Continuous heat treatment of fine drawn wire - which travels at controlled tension and exceptionally high speed through furnace

摘要

The wire is drawn tangentially, and using a controlled tension (t1) from a storage spool (a) driven by a motor (1), the r.p.m. of the latter being controlled by tension (t1). The wire then travels vertically through a heating zone (b) and is wound at a controlled tension (t2) onto a collector spool (c) driven by a motor (2), the r.p.m. of the latter being controlled by tension (t2). Several wires are pref. treated in a row of vertical zones (b), each consisting of a heating zone in series with a cooling zone. Zones (b) may be formed by a row of tubes, or by one furnace using a row of inlet- and exit- guide bushes for the wires. H2 is pref. fed through zones (b) to form a protective atmos. and burned on leaving the zones. Used for annealing wire made of stainless steel, Cu, bronze, Ag, etc., 0.02-0.25 mm dia. The wire can travel at up to 300 m/minute.