Introduction to Non-Destructive Welding Inspection
Weld inspection is vital to assure safety and structural soundness on the vast number of products and projects where strong, secure welds are vital. Weld inspecting is a complex science; in this article we will examine the basics of welding inspection. Specifically – what methods do welding inspectors use to inspect and judge the strength of welds?
The Very Basics
For any welding inspector, the best and most basic tools they have are their eyes. In many situations, visual inspection will be all that is required of a welding inspector. Visual inspection is without doubt the most widespread technique of non-destructive weld inspection.
The most common welds that will need to be inspected visually are fillet welds. Whether the weld meets specification is easy to determine: If the plans call for a 5/16th weld, then the weld must at least meet that dimension or its strength will be under what the engineers calculated. A standard tool of the trade for measuring this is the fillet weld gauge.
The profile of all welds need to be checked, and should display a smooth, consistent concave or convex profile, depending on application.
All welds need to be inspected for defects visually. Cracks in the surface of the weld are always unacceptable. An occasional incidence of porosity in the weld may or may not be acceptable, depending on application. Craters, places where the weld is not filled to its full cross-section, are stress points that may cause cracking and are unacceptable. Undercut, caused by excessive current for the welding application, should also be checked for visually. Arc strikes in the base metal outside the welding zone should be looked for and removed by grinding.
Additional Welding Inspection
But welding inspectors cannot rely completely upon their eyes alone. To see what the human eye cannot, a variety of ultra sonic and angled beam transducers equipment is used. The most common application for ultra sonic testing will be girth welds on pipelines. An ultra sonic emitter is mounted on a ring with is placed around the pipe to be tested. Rotated all around the weld, the extremely high frequency sound waves pick up even the smallest flaws in the weld. Ultra sonic testing of this nature saves millions in man-hours the pipeline industry every that would otherwise be lost finding and repairing leaks by trial and error.
Welding Inspection Available at Tulsa Welding School
If you’re interested in learning welding inspection and getting hands-on experience inspecting welds you should contact Tulsa Welding School today! Our Associate of Occupational Studies program is only available at our Tulsa, Oklahoma, campus.