Knowing the correct welding technique to apply in different situations is imperative, but you soon realize that that’s just the tip of the iceberg. A significant part of being an expert welder is identifying the suitable metal to achieve the most desirable and durable outcome.
Whether in it as a profession or for the thrill of art and watching the magnificence of creating new things, the bottom line is that you have to get the metals right.
Let’s quickly look into the characteristics of the metals and metal alloys that inform the decision to use one over the other.
- Melting point- At what temperature does the metal change its state from solid to liquid?
- Strength- What’s the metal’s threshold to endure force and pressure? Also, consider its breaking point.
- Ductility- How does it react when changing shape? Can it bend and stretch without breaking?
- Electrical conductivity- This determines the situations where the metals can be used
- Type of welding- There are different welding methods and the ideal metal type for each
- Weight- Is the metal the right weight for the intended project?
- Preparation time- This checks into dynamics like what goes into cleaning the metal before welding.
- Availability- Sometimes, you have to work with what’s available.
- Affordability- We have to factor in the cost of production.
Types of welding metals
Based on the considerations above, welders mostly use three types of metals:
- Stainless steel
The above isn’t a definitive list of the options available, but we selected the metals that accommodate a variety of welding techniques.
Steel is possibly the most used metal in welding. If you look around, you’ll see pipes, buildings, bridges, and anything else made from steel. How do you explain that?
Let’s first look into its properties. First, it has high tensile strength, meaning it endures too much stress, force, and pressure before breaking.
Steel’s main metal ingredient is iron, a 2% alloy, which mainly constitutes carbon. High carbon content implies stronger steel.
- Low carbon steel has less than 0.2% carbon. Its main advantage is that it’s malleable. This is the type of steel used to make the bodies of automobiles.
- Medium carbon steel has carbon ranging between 0.25% and 0.55%. Being less flexible makes it ideal for making axles. It’s also more durable than the former.
- High carbon steel is one whose carbon content lies between 0.55% to 2%. It’s the most durable of the three but also the most difficult to weld. Being heavy-duty steel, this type of steel is used to make hardy tools like harmers because they need to endure excessive force.
Steel’s versatile nature makes it applicable to most welding methods, including MIG, TIG, and stick welding.
We can also attribute its popularity to affordability. On the flip side, oxidation makes it susceptible to rust, so you want to avoid it where water will be involved. It’s also quite heavy compared to other metals.
I don’t advise using steel when welding anything that’s supposed to be lightweight.
2. Stainless Steel
Stainless steel is similar to plain steel, with the added advantage of being corrosion-resistant and highly hygienic. To achieve the non-corrosive property, it has 10%- 30% chromium. Nickel alloy is also an element of stainless steel.
Now that it doesn’t condone oxidation, stainless steel can be used in industries requiring immaculately clean conditions like food and medical and food production. Bacteria and other forms of microscopic pathogens can’t survive such cleanliness.
I always believe that welding using stainless steel is reserved for expert welders because of how much it expands when exposed to heat. Manipulating such a metal is never easy, so you have to be a guru in your craft to achieve the desired outcome.
You can use stainless steel in:
- TIG welding- Especially when using thin pipes and equally hoping for a pristine look.
- MIG welding- It takes less time.
- Stick welding- It’s the hardest to apply when using stainless steel because of the excessive splatter that can compromise the flawless finish.
Should you settle for this metal, you’ll have to cough out a few more bucks than using natural steel.
I can confidently declare aluminum the most common metal in all industries that require welding.
You’ll find aluminum in vehicles, airplanes, buildings, and household items, among many more. It has stellar properties like corrosion resistance, durability, and lightweight.
Aluminum alloys include copper, manganese, and zinc, all of which bear the above-mentioned properties.
You can use aluminum in TIG, MIG, and stick welding. For a seamless welding process, you need to clean the surfaces of any oxides. The thorough cleaning may have you incur extra costs but will prevent the welds from pooling, making them easier to handle.
Pro Tip: Preheat the aluminum before welding to make the process flawless.
The metals used in welding aren’t limited to the three discussed above.
Here is a list of others:
- Copper/ Copper Alloys- Here, you’ll use arc welding. Be keen on the intensity of the arc during welding because you want to complete the fusion with minimal heating around the base metal.
- It always comes on top as a viable welding metal because of properties like resistance to corrosion, heat and electrical conductivity, and durability.
- Cast Iron- It is a ferrous metal mostly preferred because of its low melting point, a highly required element in welding. Since it has high carbon content, you might want to go for oxyacetylene welding. Before welding, you’ll also have to thoroughly clean the surface to remove oil and grease.
- Magnesium Alloys- The alloys are lighter than aluminum and easy to cast. If you can weld aluminum perfectly, you shouldn’t have any problem with magnesium alloys now that they follow the same formats and use similar welding methods. You’ll need to be a TIG welder to ace it.
I can’t overemphasize the need to learn the characteristics of the metals and metal alloys you intend to use for welding. Most importantly, know their reaction when exposed to various degrees of heat. The metal of choice largely depends on the welding type and the project at hand.
Also, the less complicated it is, the better the outcome, especially when you’re still learning the ropes.