The weld face is the exposed surface of a fusion weld on the side from which the welding was performed. In simpler terms, it's the part of the weld you see after the welding process is complete, before any post-weld treatments are applied.
Understanding the Weld Face
The weld face's appearance can provide valuable information about the quality and consistency of the weld. Factors influencing the weld face include:
- Welding Technique: The specific welding method used (e.g., SMAW, GMAW, GTAW) directly affects the weld face's characteristics.
- Welding Parameters: Current, voltage, and travel speed influence the weld bead's size, shape, and surface texture.
- Electrode/Filler Metal: The type of electrode or filler metal used impacts the weld face's composition and appearance.
- Shielding Gas: The shielding gas employed (if applicable) affects the weld face's oxidation level and cleanliness.
- Base Metal Cleanliness: Contaminants on the base metal can lead to defects visible on the weld face.
Characteristics of a Good Weld Face
A desirable weld face typically exhibits the following characteristics:
- Smooth and Uniform: The surface should be relatively smooth, with consistent bead width and height.
- Proper Wetting: The weld metal should smoothly blend into the base metal without undercutting.
- Absence of Defects: The weld face should be free from visible defects such as porosity, cracks, and slag inclusions.
- Correct Reinforcement: The weld should have the appropriate amount of reinforcement (the height of the weld bead above the base metal surface) as specified by the welding code or engineering requirements. Too much or too little reinforcement can weaken the joint.
Importance of Visual Inspection
The weld face is a primary focus during visual inspection, a critical non-destructive testing method. Inspectors examine the weld face for any imperfections that could compromise the weld's integrity. Issues identified on the weld face often warrant further investigation using more advanced non-destructive testing techniques.
