Backing Weld Pass
The backing of the weld joint is a prepared surface on the root side, created by back gouging and any additional treatments. It is intended to eliminate flaws and increase the integrity of the joint.
Physical-Chemical Mechanism of Action
The backing of the weld joint is created by back gouging surface materials. This removes dirt, corrosion layers, and uneven surfaces that could lead to poor weld results.
Metallurgical Relevance & Welding Risks
A poor backing can lead to defects like porosity, cracks, or inadequate stress distribution. This compromises the strength and reliability of the weld joint.
Shop Practice & Instructions
Before creating the backing, the root side must be thoroughly cleaned. This can be done with chemical cleaners or mechanical methods like sandblasting. The back gouge should be at least 1 mm deep and make the surface smooth. For particularly fine requirements, an additional protective layer can be applied to prevent corrosion.