Improvements in and relating to electrodes for the electric heat treatment of metallic articles

Abstract

Abstract 325,552. Thompson, F. W. Oct. 18, 1928. Divided on 328,270. Heating by electricity.-In apparatus for heating metal bars by passage of current therethrough e a c h electrode comprises a number of elements providing paths of different electrical resistance so that a desired temperature gradient is obtained over the contacting portions of the bar and electrode. The temperature gradient will also depend on the heat conductive properties of the elements. Two or more electrodes 7 are arranged at each end of the bar A to form clamping jaws. Each electrode is dovetailed into a water-jacket 3 mounted by means of a ball and socket joint on a rod 1. In Fig. 4 the electrode comprises a silicon chromium block 10 and copper strips 29 - - 34. A thin carbon strip 35 may be embodied in the electrode to produce a reducing atmosphere. In Fig. 5 a corundum member 36 enclosing a copper pin 37, and an additional copper strip 38 are employed. In Fig. 8 the electrode comprises strips 14 - - 17 of materials of different electrical conductivity mounted in a copper block 13. In one modification thereof the centre of the strips are removed and the interstices are filled with a refractory cement. In another modification, the strips are of different length and cross section 1 and may be of the same material if desired.

Inventors

No inventors recorded.

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