In order to ensure that the graphite electrode is reliably connected, not loose, not tripped and not easy to break during use, the machining of graphite electrodes must achieve high precision. The processing accuracy of electrodes and joints directly affects the connection quality of electrodes and joints, and the connection quality of the two has a great influence on the normal operation of the electric furnace and the consumption of electrodes. The processing accuracy of graphite electrodes is greatly affected by the accuracy of the processing equipment itself, and is also related to the tools used, cutting parameters and the operator's operating level.
In China's graphite electrode quality standard, for graphite electrode size deviation and thread shape processing accuracy, only the maximum value of the positive deviation of the electrode joint hole diameter and the maximum value of the negative deviation of the joint diameter are specified, and the gap between the end faces of the two electrodes is not greater than 0.4mm , The deviation between the electrode body and the centerline of the joint hole is not more than 0.3mm, but there are no clear regulations on other aspects (such as pitch deviation, thread taper deviation, etc.). Therefore, graphite electrode manufacturers should formulate internal control standards for processing accuracy according to the user's requirements and the actual situation of the factory.
Using a specially designed combined machine tool for processing, the processing accuracy of graphite electrodes can generally reach the following levels:
(1) Process the electrode body (conical joint connection). Outer diameter conicity: less than 0.15/2500mm, thread effective diameter deviation: 0~+0.1mm, thread taper deviation:
+ 1'~-2', thread pitch deviation: less than 0.02/50mm, thread depth deviation: ±0. 01mm, end surface unevenness: less than 0.05mm.
(2) Processing joints (tapered joints). Joint effective diameter deviation: ±0.03mm, taper deviation: less than +2', thread pitch deviation: ±0.03/300mm, length deviation: 0~-2mm, parallelism deviation of both ends: less than 0.1mm.
Post time: Apr-24-2023