Evaluation of using acetylene as carbon source in the carburization of steels

For this purpose, a gaseous carburizing system was designed and manufactured with the following characteristics: controlled production of a carburant gaseous atmosphere, inert and hermetic isothermal reaction zone and carbon/oxygen probe for the control of carbon potential (Cp) during the carburization cycle.

An atmosphere composed of synthetic endothermic gas with composition of 40%H2, 40%N2 and 20%CO and constant flow of 100 cm3/min and acetylene variations with flows of 40cm3/min, 65cm3/min and 85cm3/min was used. These gases were injected into the reactor at 900°C and held for three hours. The acetylene gas was selected as the carbon-enriching agent in the atmosphere, due to the high decomposition ratios of these molecules and the low tendency to develop polymerization reactions.