Possibility of utilizing water-atomized Fe-Ni-Mo steel powder as base materials for warm compaction process

Abstract

Water-atomized Fe-Ni-Mo steel powder, was utilized as base powder for designing powder mixtures for warm pressing. The warm pressing and sintering behaviours of the powder mixtures were studied. The results show that, compared with the pressing at room temperature, the green density gain by warm pressing is within a range of 0.10–0.19 g/cm3 and reduction in spring back is 30%–40% of the ambient, and maximum green density of 7.32 g/cm3 at 735 MPa is obtained as the graphite mass fraction is 0.8%. It was found that sintered densities of the compacts were reduced slightly due to releasing of elastic stress stored in the compacts during sintering. The warm pressing of steel powders gives evidence for substituting the traditional double pressing and double sintering process.