The Improvement on Decarburization of S55C for the Linear Guild-Rail in #1 Bar Mill

摘要

Decarburized steel causes several problems, for example, lowering of hardness and fatigue life, when it is used to manufacture auto parts or mechanical parts. The main mechanism of decarburization is related to diffusion and oxidation of carbon during reheating of the billet. The key factors of the process are furnace temperature, heating time, furnace atmosphere and oxygen content, are all studied by introducing the Taguchi experiment. In this study, a more specific effect of these factors are compared and identified, which indicates decreasing furnace temperature from 1050°C to 970°C, optimizing the scheduling plan for stabilizing the furnace temperature to meet the low temperature rolling process, and lower the air-fuel ratio are essential measures to reduce decarburization. Through these improvements, the accepted decarburization rate increased from 72% to 99.86% and thus obtained annual benefits of 10.72 million NT dollars. In addition, customers can consequently benefit from reducing the sandblasting process and save 43.6 million NT dollars per year.