Design and implementation of a gas cementation system for surface treatment of steels

Abstract

This article describes the design, construction and testing of a laboratory scale equipment for thermal treatment with controlled atmosphere for the study of steel gaseous carburization. The machine has the following characteristics: controlled production of a gaseous atmosphere consisting of a synthetic endothermic gas mixture (20% CO, 40% N2, and 40% H2) and acetylene (C2H2), providing the possibility of obtaining different carbon potentials (Cp) and the isothermal, inert and hermetic reaction zone. For equipment tuning it has been used samples of AISI-SAE 1020 steel, this material is commonly used in the manufacture of pieces like bushings, sprockets, pins and rollers, which require a depth of total cemented layer up to 1.2mm. In cemented samples microstructure were characterized by optical microscopy, chemical composition by optical emission spectrometry and mechanical properties by Vickers microhardness cross section scattering. The results show an enhenced control and efficiency in the carbon transfer during the carburization cycle with acetylene addition, favoring resources optimization and time processing.