EFFECT OF HEAT TREATMENT ON THE STRUCTURE AND MECHANICAL PROPERTIES OF PM Fe-Si-B COMPACTS THROUGH VACUUM CARBURISED

This paper was aimed at determining the influence of heat treatment on structure and selected mechanical properties of sintered steel obtained through vacuum carburising of iron compacts with additions of boron and silicon. Vacuum carburising with immediate sintering of the compacts made of a mixture of iron ASC100.29, ferroboron and silicon powders was carried out at 1050 and 1150°C in a laboratory vacuum furnace. The effect of quenching in oil and low-temperature tempering on the structure of surface layer and core, as well as selected mechanical properties of the sintered steel was studied. As a result of applied heat treatment, an increase of 74% of ultimate tensile strength, from 712 MPa to 1228 MPa, was obtained.