Critical component failures often make the headlines, whether occurring at sea, underground, in mid-air or in production plants. Faulty pipes, valves, shafts, gears, couplings and other engineered components give rise to safety, environmental, productivity and financial issues, some catastrophic. These failures might result from design, manufacturing and assembly errors, inadequate quality assurance or unforeseen operating conditions, but sometimes they relate just to substandard materials and improper processing treatments.
Independent metallurgical specialist, Keighley Laboratories, points out that with growing volumes of steel, alloys and metal components being sourced in the Far East from comparatively unknown suppliers, and manufacturers in this country ultimately responsible for any component failures, there is now a pressing need to re-inspect, or overcheck, material certifications. In support of this view, the company draws attention to a recent US study, in which 133 out of 220 samples of imported steel rod were rated as failures by a certified test laboratory, an astonishing 60% failure rate.
“If you have specified imported material to a particular grade or heat treatment process, then overchecking is the best way to ensure you are getting what you paid for,” says Keighley Labs Heat Treatment Commercial Manager, Michael Emmott. “Often we find that the raw material is not as specified, even with the correct certification, creating potential problems down the line.”
“The cost of a simple chemical or mechanical overcheck or a full in-depth metallurgical analysis might be tens or hundreds of pounds, but if that item is safety critical or forms part of a product worth hundreds of thousands, then it’s a comparatively small price to pay,” he continues. “Besides, given the legal implications of a failure in the field, it’s either a question of verifying incoming material or possibly putting your own business at risk.”
Through its in-house Technical Services laboratory, Yorkshire-based Keighley Labs is able to provide independent chemical analysis, employing state-of-the-art spectroscopy or classical wet methods; microscopic sample examination, using metallography techniques; and mechanical testing for impact resistance, hardness, ductility, tensile strength and durability. In addition to overchecking certificated materials, these specialist techniques are also used in the allied fields of reverse engineering and failure investigation.
Reverse engineering refers to the process of duplicating an engineered component or assembly without recourse to drawings, CAD files, specifications or documentation, determining exactly how it was originally made and treated and from what material. Keighley Labs employs laboratory and CAD/CAM resources to model parts to a high degree of accuracy, then if necessary it will project manage the casting, machining and heat treatment of single or multiple components.