Vacuum furnace for continuous heat treatment of metals - esp. for hardening saw blades made of high speed steel

摘要

The furnace consists of a tubular casing with an inlet- and exit- air lock so a vacuum can be achieved. In the casing is a muffle with an inverted "U" cross-section; and inside the muffle are two rows of heating elements, one row near each muffle wall. The muffle has sliding doors; and a row of trolleys travel below the open base of the muffle. Each trolley carries a profiled pedestal made of a refractory and closing the base of the muffle; and the workpieces being treated are located on the pedestals. The exit air lock is pref. equipped with quenching appts. Used for thermal- or thermochemical treatments, but esp. the hardening of high speed steel parts. Low energy consumption when heating steels to e.g. 1200 deg.C, while avoiding the pollution caused by salt baths.