Welding stainless steel is a skill that is hard to master. Even for the most experienced welders, it involves a lot of precision, patience, and practice.
Why welding of stainless steel is difficult? There are many reasons why you would choose to learn how to polish stainless steel.
Stainless steel is often used in high-end applications such as restaurant tables and bar tops, outdoor furniture, and track lighting.
If the need arises, you should know the fundamentals of welding stainless steel so you can confidently create custom pieces that will last a lifetime.
Why Welding Of Stainless Steel is Difficult?
Welding stainless steel is a difficult process because the material must be heated to a high temperature before it can be welded. This high temperature can cause the stainless steel to become brittle, which can lead to cracking or melting during the welding process.
In order to prevent this from happening, a filler metal must be used in conjunction with the stainless steel. The filler metal helps to strengthen the bond between the two metals and prevents cracking or melting as a result of heat.
It’s not enough! There’s alot of information to respond to the question of why stainless steel welding is difficult, so keep reading!
Which Issues can be Faced While Welding Stainless Steel?
The most important issue that can be faced while welding stainless steel is the formation of porosity. The formation of porosity is a major problem in the welded joints of stainless steel because it reduces the strength and toughness of the welded joints.
The second most important issue that can be faced while welding stainless steel is hydrogen-induced cracking (HIC). This occurs when hydrogen combines with chromium or nickel in the weld metal and forms brittle precipitates.
The third most important issue that can be faced while welding stainless steel is carbon depletion.
The fourth issue that can be faced while welding stainless steel is microstructure change. When filler metal is used to repair a defect in base metal, there may be an increase in hardness due to the formation of hard particles in the weld metal.
This increases hardness but decreases ductility, which makes it more difficult for these materials to undergo plastic deformation at elevated temperatures.
How do Various Welding Methods React to Stainless Steel Welding?
Stainless steel is a type of steel that is particularly resistant to corrosion and rust, making it a popular choice for many industrial applications. Although stainless steel can be welded, the process should be done carefully to avoid causing damage to the metal.
Welding methods are the most common ways of joining metals. The most popular welding methods include
- Gas tungsten arc welding (GTAW)
- Metal inert gas (MIG) welding
- Flux-cored arc welding (FCAW)
- Stick welding
Now, I will tell you how various types of stainless steel welds react to various welding methods in detail:
Gas Tungsten Arc Welding:
TIG or GTAW, a method of joining pieces of stainless steel together, is among the most popular methods for doing so. It uses an electrical current to heat up an electrode or tungsten rod, which creates a small pool of molten metal at its tip.
When this pool touches another piece of metal—like a piece of stainless steel—it causes them to fuse together permanently.
Metal Inert Gas Welding:
This method uses a special kind of wire that has been coated with a flux material (usually a mixture containing a binder resin and finely ground iron oxide powder), which helps prevent oxidation during welding operations.
The wire feeds through an automatic feeder while electricity passes through it; this creates an arc between the electrode tip and workpiece that melts both materials together into one solid object.
Flux-cored Arc Welding:
Flux-cored arc welding (FCAW) is the most commonly used method of stainless steel welding. The flux core that is used during this process creates a shielding gas, which protects the weld puddle from oxidation and corrosion.
Flux-cored arc welding can be used on a wide range of metals, including stainless steel, aluminum, and nickel alloys.
However, it does not work well with high melting point materials like tungsten carbide or molybdenum alloys because there is not enough heat produced to melt them before they become contaminated by impurities from the flux core.
So, I do not recommend this for high melting point materials because of contamination issues.
Stick Welding:
Stick Welding is another form of metal arc welding that is commonly used in stainless steel welding applications.
The two main types of stick electrodes are those made from solid wire and those made from hollow rods filled with fluxes and other additives such as copper powder or iron filings.
The solid wire electrodes contain no flux whatsoever, while the hollow rod electrodes do contain some amount of flux but not as much as FCAW electrodes do, so they’re less likely to contaminate your welds than FCAW electrodes would be if used improperly (which can lead to porosity problems).
Which One is Better?
All the methods are useful and advantageous for welding stainless steel in their own criteria. But, if you want clean and better welds, then I recommend going for TIG & MIG welding.
The reason is that these both methods are quite better than stick and flux core arc welding. Now it’s up to your welding project and preference.
Way to TIG Weld Stainless Steel
There are many ways to TIG weld stainless steel, and it all depends on the type of stainless steel you’re working with.
If you’re working with 304 stainless steel, then I suggest you use DCEN (direct current electrode negative) welding. This is because 304 stainless is non-magnetic and has a high resistance to corrosion.
If your welds are going to be exposed to salt water or other aggressive environments, this would be an excellent choice for your application.
If you’re working with 316L stainless steel, then you’ll want to use DCEP (direct current electrode positive).
This is because 316L has increased resistance to corrosion compared to 304, so if that’s important for your application, then this would be the best way for you to go about it.
For TIG welding stainless steel, you should have to consider the following considerations:
Make sure you have a good gas flow: You want your gas flow to be at least 40 cubic feet per hour, but anything less than that will give you problems with porosity in your weld.
Don’t set the heat too high: When you’re working with stainless steel, it’s easy to think that you can crank up the heat, but that’s not always the case! You need to keep it around 4-5 amps, or else it will burn through and make a mess of your welds.
Don’t use too much filler rod: When working with stainless steel, it’s important not to use too much filler rod because doing so can cause porosity in your welds and lead to rusting later on down the line (which is also bad).
Way to MIG Weld Stainless Steel
MIG welding stainless steel is a great way to create strong and durable welds. The process is similar to welding mild steel, but there are some important things that you’ll need to consider.
- Clean the metal with a wire brush to remove any rust and mill scale. If any rust is present, an etch primer must be used, or the weld will not stick to the bare metal.
- Apply the welding flux to the metal and tack weld it in place with MIG wire. Use as little welding current as possible so that you don’t overheat the metal and burn off the surface layer of paint or coating on top of it (this will leave a rough surface).
- Remove all excess flux with a rag before continuing welding on other parts of the project; if you don’t do this properly, it could cause an ugly weld seam later on due to trapped particles inside between layers of metal.
- Begin adding additional layers by drawing down your arc length until you have reached desired thickness for each layer (use an angle grinder with a wire brush attachment for cleaning up edges/corners where needed). You can use multiple passes at once if necessary without having to stop constantly (which would cause cooling issues).
How to Overcome Stainless Steel Weld Common Shortcomings?
Stainless steel is an amazing material. It has an extraordinary combination of high strength and good corrosion resistance, which makes it suitable for a wide range of applications.
However, the biggest shortcoming of stainless steel is its low toughness, especially at high temperatures. Although the majority of stainless steel alloys are quite tough, many welded parts in these alloys are less tough than the base metal.
So how can we overcome this common shortcoming? Here are some ways I will mention:
| No. | Ways to Overcome |
| 1 | Reduce the size of welds by using electrodes with higher current density or by using thicker filler metal. |
| 2 | Improve arc stability. |
| 3 | Use filler materials that have higher toughness than the base metal. |
| 4 | Use a more suitable weld joint design. |
| 5 | Choose a filler rod that has the same chemistry as the base metal so that you can avoid contamination during welding. |
| 6 | Use a filler rod with a lower melting point than the base metal’s melting point but make sure it is close enough so that it melts at least partially before reaching the heat zone of the joint. This will help ensure that there is some penetration into the base metal and reduce porosity in your weld joint. |
Advantages & Disadvantages of Welding Stainless Steel
Welding stainless steel is a process that can be used to join two pieces of metal together. The process of welding stainless steel has several advantages and disadvantages, some of which are not obvious to the casual observer.
| Advantages | Disadvantages |
| It is a strong type of welding because it makes use of an alloyed metal that is harder than most other metals. | Even though it does not require additional equipment, it does require special tools such as torches or welding guns so that you can complete the task correctly without damaging either piece of metal too much during use (which could cause them both to break apart). |
| It is less likely to break because the metal is resistant to corrosion, even if it has been damaged by scratches or dents. | For better welding results, you need to go for the two most common methods, such as TIG (Tungsten Inert Gas) welders, which are more expensive than other types of welding methods (such as MIG/MAG). |
| It does not require additional equipment such as rods or tungsten electrodes in order for it to be completed successfully. | While welding stainless steel, you need to require careful attention to temperature control welding so that the final product doesn’t become brittle from excess heat exposure during the welding process (which would make it less resistant to corrosion). |
Final Words!
So taking all this into account, it would appear that welding stainless steel is not such an easy thing to do. Having said that, if you have the correct procedures, it is possible to achieve a good quality stainless steel joint.
Although I provided a brief overview of why welding of stainless steel is difficult, the key to learning how to weld stainless steel is gaining an understanding of the process and using equipment that will allow for consistent and efficient results.
With a bit of practice, you’ll likely find that although welding stainless steel isn’t impossible, it does present some unique challenges during the welding process.
FAQs:
What are the challenges in welding stainless steel?
The biggest challenge with welding stainless steel can be determined by the metal’s chemistry. Stainless steels are susceptible to a wide variety of defects in the heat-affected zone (HAZ). Some very common defects include interstitial carbide formation, precipitate inclusions, decarburization, and grain growth. These can cause porosity and adverse mechanical properties.
What is best for welding stainless steel?
TIG is best when welding stainless steel. The high cost of the wire and shielding gas needed for TIG welding can be offset by its excellent control of heat input and superior finish.
Is stainless steel easily welded?
Stainless steel is often welded, but only when the weld is a small part of the overall design. Stainless steel’s low carbon content makes it susceptible to corrosion. As with all welding applications, proper surface preparation is critical to creating a strong and lasting weld.
Can a normal welder weld stainless steel?
Yes, a normal welder can weld stainless steel with the right procedure and technique. However, it requires the use of special TIG and MIG welding equipment and filler wire with a higher nickel content than is usually used for other types of welding. Remember that stainless steel is less conductive than mild steel, so don’t place too much heat on it in one place, or you’ll get hard spots.
