graphite electrode menards
graphite electrode menards
What are the accuracy deviations of graphite electrode during machining, and what are the consequences during use?
(1) The center line of the graphite electrode body does not coincide with the center line of the joint hole, and the deviation of the center line exceeds the standard. After the upper and lower graphite electrodes are connected, there is an untouched part on the edge of the electrode end surface, which not only affects the flow of current, but also increases the end surface of the graphite electrode.çš„oxidation area.
(2) The upper and lower end faces of graphite electrode are not parallel or the center line of graphite electrode body is not perpendicular to one end face. After the two electrodes are connected, one end face is pressed and contacted, and there is a gap on the other side. Current cannot pass uniformly on the end face, resulting in local temperature. Too high. In addition, the axes of the upper and lower graphite electrodes are not in a straight line, and the joints are unbalanced. Once they are hit by strong vibration or collapse, the joints will easily break.
(3) The thread pitch of the female thread of the joint hole of the graphite electrode is processed according to the positive deviation, while the thread pitch of the male thread of the joint is processed according to the negative deviation. After the two are connected, the thread will only touch the end and the bottom, and the side of the thread will not touch, and There is also a gap between the end faces of the upper and lower graphite electrodes, which seriously affects the passage of current, and the temperature of the joint rises quickly, which can easily cause the joint to break.
(4) The taper of the graphite electrode joint is processed according to the positive deviation, while the taper of the electrode joint hole is processed according to the negative deviation. After the two are connected, only the part of the thread on the outside of the joint hole near the end face is in contact with the part of the thread near the end face of the joint. tight connection.
(5) When there is a deviation of the thread angle or the center line of the thread angle, the threaded surface of the connector and the electrode connector hole is not surface contact, but point contact or line contact, which will inevitably affect the flow of current, and the consequences will be related to the thread pitch. It is the same when the deviation is too large.
(6) If the graphite electrode joint hole diameter is processed according to the maximum allowable deviation, and the joint diameter is processed according to the minimum allowable deviation, then, although both meet the standards, they will inevitably become loose after connection. Under the strong vibration of the graphite electric furnace , The joint and the graphite electrode at the lower end are easy to fall off.