Structure and Properties of Powder Structural Steels Alloyed with Manganese

摘要

The authors of the present work investigated the manufacturing conditions, structure, and properties of materials, alloyed with 0.5-2% Mn and up to 1% Ni. Manganese was introduced in the form of ferromanganese, whereas carbon was in the form of graphite powder. It was established that the composition, temperature, and sintering atmospheres of the manganese containing steels, all other conditions being equal, strongly influence their microstructure and physical-mechanical properties. After sintering at 1200℃ in a hydrogen atmosphere, the highest level of the physical-mechanical properties is observed in steels containing 1% Mn, 1% Cu; and 0.5-0.6 % bound carbon. Upon hardening and low-temperature tempering, the microstructure of manganese containing steels of the studied compositions changes from a sorbite-troostite to a bainite-martensite one with a microhardness of 2.4-3.5 and 5.9-7.2 GPa, respectively. It was established that some scarce alloying elements (Ni, Cu) could be replaced by manganese, without worsening of the physicomechanical properties of the powder structural steels.