PROPERTIES AND MICROSTRUCTURE OF FE-1,5MO POWDER STEEL SINTERED WITH A LIQUID-PHASE ON THE BORON BASIS

The knowledge about microstructure and properties of sintered Fe-Mo-B steel prepared from prealloyed Fe-1.5Mo powder with addition of 0.2-0. 6% B are summarized in this paper. The eutectic phase activating the d ensification of sintered systems is formed at temperature of 1174 degr ees C. The boride formation by interaction between boron and alloyed m atrix leads to the decrease of liquid phase quantity and to the increa se of matrix microhardness. The density of compacts from Fe-1.5Mo powd er with 0.6% B addition increases by 5.8% after sintering at the tempe rature 1200 degrees C/60 min/diss. NH3. Equally sintered systems with 0.4% B addition reach the tensile strength 550 MPa and ductility 5%.