The partial cause of graphite electrode breakage lies in operational and control aspects, but the quality of the electrode itself also plays a decisive role in its breakage. Today, let’s delve into one of the reasons behind electrode breakage: issues stemming from the electrode’s own quality.
(1) Causes of Nipple Breakage: The graphite nipple plays a critical role in connecting graphite electrodes during steelmaking, and its quality directly affects the electrode’s performance in the electric furnace. The connection area formed by the graphite electrode and the nipple is subjected to significant electrical, thermal, and mechanical loads, making it a common site of fracture. Data indicates that over 80% of electrode usage accidents in steelmaking electric furnaces result from nipple breakage or loosening. Factors contributing to nipple breakage include low volume density, leading to lower strength and increased susceptibility to fracture during usage; higher electrical resistance, causing rapid temperature rise at the joint during energization and increasing the likelihood of fracture due to higher thermal stress; inadequate flexural strength of the graphite electrode nipple; significant risks posed by the inclusion of internal cracks in the finished graphite nipple; and mismatched machining precision between the graphite nipple and the electrode, which also increases the risk of breakage.
(2) Reasons for Electrode Breakage: While the probability of electrode breakage is generally low, it can occur due to several factors: quality defects in the electrode screw holes; insufficient volume density and strength of the electrode; mismatch between the specifications and machining precision of the electrode and the nipple; deep cracks occurring at the electrode ends due to poor resistance to thermal shock; and the presence of transverse cracks within the electrode that go undetected when incorporated into the finished product, posing significant breakage risks.
As for how to prevent electrode breakage, we will discusss it in the next article.
