Studies Regarding the Die Pressing Parameters on the Press Ability of Cementite Powders in Order to Obtained Sintered Steels

摘要

This paper presents the experimental results of the effects of the pressing speed on the press ability of the cementite powders alloyed with iron powders, in order to obtain sintered steels. Cementite or iron carbide is a chemical compound with Fe_3C formula having orthorhombic crystal structure. Regarding mechanical properties, cementite is hard and brittle being important in the metallurgical processes. For the research process was used a mixture consists by cementite and iron powders (6,75%Fe_3C+93.25%Fe) which was obtained by mechanical alloying technique for 30 hours. The cementite powders were produced by direct carburizing of Fe powders. The mixture was unilateral die pressing at three pressures 200, 400 and 600 MPa respectively 5 pressing speeds 10 up to 50 mm/min. The green billets were sintered in argon atmosphere and were studied by microstructural point of view. The evolution of microhardness function the pressing parameters was studied too.