One-Step Enameling and Sintering of Low-Carbon Steels

Abstract

Powder technology allows manufacturing complex components with small tolerances, saving material without subsequent machining. There is a growing trend in using sintered steel components in the automotive industry. Within 2020, about 2544 million US dollars was invested for manufacturing sintered components. Not only does this industry uses steel components, but the gas cooker industry also uses steel in its burners since they are robust and usually demanded by Americans, with forecasts of 1097 million gas cookers in 2020. Steel gas burners have a ceramic coating on their surface, which means that the burner is manufactured in two stages (casting and enameling). This work aims to manufacture the gas burners by powder metallurgy, enameling and sintering processes in a single step. To achieve this aim, the ASC100.29 iron powder has been characterized (flow rate, relative density and morphology); subsequently, the most suitable parameters for its compaction and an adequate sintering temperature were studied. Single-step sintering and enameling was achieved by compacting iron powder at 500 MPa and sintering at 850 °C for 5 min. The necessary porosity for mechanical anchoring of the coating to the substrate is achieved at this sintering temperature. Bending resistance tests, scratching, degradation under high temperature and basic solution and scanning electron microscopy were used to characterize and validate the obtained samples.