Quality Control during the Welding Process: Identifying a Poorly done Weld

Most of the metal-based structures that you see on a daily basis were likely produced by welding. Welding is the most efficient method available for joining sheets of metal in a durable and permanent fashion. Therefore, it is important for any welding process to be done in high quality to ensure the integrity of the final structure.

There are several ways you can ensure that a welding job you requested for was done in the right way. Multiple testing methods are available to ensure the quality of a weld, and these methods are primarily based on a functionality test of the final structure.

Checking the material distribution

One of the most common ways of welding quality control is to check how the materials were joined. Welding primarily functions on the basis of a weld pool, where two materials are brought to boiling temperature and joined via their common weld pool.

A high quality weld will typically have the two materials evenly distributed across the welded surface. If the material distribution is uneven, the welded surface may become unstable and unable to withstand stress along certain points.

Analysing the amount of waste produced

A high quality weld also needs to free of waste. The most common culprit is slag, which tends to appear after the welding surface cools. Slag and other residues from welding can pollute the weld pool and introduce materials that may interfere with the quality of the welded surface.

These residues may also cause corrosion and interfere with the overall appearance of the surface. A high quality weld should always appear clean and polished.

Checking the strength

Any welding process should result in a firmly joined surface. Welded surfaces should be put on stress tests that are more vigorous than the regular environment in which the structure will be subjected to. Welding strength can also be tested using tools such as electrode ratings or filler metals.

Quality Control via the Welding process used

If there was a specific welding method that was used, you can determine the quality of the weld by watching for certain key elements.

MIG Welding

A high quality MIG weld should be uniform in appearance, and have no discoloration on the joined metals. The weld should also be of an appropriate thickness to ensure sturdiness.

Poor TIG Welding

As a stainless steel welding process, a high quality TIG weld should have no filler metal used on the joined surface, no burnout of the involved metal, and no tungsten inclusion. This will ensure that the welded metals used maintain their durability and functionality in the final product.

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