MIG, also known as metal inert gas welding, is a popular welding method worldwide with applications in different sectors. MIG welding typically uses a wire rod that works as the electrode and is shielded by a gas flow or a mixture of gases.
Now, the use of the gases brings us to the question,
Is it possible to MIG weld with Nitrogen?
As a semi-inert gas, it’s entirely possible to use Nitrogen in different scenarios of MIG welding. However, the question remains to what degree you can use Nitrogen for MIG welding.
Nitrogen can bring excellent results in MIG welding if used as a purging gas or mixed with argon while shielding. But as Nitrogen is not fully inert like argon, you can’t totally replace it with other gases.
How does Nitrogen help in MIG welding
Now that we know Nitrogen can be used in MIG welding, let’s see exactly how it helps MIG welding.
- Better mechanical property: Whether used as purging or shielding gas, the presence of Nitrogen tends to increase the metal’s tensile strength. Especially, stainless steel can be greatly benefitted from the use of Nitrogen.
- Corrosion resistance: Nitrogen mixed with argon as shielding gas can increase the corrosion resistance of the metal. In the long run, you have more durable welding with a longer lifespan without any corrosion buildup.
- Stops oxidation: Oxidation is a common challenge in every welding project, and it just keeps increasing with temperature. But because of Nitrogen’s non-reactive nature, it plays an important role in stopping this oxidation from happening.
- Better arc stability: Arc stability is another crucial part of any welding project. With poor stability, the welding emits spatter, resulting in material loss, poor bead quality, and increased cleaning time. In this regard, Nitrogen can be a great help in providing better arc stability.
- Smoother metal penetration: Easy penetration is another precondition of good welding results. When mixed with other shielding gas like argon or helium, Nitrogen ensures a better heat transfer and makes the penetration process easier. This mixer of nitrogen and argon is good for heavy metal welding like railroad track welding.
What are the applications of Nitrogen in MIG welding?
Now that you know that Nitrogen can be used in MIG welding and how it helps, let’s clear out the specific applications nitrogen offers in MIG welding.
- As a shielding gas: This is the most common and talked about the application of Nitrogen in MIG welding. You already know, in MIG and TIG welding, a shielding gas is used to protect the weld from oxidation. This job of shielding is done flawlessly by done by the mixture of argon and Nitrogen.
- As purging gas: Another common use of purging gas, but this time nitrogen can work on its own. Argon and Nitrogen both can be used as purging gas, and both are non-reactive gases. But the production cost is so much lower for Nitrogen, making it an excellent choice as purging gas in MIG welding.
- As pre-heating gas: Pre-heating is an important part of the welding process that comes with a few benefits. For example, it reduces the cooling rate of the welding to prevent cracking and prevents micro structure buildup. This pre-heating is another widely used application of Nitrogen.
Is there any problem using Nitrogen for mig weld?
Normally, there is absolutely no concern if you use the right amount of Nitrogen in MIG welding for different applications. Nitrogen can be used as a sole gas for purging, so there is no issue at all. However, the problems still remain when you use Nitrogen for shielding purposes.
Though Nitrogen is pretty non-reactive, it’s not as noble as argon, and there is a slight reactivity in Nitrogen. So if you fail to balance the amount of argon and Nitrogen in the shielding gas mixture, it can affect the quality of the weld in a bad way.
What about the safety issue
Safety issues will always be there in any kind of welding job, but there is no particular issue that can arise by the use of Nitrogen. Typically, MIG welding can cause electrical and radiation-related hazards. Additionally, welding fumes and inert gas can be another major concern if you don’t use proper safety gear.
As a completely inert gas heavier than air, inhaling it can cause immediate unconsciousness. To avoid these safety issues, there are several things you can do. For example, checking out the equipment, using safety gears, and welding only by qualified personal can help avoid any unforeseeable safety hazard.
Nitrogen vs Argon: Which is the best purging gas for MIG welding?
In case you don’t know, purging is the method of eliminating oxygen, water vapor or any other gases from the place of joint. Most of the metals we work with, whether stainless steel or different alloy, are pretty sensitive to these things.
Now, this elimination is done by using fully or a partly inert gas like argon and Nitrogen. As they are chemically non-reactive, they work great removing oxygen, vapor or any other gases. Another benefit of these non-reactive gases is that they can prevent any explosion and corrosion buildup.
Now that you know what purging is and what gases are used, let’s see the differences between these gases and determine which one is a better choice for MIG welding.
As we are talking specifically about purging, the preference actually comes down to economics and availability. As argon is a noble gas, completely non-reactive and inert, of course, it’s a better choice than using Nitrogen.
On the other hand, Nitrogen might not be labelled as a noble gas, but it’s also non-reactive like argon. So, in terms of usage, both gases have similar characteristics and are really good choices for purging.
But the production cost makes all the difference here, and in this case, Nitrogen is a way better choice than argon. As Nitrogen’s main ingredient is raw air, it’s way cheaper to generate. So, in terms of cost-friendliness, nitrogen is the better purging gas in MIG welding.
Can you TIG weld using nitrogen gas?
TIG welding is quite similar to MIG welding, which also works with an electrode and shielding gases. Typically, TIG steel is used for more delicate projects where more precise welding is required. While welding, the shielding gas prevents oxidation from happening.
That brings us to the question of whether Nitrogen can be used for TIG welding. Again, the answer is similar to what I said for MIG welding. YES, you can use Nitrogen for TIG welding, but you have to combine it with argon and only be used when TIG welding duplex stainless steel.
Duplex stainless steel is basically a combination of austenitic and ferritic stainless steel, hence the name duplex. When these two types of stainless steel are combined, it creates a hybrid with extreme corrosion resistance and durability with a lower weight.
But to achieve the characteristics mentioned above, you have to make sure the weld doesn’t get exposed. Additionally, you have to maintain the distribution of austenitic and ferrite in duplex stainless.
Now, Nitrogen comes in strong specifically in this situation to protect the weld and balance the elements in duplex stainless steel. Not only does Nitrogen balance out these elements, but it also helps to increase the corrosion resistance and stabilize austenite.
Now a question may arise in your mind that,
Is It Possible To Do Mig Welding Without Using Any Gas
The answer is yes, you can. You can mig weld heavy thick metals as well as thin pipe without gas. For that you will need special type of welder that support gas less welding. You may check out the welders run without gas for that purpose.
You need to keep safety issues in mind while doing gasless weld.
That’s a wrap for today. I hope my article was helpful enough to teach the ins and outs of using Nitrogen in MIG welding. As you can see throughout the article, Nitrogen can be a great and economical choice in different applications of MIG welding.
If you know how to balance out the optimal quantity in mixing, Nitrogen can really boost the corrosion resistance and overall metal integrity of the welding.