Definition - What does Weld Root mean?
The weld root is the point at which the back of a weld intersects with the base metal surfaces. It determines the weld penetration and fusion to form a rigid joint. It is made by the first root pass and supported by other passes.
This is the part of a weld that is situated at the bottom that is used to determine the throat of a weld, according to welders’ codebooks. This is the focal point of the concave side of a weld. It is observed in a fillet weld, groove weld and v-groove weld on pipe works. It is produced in consumable electrode and non-consumable electrode welding processes.
Corrosionpedia explains Weld Root
The welding technique and the features of the part will determine the quality of a weld. The presence of the root determines how the two surfaces are fused together. The root is formed by a weld pool that develops when welding starts, which in turn controls the degree of penetration. The material thickness, arc length root face and root gap are valuable determinants of this feature.
The weld root can be directly inspected by particle inspection technique (penetrant or magnetic) and indirectly determined by ultrasonic or radiography techniques.
The strength of the weld root gives the structure its resistance against impact, vibrations and corrosion by weathering. Imperfections brought about by defects caused by the weld root create suitable conditions (e.g., cracks, porosity and inclusions) for corrosion.