What is Depth of Fusion in Welding?

The depth of fusion is the distance that fusion extends into the base metal or previous pass from the surface melted during welding. It is important to ensure that adequate depth of fusion is achieved in order to create a strong and durable weld joint.

What are the factors that affect the depth of fusion?

There are various factors that can affect the depth of fusion, such as:

  • the welding process,
  • electrode type,
  • and welding parameters.

In general, deeper fusion will result in a stronger weld joint.

  • One way to ensure adequate depth of fusion is to use an electrode with a deep penetration capability.
  • Another option is to increase the welding current or travel speed.
  • If necessary, multiple passes may be used to achieve the desired depth of fusion.

Depth of fusion is an important consideration in any welding application.

How do you measure weld depth?

Depth of fusion can be measured using a variety of methods, including radiography, ultrasonic testing, and macroetching.

  • Radiography is the most common method used to measure the depth of fusion.
  • Ultrasonic testing can also be used to measure the depth of fusion. This technique uses sound waves to identify imperfections in the weld joint.
  • Macroetching is another option for measuring the depth of fusion. In this process, the weld joint is etched with an acidic solution and examined under a microscope for evidence of penetration.

What is the difference between fusion and nonfusion welding?

Fusion welding is a welding process that uses heat to melt the base metal and create a weld joint. The molten metal is then cooled to create a strong and durable bond. Non-fusion welding, on the other hand, does not use heat to melt the base metal. Instead, it relies on pressure or friction to create a bond between the two pieces of metal.

While both methods can be used to create strong and durable weld joints, fusion welding is generally preferred for its ability to produce deeper and wider welds. Non-fusion welding is typically used for thinner materials or in applications where heat-sensitive materials are being joined.

What causes low fusion in welding?

There are several factors that can cause low fusion in welding, including:

  • using an electrode with a small diameter,
  • welding at a high travel speed,
  • or using a low welding current.

Other factors that can contribute to low fusion include poor joint design and improper weld preparation. Low fusion can also be caused by contamination of the base metal or welding consumables.

Good to know:

1) Fusion face welding

It is the process of joining two materials by melting them together and allowing them to cool to create a single piece. This can be done with metals, plastics, and other materials.

2) The leg of a fillet weld

It is the slanted side of the weld that joins two plates at an angle. It can be used to calculate the throat thickness, which is the shortest distance between the root and face of the weld.

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