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% O2 and 98% N2). In ambient air, the decarburization behavior can be divided roughly into five temperature ranges: T≥1 200°C, no decarburization; TG (A3 for 55SiCr when its carbon concentration equals to zero)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.KEY WORDS: 55SiCr spring steel; complete decarburization; partial decarburization; oxygen concentration; growth rate of oxide scale.

No abstract