Welder Qualifications are conducted to ensure the welders are able to produce welds that are acceptable to the requirements of the specification they will be working under. VTS are able to provide fast turnaround of large quantities of welder qualifications.
Bend testing is a method in which a specimen is bent to a specified bend radius. Various types of bend tests are used to evaluate the ductility and soundness of welded joints. Guided bend tests are usually taken transverse to the weld axis and may be bent in plunger type test machines or in wrap-around bend test jigs. Face bend tests are made with the weld face in tension, and root bend tests are made with the weld root in tension. When bend testing thick plates, side bend test specimens are usually cut from the welded joint and bent with the weld cross section in tension. The guided bend test is most commonly used in welding procedure and welder performance qualification tests. This type of testing is particularly good at finding liner fusion defects, which will often open up in the plate surface during the testing procedure.
Macroscopic Examinations (macro tests) are used to assess weld quality. This method of testing typically involves the removal of small samples of the welded joint. These samples are polished across their cross-section and then etched usually by various acid mixtures, dependent on the base material used. The acid etch provides a clear visual appearance of the internal structure of the weld. Particular interest is often shown at the fusion line, this being the transition between the weld and the base material. Such items as depth of penetration, lack of fusion, inadequate root penetration, internal porosity, cracking and inclusions can be detected during inspection of the etched sample. This type of inspection is obviously a snapshot of the overall weld length quality when used for sampling inspection of production welds. This type of testing is often used extremely successfully to pinpoint welding problems such as crack initiation, when used for failure analyses.
VTS is able to conduct Macroscopic Examinations to a variety of metallic welded samples in accordance with all common test specifications as well as weld procedure qualifications.