Metal Fabrication Resources by Blackstone Advanced Technologies

Mar 27, 2020 9:00:00 AM

Transferred vs. Non-Transferred Plasma Arc Welding

Plasma arc welding works by ionizing gases at high temperatures. Hot ionized gases are commonly referred to as plasma. Ionized gas that conducts electricity transfers an electric arc to the welding surface. The arc’s extreme heat welds two metal pieces together.

 

Plasma arc welding is almost similar to the gas tungsten arc process. An electric arc is between the workpiece and cross-sectional area is constricted leading to an increase in temperature.

 

What is Transferred Plasma Arc Welding?

 

This process uses a straight polarity DC current. The workpiece is connected to the positive terminal while the tungsten electrode to the negative terminal. The arc is maintained between the workpiece and the tungsten electrode. Heating of a co-axial gas maintains it in a plasma state.

 

Both the arc and plasma are transferred to the workpiece to increase the heating processes.

 

This process features a high-density plasma arc that conducts through the ionization of argon gas that’s passed through the electric arc. The transferred arc is throttled to achieve high temperatures, gaining a plasma column with temperatures between 8000- 18000 degrees Celsius.

 

Application of Transferred Plasma Arc Welding

 

This process is suitable for workpieces that are subject to wear and tear or corrosion. Transferred plasma arc welding is applied in the following processes;

  • forging matrix dies
  • plasticizing screw
  • making hydraulic cylinders
  • making moulds and accessories for the glass industry
  • forging industrial blades and knives
  • making automotive valves

Advantages of Plasma Arc Welding

 

Welders and engineers have a high preference for plasma arc welding. Some of the perks of plasma arc welding include;

 

High Levels of Structural Quality

 

Transferred plasma arc welding is different from other welding methods. It maintains metallurgical homogeneity, and the controlled penetration allows single-pass coating that translates to high-quality welding.

 

High Welding Speeds

 

Transferred arc welding can weld up to 500mm in a minute, more than cool wire TIG welding. If you want a fast welding process, this might be an ideal option for you.

 

High Energy Efficiency

 

High welding speeds limit thermal addition, thus saving much on energy. An average of 12KW of electric energy is capable of depositing six kos/h of metal. Additionally, this energy reduces the deformation of metal workpieces while maintaining the metallurgical structure.

 

Low Pollution

 

Compared to traditional welding methods, transferred arc welding produces fumes with low atmospheric pollution.

 

What is Non-Transferred Plasma Arc Welding?

 

In this process, the plasma arc torch has two electrodes, a rear and a front one. A direct current (DC) between the two electrodes create an iodized-gas plasma that’s constricted at the end of the torch.

 

The heat generated from non-transferred plasma arc welding is more dispersed than the transferred plasma arc. This makes the non-transferred arc welding process suitable for a wide range of applications. Current flows from the electrode inside the torch to the orifice-containing nozzle and back to the power supply.

 

Advantages of Non-Transferred Plasma Arc Welding

 

This process is suitable for large surface areas due to plasma spraying. Its main advantages include the following;

 

Precise Welding on Thin Metal Sheets

 

One of the benefits of this process is the production of precise welds. Unlike in the transferred plasma arc, products appear more clear-cut and robust.

 

Lower Energy Consumption

 

Compared to the transferred plasma arc, this method consumes relatively lower energy.

 

Application of Non-Transferred Plasma Arc Welding

 

The primary purpose of this process its plasma spraying. This is a thermal coating process whereby heat-softened particles that form a coating are applied onto a substrate. This reduces corrosion damage and gives materials a longer life.

 

To Sum Up,

 

Both the transferred and non-transferred plasma arc welding techniques are highly beneficial id executed well. Rather than hiring fly-by-night amateurs, consider AWS-certified welding experts and engineers. This way, your project will be a huge success.

 

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