructions in order to efficiently perform the welding task.

how to weld stainless steel

Is it Difficult to Weld Stainless Steel?

Well, the answer is arguable. A welder needs to make himself aware of some general facts and factors before going to weld stainless steel. Now, this may include knowing all the different types of stainless steel that basically include a total of five types according to their microstructure.

Besides, he should also know how the metal preparation of stainless steel is different from that of other materials and what ranges of temperature and other pre-cautions a welder must follow while welding stainless steel.

Preparation of the Weld Metal

Now before beginning to weld any type of material, it is very crucial to clean it adequately in order to prevent any potential contamination. Besides, in the case of stainless steel, you need to be cautious about using any hammer or brush to clean that off.

You should definitely use a separate brush, hammer and clamp for using only over stainless steel because if the brush has been used previously over any other type of material such as carbon steel, there’s a high chance that some acute amount of that metal has been attached into that brush which may subsequently result in contamination and rust over your stainless steel.

How to Weld Stainless Steel?

There are basically five different types of welding processes for joining stainless steel among which two of them are the most common and frequently used for joining this popular metal. They are MIG welding and TIG welding. The best part is our guide will cover the Step-By-Step process for both of these welding techniques so that you can effectively weld stainless steel using either of these techniques.

What are the Required Gears?

Now the welding gears part can be split into two portions which basically consist of personal safety gears and welding tools. The personal safety gear part will cover all the essential apparel or tool a welder should necessarily wear prior to begin his welding work. The second part will detail all the essential equipment which are must or partially required in order to effectively and efficiently weld stainless steel using either MIG welding or TIG welding process.

Personal Safety Gears

  • Auto-Darkening Welding Helmet: The main objective of wearing this helmet is to protect your eyes from all sorts of sparks and other hot substances which may potentially jump onto your eyes during welding. Besides, if the helmet comes with an auto-darkening feature, you’ll have more vivid and transparent eyesight over the weld area & so will be able to weld more precisely over stainless steel.
  • Welding Jacket or Sleeves: Welding jackets or sleeves are generally designed to protect your arms and upper body from fire, sparks and other harmful substances. However, a welding jacket covers more of your body, but you can choose either of them according to your comfort and length of duty.
  • Welding Safety Glasses and Gloves: As safety always comes first, a welder must own welding glasses and gloves in order to protect his eyes and wrist area which basically stays in near proximity from the arc.
  • Kneepads and Welding Chaps: Kneepads are useful when you’re about to weld for long hours. You’ll feel comfort over your synovial area. On the other hand, welding chaps are a must since it protects your full lower body except for the feet area.
  • Respirator or Masks: Welding generates a high amount of toxic fumes which isn’t good for our body to inhale. Having a respirator or at least a mask will protect your body from these harmful gas and air.
  • Welding Boots: As the name suggests, welding boots will protect your feet area.

Welding Tools

  • A Welder: No matter what welding process you use, you’ll need a welder in order to power up your torch and produce the arc. You can use either a MIG welder or TIG welder for welding stainless steel depending upon your choice. Otherwise, there’re also some multipurpose welders which have the ability to perform multiple processes as per your requirement. Just make sure it comes with all the functionality and power capacity for welding your desired parts.
  • Electrodes: If you’re going to TIG weld stainless steel, you’ll require a standard non-consumable tungsten electrode. Besides, the tip of your electrode should be sharp enough in order to effectively perform the operation. A grinder can also do that.
  • Filler Metals: Choosing the appropriate type of filler metal for stainless steel is extremely critical like knowing how to precisely weld it. Because, stainless steel can be either chromium or chromium-nickel grade which also consists of three different groups naming ferritic, martensitic and austenitic.
    Now there is a particular AISI code for the base metal of all kinds of stainless steel. Depending upon your metals AISI code, you can find out the recommended base code of your filler metal which may also consist of one to three alternate types. You’re required to find the exact AISI in order to determine your appropriate filler metal.
  • Shielding Gas: For Shielding gas, we’ll basically use a ratio of 98:2 of argon and carbon dioxide mixture respectively. This is the gas that will duly protect our work from all sorts of atmospheric contamination. Besides, if you’re planning to MIG weld stainless steel, the best shielding gas you can use would be 2.5% of carbon dioxide, 7.5% argon with a 90% helium combination. Want to weld stainless steel without any shielding gas? I have an interesting article for you in that topic!
  • Angle Grinder: Angle grinder is another very essential tool that can be used to grind off your workpiece from all sorts of rust and paint which can result in post welding contamination. Besides, after you’re done with your welding, you can apply this grinder over the weld bead to give it a final finish and remove remaining slags.
  • Welding Clamps: Welding C-Clams are very crucial. You may need at least multiple of these to effortlessly perform your welding. They’ll be used to strongly hold down your workpieces with your welding table.
  • Magnets and Sheet Metal Gauge: Magnets are essential for performing welding at different angles with ease. Besides, Sheet Metal Gauge will be helpful for measuring the thickness of any part.
  • Metal Brush: As said earlier, you’ll need a metal brush for only applying over stainless steel.

Conditions Required For Your Workplace

As we know, welding generates a high amount of toxic gases and fumes. You should always work in a well-ventilated area. Besides, ensure grounding of all the major working tools especially the working table.

The Step-By-Step Process to Weld Stainless Steel (Both MIG & TIG Welding)

So now that we have all the pieces in place, let’s combine them and get the actual job done! To begin with:

  • Put On Your Safety Gears: That’s right; this is the number one most crucial thing every welder must do before beginning to weld. At first, you need to put on your welding jacket or at least a full sleeve shirt in order to protect your arms and upper body area. Secondly, put on your welding chaps, boots, and gloves.
  • Determine the Appropriate AISI Code for your Base Metal: Now that’s very important, as we know stainless steel is one of the most sensitive materials on the planet, you should definitely figure out the actual AISI code for the base metal you’re going to weld. This will allow you to get the most appropriate filler metal for using over your workpiece.
    As we said before, filler metals also come under a specific code and most of them again have some alternative types which can only be used interchangeability with that certain code/ type of filler metal.
  • Clean Your Workpiece Adequately: This is very important. As with every metal, a welder needs to clean it adequately from all sorts of rust, oil, grease and other contamination triggering substances prior to beginning your welding operation. You can use a metal brush to effectively do that.
  • Clamping: Now in this stage, we’ll secure our workpieces using C-clamps. To do this, we’ll first position all the workpieces on the correct angle and place. You can clamp them simply over your welding table. Just make sure they’ve been strongly clamped and there is no possibility of slip-ups, otherwise, your whole project could be ruined.

How To MIG Weld Stainless Steel:

The process of MIG welding stainless steel basically requires you to continuously feed a solid electrode wire inside the weld pool along with some shielding gas in order to protect the weld from all sorts of contamination. Besides, this process is quite simple and easy to do than TIG welding.

  • Setting Up Your Torch: Now firstly, you need to put the filler wire from the MIG welders reel to all the way up to the tip of your welding torch. Just make sure a 1/4 inch of that wire is visible after the end of your torch. Now activate the shielding gas and you’re ready to go.
  • Determine The Correct Angle: Position your torch above 30 degrees from the joint end and make sure the flame will straightly hit upon to that area.
  • Draw The Beads: Finally, turn on the power and slowly draw the weld bead all the way up to the end area. Don’t try to move too fast or slow. Besides, try to use the appropriate power, not too much or low otherwise it may result in spatters. In case of thinner parts, you can move the torch a bit faster than average because it melts quickly.

How To TIG Weld Stainless Steel:

This is basically a common and unique process for joining stainless steel. TIG welding stainless steel is performed by using a non-disposable tungsten electrode with a TIG welder for striking up the arc. This process also uses shielding gas against contamination but you can weld thinner metals more efficiently with it.

  • Configure Your Welder: At first, you’re required to appropriately configure your welder. As we are welding steel, we’ll choose the DC negative power also called DCEN. You can also use the DC positive or DCEP, but it’s used for Stick welding steels only. However, AC is used over aluminum.
  • Setting Up Your Torch: Now put your tungsten electrode inside the torch. You gotta make sure that the tip of the electrode has been sharpened enough and a 1/4 inch visible part stays outside the torch which can be referred to as the nozzle.
  • Determine The Correct Angle: Unlike MIG welding, this time we’ll hold the torch at a 75-degree angle above the joint edge. But make sure, you don’t touch the electrode to the joint otherwise you may need to grind the tip-off that again.
  • Draw Your Weld Beads: Now get your feet on the foot pedal of the TIG welder and draw the lines. The process is similar to MIG welding except that you need to continuously feed the filler metal after every few seconds.
  • You’re finished! : Finally, wait for the metal to cool down and you’re ready to go.

Measures to Ensure Safety

Always put a fire extinguisher near your working area because accidents can anytime happen and this will ensure the overall safety. Besides, as soon as you are done with your work, wind up everything and put them in a safe and clean place for the next use.

Final Words

Knowing how to weld stainless steel can give you a tremendous head start in your welding career just because the material is very sensitive and also one of the widely used. We believe this guide has provided you with all the instructions on how to weld stainless steel.

Thanks for reading the whole post. Stay along with us for our upcoming articles

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