Effects of temperature and oxygen concentration on the characteristics of decarburization of 55SiCr spring steel

Abstract

Effects of temperature and oxygen concentration on decarburization of 55SiCr spring steel were investigated at the temperature range of 500°C-1 200°C by using a Muffle furnace (an atmosphere of ambient air) and a Simultaneous Thermal Analyzer (low oxygen concentration with 2% O2and 98% N2). In ambient air, the decarburization behavior can be divided roughly into five temperature ranges: T≥1200°C, no decarburization; TG (A3for 55SiCr when its carbon concentration equals to zero) <700°C, no decarburization; T>700°C, only partial decarburization. Lower oxygen concentration results in decrease in a growth rate of the oxide scale and leads to different characteristics of decarburization.