EoW September 2009

Feature

Photo courtesy of C M Caballé SA

Steel wire, cable & rod T he needle-makers credited with the development of steel wire were custom craftsmen by the standards of any period. They worked for a select group of clients – themselves. They perfected a single elegant mechanism – the aperture. They preserved the integrity of their art by reposing their secrets in a guild. The steel wire makers of today have a more complicated time of it. Even in the brief interlude between rolling and drawing they must cope with a pair of colour-coded menaces: the magnetite (Fe 3 O 4 ) blue oxide that forms on the wire as it cools following the rolling process; and the maghemite (Fe 2 O 3 ) red surface oxide, or rust, that forms during shipping and storage. Decisions have to be made as to the best scale-removal method. Is it to be acid pickling? If so, which kind: chemical – or electrolytic? Perhaps mechanical descaling is preferable. Or abrasive blasting or sanding. Or shaving. The latter-day artisan will already have confronted the challenges presented by the wire rod. Any miscalculation or variation as to temperature or ferrous content – during pouring, rolling, or treatment – will likely present as a defect which, magnified throughout the production process, means major trouble with the drawing dies. The check-list may be very much longer. But the ideal served in a modern steel wire making plant is traditional, and simply stated: that the product be perfect of kind. The suppliers reviewed in this section of EuroWire are able partners in the enterprise.

48

EuroWire – September 2009