Intermediate Patenting

The patenting process first involves heating the wires in an austenitizing furnace (usually direct fired or muffle tube) to about 950°C in order to form a uniform austenite structure of largish grain size. Fluidbed austenitizing furnaces have an advantage of significantly higher heat-transfer and therefore faster wire speed, but have issues with atmosphere control and scale formation. Following a rapid quench in lead, fluidbed or water/foam the resulting structure is a very fine perlite that exhibits greater ductility and the ability to be redrawn. The wires are then rapidly descaled in acid before a final surface treatment in phosphate and/or borax.

Key aspects of the process include accurate atmosphere and temperature control in the austinitizing furnace to insure minimum scale formation and no decarburization. The quenching stage requires rapid cooling to “get under the nose of the curve” (left of the TTT curve) and sufficient holding time to avoid coarse perlite. Lead quenching is generally recognized as providing the best metallurgical results, although the modern control systems of both fluidbed and water/foam quenching systems can produce a fine perlite structure.

Wire Products:

Wire Rope
Crane Rope
Bridge Wire
Stay Cables
Catenary Cables
Hoist Ropes
Tire Cord & Tire Bead

QED’s strength is in our furnace design experience and advances in combustion and control systems. Our patented “Pressure Control” system offers excellent combustion turn-down ratios that corresponds directly to permitting a very wide range of production rates (from zero to full production).