Radiograph Interpretation Of Welds - Easy And Quick Guide

The radiographer should be able to interpret radiographs in addition to being a high-quality radiograph producer. The radiographic interpretation process is divided into three steps: (1) detection (2) interpretation and (3) evaluation. These steps all rely on the visual acuity of the radiographer. Visual acuity refers to the ability of an individual to recognize a pattern spatially in an image. Radiography can be affected by lighting conditions in the viewing area and experience in identifying various features. Am creating this video to help students understand the different types of defects that can be found in weldments, and how they will appear on a radiograph.
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Discontinuities
Discontinuities are breaks in the normal structure of a particular material. These interruptions can occur in the base material, weld materials or "heat-affected" zones. Defects are discontinuities that do not comply with the specifications or codes used to control and invoke an inspection.
General Welding Failures
All types of welding can be distinguished by the following discontinuities.
Cold lap
Cold lap Occurs when the weld filler material does not fuse properly with the base metal, or previous weld pass materials (inter-pass cold lap). The arc fails to melt the base metal enough, causing the slightly molten puddle of weld filler metal to flow into base material without bonding.
Porosity
The result of trapped gas in the metal is the porosity. On a radiograph, porosity appears in many different shapes. It can appear as irregular or round spots, but it is most often seen as a single dark spot or cluster. Porosity can sometimes appear elongated, and even have a tail. The gas is trying to escape from the metal while it is still liquid. This is known as wormhole porosity. The porosity in the material is the result of gas trying to escape while it's still liquid. This is called wormhole porosity.
Cluster porosity
Cluster Porosity occurs when flux-coated electrodes become contaminated by moisture. When heated, the moisture becomes a gas and is trapped within the weld. The radiograph will show the same porosity as a regular one, but it will appear in clusters.
Slag inclusions
Slag Inclusions are nonmetallic solid materials entrapped within weld metal, or between the weld and the base metal. Slag inclusions are visible on a radiograph as dark, jagged, asymmetrical shapes in the weld area or at the weld joints.
Incomplete penetration or lack of penetration
Lack of penetration (LOP), or incomplete penetration (IP), occurs when the weld metal fails to penetrate the joint. This is one of the worst weld discontinuities. A lack of penetration can allow a stress riser to occur, which may lead to a crack. On a radiograph, a dark region with straight edges and well-defined borders appears to follow the land face or the root face through the middle of the weldment.
Incomplete Fusion
An incomplete fusion is a condition in which the weld-filler metal fails to properly fuse with base metal. On radiographs, the condition is usually visible as a dark band or bands oriented along the weld prep or joining area.
Internal concavity (suck back)
Internal Concavity (or suck-back) is a condition in which the weld has contracted and been drawn into the weld root as it cools. It looks like a lack in penetration on a radiograph, but it has irregular edges. The line is also quite wide at the center.
Root undercut is an erosion of base metal near the root of a weld. It appears in the radiographic image as a dark, irregular line that is offset from the centerline. The undercutting process is less straight than LOP, as it does not follow the ground edge.
Offset or mismatch
Offset, mismatch or offset are terms used to describe a situation where two pieces of material are not matched.
The welded-together are not aligned properly. The radiographic image shows that the welded together are not properly aligned. The difference in density is noticeable between the two pieces. Difference in density the difference in thickness of the material is responsible for the dark, straight line. The difference in material thickness is the cause of the dark straight line. The failure of the weld to fuse with land area.
Inadequate weld reinforcement
Inadequate Weld Reinforcement is a part of a weld in which the thickness of the weld is inadequate. The thickness of metal deposited is smaller than that of the base material. It is easy to Radiographs can be used to determine if the weld is not sufficiently reinforced. The image density will be greater (darker) in the area suspected of being inadequate. Image density of the base material.
Excess Weld Reinforcement. Excess Weld Reinforcement is a part of a weld where weld metal has been added, Exceeding the limits of engineering drawings or codes. The appearance on a radiograph shows a lighter, localized area in the weld. Visual inspection c