Step to Step (Gas, Amps, Alloys, Polarity, Tips, etc) for How to TIG Weld Steel

TIG welding, also known as Tungsten Inert Gas welding, is a highly valuable method for joining metals, especially steel. This technique involves heating the metals using an arc created between the tungsten electrode and the base metal. To facilitate the process, a filler metal may be used in conjunction with a shielding gas. The key variables in TIG welding are the welding current, arc voltage, shielding gas composition, and travel speed. Properly controlling these variables is crucial to achieving high-quality welds in this process.


How TIG Welding on Steel Works?

Tungsten inert gas (TIG) welding stands as perhaps the most versatile welding method, offering the capability to weld a myriad of metal types that surpass other welding techniques. TIG welding finds wide applications in joining aluminum, steel, brass, copper, bronze, gold, nickel alloy, stainless steel, and more. To acquire proficiency in TIG welding, firstly, you must configure the welding machine along with its associated components, such as the torch and gas supply, while also ensuring you have a suitable filler rod on hand for the specific metal you intend to weld.

What Parameters Are Important?

The achievement of a fruitful welding operation relies on a skillful blend of parameter settings and choices. Various knowledge-based factors significantly influence the selection of parameters and the setup of equipment. Among these crucial factors are the base material, material thickness, joint type, and welding position.

How to Create Great Beads on Steel

The fundamental process of laying a bead is deceptively simple. Your goal is to create a minute zig-zag pattern using the tip of the rod, while employing small concentric circles along the seam’s path. To start, it’s advisable to lay beads that are just one or two inches long. This precaution is essential as there’s a potential risk of excessive heating around the seam, leading to compromise or warping. To mitigate this, it’s best to perform a small weld in one spot before moving on to another.

Suggested Electrodes

When working with aluminum materials, it is essential to opt for a tungsten electrode. However, one must exercise caution as there are other types of tungsten electrodes available, including the thoriated variant, which poses inherent risks. Currently, the process of preparing an electrode involves ensuring that its tip is shaped in a circular manner; otherwise, it needs to be ground before use. It is highly recommended to use a ball-shaped tip for welding with AC power and a pointed tip for welding with DC power.

What Polarity Should I Use When I TIG Weld on Steel?

Polarity stands as one of the most crucial factors influencing the quality of welded joints. If the polarity is incorrectly chosen, you may experience inadequate penetration, increased spattering, and loss of control over the welding arc. There are three types of polarity available:

Straight Polarity (DCEN) – This polarity is vital in TIG welding on steel, as selecting the appropriate polarity greatly impacts the weld’s quality and strength.

Direct Current Straight Polarity

This occurs when the electrode is negatively charged, and the plates are positively charged. As a result, electrons flow from the electrode tip to the base plates.

Direct Current Reverse Polarity

This phenomenon occurs when the electrode is positively charged, and the plates are negatively charged. Consequently, the flow of electrons reverses direction, moving from the base plates to the electrode.

Alternating Current Polarity

When the power source provides an AC current, both direct and reverse polarity will alternate in every cycle. During half of a cycle, the electrode will be negative, making the base plates positive. In the other half of the cycle, the base plates will be negative, and the electrode will be positive. The number of cycles that occur within a few seconds depends on the frequency of the power supply.

What Pulse Can I Use on Steel?

Pulse TIG welding finds frequent application in joining thin sections of stainless steel and non-ferrous metals. However, its utility extends beyond these materials, as it is also employed for welding copper alloys, magnesium, and aluminum, among others.

Amperage of TIG Welding on Steel

To initiate TIG welding, specialized machines are designed to deliver a consistent amperage at all times. The machine settings are configured in terms of amperage, which remains relatively constant during the welding process. Any changes in voltage are dependent on the length of the welding arc, as voltage is measured through the arc. When the arc length increases, the voltage also rises, and vice versa when the arc is shortened. The power supply ensures a steady amperage setting. For welding ¼ inch steel in a single pass, approximately 180 amps are required. Alternatively, for thicker materials, a series of thin passes can be employed with less amperage needed per pass. However, multiple passes may result in longer welding times.

When TIG welding on highly thin sheet metal, it may be necessary to switch to direct current electrode positive. This would direct more heat onto the tungsten electrode, preventing the arc from burning through the sheet metal. When using a direct current electrode, welding with a low amperage setting is advised to prevent the tungsten from burning up as well. Additionally, in some cases, the machine may need to be set to direct current electrode to shape the tungsten into a ball end. This process allows the direct current electrode to quickly melt the tungsten, enabling the creation of ball-shaped tungsten ends, commonly used in TIG welding.

TIG Welding on Steel Gas Selection

Gas serves a diverse range of purposes in the welding process, each with its unique benefits. Primarily, it functions to shield the welding arc from contaminants like dust, air, and other gases. This protective gas environment also helps maintain clean and tidy welds on the base layer, ensuring a smooth welding process and effectively heating the metal. Additionally, blanketing gases can be employed to safeguard the metal after the welding process, providing further protection and preserving the integrity of the welded joint. Here are the lists of gases commonly used for each welding type that described below:

• Reactive and inert gases

• Purging gas

• Shielding gas

• Blanketing gas

• Heating gas

Gases play a crucial role in every welder’s job. Certain gases find extensive use in various applications, such as pure argon for numerous TIG welding steel projects, and a combination of CO2 and argon for several MIG welding jobs. When it comes to TIG welding on steel, the gas of choice for most welders is Argon.

Is Helium a Good Option?

Helium serves as an excellent choice for achieving successful TIG welding of carbon steel material. This non-reactive welding process results in clean and precise welds. Compared to argon, helium is hotter and more efficient in transmitting the arc’s heat, making it an advantageous option for specific welding applications.

Is co2 a Good Option?

You are correct. CO2 is not used for TIG welding due to its oxygen content, which can lead to oxidation and result in poor weld quality. Therefore, carbon dioxide should not be used in TIG welding.

Can I TIG Weld With 75% Argon & 25% co2 on Steel?

You are absolutely right. CO2 is an active gas and can cause oxidation when present around the tungsten electrode in a TIG welder. For TIG welding, it is essential to use pure argon to protect the electrode. Therefore, using an Argon-CO2 mix on steel during TIG welding is not recommended and considered a bad idea.

How to TIG Weld Mild Steel?

Mild steel is a type of steel alloy that contains a lower percentage of carbon, typically 0.3 percent or less, which earns it the name “low carbon steel.” This material is widely used in fabrication due to its cost-effectiveness compared to other alloys and its ease of welding. Tungsten inert gas (TIG) welding is a commonly used method for welding mild steel, resulting in clean and precise welds.

Mild steel offers numerous advantages, including its weldability and the ability to be easily shaped and molded. These attributes make it a popular choice for many welders. However, it is important to select the appropriate filler metal for your specific application, as the features of mild steel may vary depending on the material type. Generally, mild steels have less strength when compared to low-alloy steels.

The ease of weldability and absence of additional elements make mild steel an affordable option for constructing durable structures. It serves as an excellent starting material for new welders due to its straightforward welding characteristics. However, TIG welding requires more finesse and concentration compared to processes like oxy-acetylene torch welding or metal inert gas welding. It is essential to ensure that both the workpieces and the welding rod are clean before welding mild steel, as any contaminants can adversely affect the weld quality.

How to TIG Weld Cast Iron/Steel?

Welding cast iron can be challenging, but it is certainly feasible. In most cases, welding on cast iron involves repairing existing castings rather than joining cast iron to other components. Understanding the intricacies of welding cast iron is crucial for successful repairs. Typically, cast iron contains a carbon content of 2% to 4%, which is significantly higher than that found in many steels, making it more difficult to weld.When it comes to welding cast iron steel, below are four simple steps must be taken out before obtaining started:

  • Predict an alloy
  • Clean the casting carefully
  • Choose the pre-heat temperature
  • Choose a suitable welding procedure

Before commencing the welding process, it is essential to select the appropriate polarity based on factors such as the filler material, specific requirements, base material, and electrode type. Choosing the right polarity ensures optimal welding performance and results.However, the parameters generally affected by tig polarity are including:

  • Filler deposition
  • Base plate cleaning
  • Weld penetration
  • Weld bead look
  • Reinforcement
  • Heat affected zone
  • TIG Welding On Stainless Steel

The welding process for stainless steel varies depending on its thickness. It is crucial to consider the desired characteristics of the finished product before proceeding with the weld. Various welding procedures exist for stainless steel and are commonly employed by welders. Hence, it is essential to select the most suitable method based on the specific qualities you are seeking in the welded joint. Below are some of the common methods for welding stainless steel that includes:

  • Tig welding or gas tungsten arc
  • Mig welding or gas metal AC welding
  • Resistance or spot welding

When it comes to TIG welding on stainless steel, there are several recommendations to consider. Similar to TIG welding on regular steel, achieving a proper balance between travel speed and amperage is essential. Ideally, you should position the electrode close to the puddle and maintain a high travel speed. This approach helps minimize discoloration and reduces the size of the heat-affected zone. By maintaining a high travel speed, even if using a higher number of amps, excessive heat transfer to the welding area can be avoided. If you are unsure about your ability to weld quickly enough, it is advisable to lower the amperage to ensure better control over the welding process.

I always recommend conducting test welds before proceeding with the desired connection, as the size of the weld plays a crucial role. It is advisable to begin with approximately 100 amps and make necessary adjustments based on the factors discussed in the previous paragraph. By altering these factors, such as travel speed and amperage, you can calibrate the welding parameters to achieve the desired weld quality and characteristics.

How to TIG Weld Hardened Steel?

Another crucial consideration when performing TIG welding on hardened steel is to ensure that the electrode is positioned slightly away from the weld metal to prevent splashing, as molten metal could potentially jump from the area.

To initiate the welding process, apply some pressure on the pedal to quickly heat the weld metal. This will create a weld pool in the designated area, allowing the metal to become molten for proper welding. However, be cautious not to apply excessive heat to the weld metal, as it may lead to shrinkage or bending after cooling. It is advisable to practice beforehand to gain proficiency before starting the actual welding.

Once the weld pool is formed, feed the welding rod into the pool while keeping the electrode close to it. This technique is particularly suitable for welding aluminum materials. In case the weld metal needs melting, gently apply some pressure on the welding paddle; conversely, if it appears to be getting burnt, ease off on the pressure.

Before welding, clamp the material pieces together, and mark both sides of the welding area using suitable welding temperature crayons. These marks will melt at different temperatures, helping to prevent overheating the material. Preheat the welding area with a propane blowtorch for a few minutes to maintain its crystalline structure. Proceed to weld the hardened steel together along the metal seam using the welding machine, and monitor the metal’s temperature before making multiple passes of the welding torch to create a deep welding preparation.

How to TIG Weld Rusty Steel

TIG welding is the preferred choice of welding professionals to avoid the common problem of rust formation on the weld site. Let’s delve into how to use a TIG welder for welding rusty steel. TIG welding is a modern arc welding process that utilizes a non-consumable tungsten electrode to fill and fuse metals. Compared to other welding methods, TIG welding offers numerous advantages. This method allows you to join metals by heating them to the necessary temperature to create a strong bond, making it particularly suitable for welding thinner metals.

How to TIG Weld Corten Steel

Corten steel, also known as weathering steel, is a popular choice due to its exceptional durability compared to many other types of steel. This material exhibits high resistance to corrosion, allowing it to endure for many years. TIG-welded corten steel finds extensive use in shipping containers, bridges, tanks, and various other products. Corten steel utilizes the natural weathering process to develop a protective outer layer that resists atmospheric corrosion and degradation. Both ASTM A242 and ASTM A588 CorTen steel materials can be TIG-welded according to specific requirements. The aesthetically unique characteristics of this material make it a commonly used option in the transportation industry, serving as a more affordable alternative to stainless steel, often used in the railway sector.

What’s the TIG Weldability of Zinc-Coated Steel?

Welding on zinc-coated steel is possible, but it should not be done in a confined area. To achieve the best results, it is recommended to use corrosion-resistant weld metal and consider using a bronze deposit, such as a stainless steel electrode or a copper-zinc alloy, to improve the welding process. One major challenge associated with zinc-coated materials is that zinc has a boiling point close to its melting point. During arc welding, the zinc may vaporize because the arc generates higher temperatures than flame-based processes. It is crucial to take specific precautions when welding zinc-coated steel to avoid any issues. Remember that the boiling point of zinc is below the melting point of steel.

What Defects and Problems Occur on Steel

Indeed, TIG welding can lead to various problems and defects on the steel. Some common issues include porosity, lack of fusion, cracking, distortion, and improper bead shape, among others. These problems may arise due to factors such as improper shielding gas, incorrect welding parameters, inadequate preparation of the base metal, and insufficient skill or experience of the welder. It is essential for welders to be well-trained and knowledgeable in order to minimize these issues and produce high-quality TIG welds on steel.However, some of these problems are as follows.

  • Poor gas coverage leads to stain
  • Welding aluminum by adjusting the balance or in the wrong polarity
  • Weld graininess
  • Lack of fusion in the root
  • Craters
  • Dirty base and filler metal
  • Poor color on stainless
  • Sugaring on stainless steel
  • Too much amperage on aluminum
  • Proper arc length control

How to Avoid Bubbles

If bubbles form during the TIG welding process, it indicates a leak, and you must replace the defective components to ensure proper welding. To avoid the formation of bubbles in your TIG weld, it is essential to be mindful of several critical factors. For instance, closely monitor the voltage and arc length during the welding process. Proper control of these parameters can help prevent the occurrence of bubbles and ensure a successful weld. Additionally, ensuring the integrity of the welding equipment and using high-quality components is crucial in achieving bubble-free TIG welds.

Is Porosity a Big Issue?

Porosity in TIG welding occurs when gas or contaminants are absorbed into the weld puddle. This leads to a weak and bubble-filled weld that fails to meet the required standards and compromises the integrity of the project, ultimately leading to potential failure. If porosity is detected in your weld, it is crucial to redo the welding to ensure a sound and reliable joint.

To prevent porosity in TIG welding, you can take the following measures:

  • Keep the material surface clean
  • Check the gas flow
  • Take a look at your equipment
  • Check your workspace conditions
  • Tips for Tig Welding on Steel

TIG welding, among the various options like oxyacetylene, stick, and MIG, stands as one of the most versatile welding methods available. It can be used to weld materials such as titanium, copper, and even dissimilar metals, making it valuable for intricate welds on round or curved surfaces.

In TIG welding, an arc of electricity jumps from the non-consumable tungsten electrode to the metal surfaces being welded, typically steel or aluminum. This process is known for its precision and capability to produce high-quality welds. While it may be slower compared to other methods, the results are top-notch.

TIG welding is commonly used for welding metals beyond common steel, tackling challenging weld joints, and performing small, precise welds. It is a preferred choice when welding requires utmost accuracy and control.

Also known as gas tungsten arc welding, TIG welding utilizes a non-consumable tungsten electrode to provide ample current for the welding job. The use of filler metal is optional, depending on whether the welding is autogenous or not. Moreover, a shielding gas is employed in TIG welding to protect the welding process from environmental contamination and ensure a clean weld.
TIG welding, among the various options like oxyacetylene, stick, and MIG, stands as one of the most versatile welding methods available. It can be used to weld materials such as titanium, copper, and even dissimilar metals, making it valuable for intricate welds on round or curved surfaces.

In TIG welding, an arc of electricity jumps from the non-consumable tungsten electrode to the metal surfaces being welded, typically steel or aluminum. This process is known for its precision and capability to produce high-quality welds. While it may be slower compared to other methods, the results are top-notch.

TIG welding is commonly used for welding metals beyond common steel, tackling challenging weld joints, and performing small, precise welds. It is a preferred choice when welding requires utmost accuracy and control.

Also known as gas tungsten arc welding, TIG welding utilizes a non-consumable tungsten electrode to provide ample current for the welding job. The use of filler metal is optional, depending on whether the welding is autogenous or not. Moreover, a shielding gas is employed in TIG welding to protect the welding process from environmental contamination and ensure a clean weld.

Tig vs MIG Welding on Steel

Currently, TIG welding is widely used due to its ease and straightforward application. Although it is slower than other processes like MIG welding and shielded metal arc welding, TIG welding offers welders greater flexibility and control over the entire welding process, resulting in long-lasting and durable welds.

TIG welding is highly versatile, capable of welding a wide range of materials. Additionally, it provides excellent resistance against corrosion, making it a favorable choice for such applications.

TIG and MIG welding on steel exhibit several differences, with the main distinction being the way the arc is utilized. In MIG welding, a feed wire continuously moves through the gun, creating the spark necessary to melt the material and form the weld. On the other hand, in TIG welding, long rods are used to directly fuse two metals together. MIG welding is more efficient for thicker metals and faster welding, while TIG welding is ideal for thinner materials. TIG welding is well-suited for stainless steel, mild steel, and aluminum.

How to Tig Weld a Steel Pipe

Currently, achieving a perfect finishing after welding requires the use of weld metal. To clean the metal surface, a wire brush, preferably made of stainless steel or aluminum, can be utilized. Clamping helps maintain the position of the weld metal during welding, and applying anti-spatter spray prevents welding drips, ensuring a smooth surface.

Safety preparation is of utmost importance when TIG welding steel pipes or any other material. Proper safety measures, such as wearing dark helmets, welding gloves, toe shoes, and long-sleeved shirts or jackets, are essential to prevent accidents like eye damage or skin burns. Cleaning the welding helmet before starting the task enhances visibility, and additional lighting can be used to improve the process.

For TIG welding on steel square tubing, consider these tips: clean the mill scale, ensure squareness of the materials, and use at least three tack welds on each joint. When welding the outside corner, start from the inside and work your way outside to minimize distortion. Sometimes, using a lay wire technique can make the welding process easier.

What’s the Heat Input of TIG Welding on Steel

The keyhole TIG welding process requires high heat input due to its high amperage. This combination of high currents and high-speed welding allows for deep penetration, while still maintaining modest heat input within the acceptable range. For instance, when TIG welding on 304 stainless steel with a 10mm thickness, the approximate heat input is typically 1.4 kJ/mm gross.

Heat input is a critical factor for successful TIG welding on steel. Consulting with qualified welders can help determine the appropriate heat input for your specific welding project. To calculate the heat input, you can measure the voltage and amperage in your welding machine using analog or digital meters, and then divide it by the overall travel speed. The formula is (60 x Amps x volts) / (1000 x travel speed in in/min) = KJ/in. Travel speed is calculated by dividing the length of the weld by the time taken to weld it. Faster travel speed reduces heat input. Lowering the amperage and voltage can also help achieve a lower heat input.


  1. TIG Welding and Back Purging on Steel

Back purging is a crucial practice in TIG welding to protect the root run of the weld from oxidation on the non-weld side. By using the same inert gas to protect the weld pool, the root run remains shielded. Weld designers can opt for root purging when access to the root is available. To remove the root, grinding can be used, followed by rewelding from the root side.

  1. Should I TIG Weld on Steel Chassis?

Seam welding on a steel chassis is feasible and distortion is not a major concern for thick folded panels. Properly using the equipment and techniques can make the seam welding process quick and easy. Follow the guidelines accurately to complete the chassis welding as required. If you have any doubts, consult specialists in the field before starting the welding.

  1. TIG Welding on Steel Lap Joint

To successfully TIG weld a lap joint, follow step-by-step instructions and be adept at manipulating and reading the weld puddle before adding filler wire. You can practice with autogenous welds and eventually add filler as needed.

  1. TIG Welding on Steel With Brass Filler Rod

TIG welding brass can be complex due to the zinc content with a low melting point. To weld brass, use an inverter with appropriate pulse settings and ensure enough heat input to create a puddle. Pulse the pedal quickly while adding the rod and control the arc to cover the entire puddle.

  1. TIG Welding on Steel With Silicon Bronze

TIG welding with silicone bronze is considered tig brazing, as the base metal being joined has a higher melting point than the silicon bronze filler rod. Mixing excess steel into the silicone bronze can lead to cracking and a brittle weld or braze. Be cautious when using this combination.