High temperature sintering of low-alloyed steels: effect on mechanical properties and on the dimensional and geometrical precision

The influence of high temperature sintering (HTS) on the microstructure and the dimensional stability of ring specimens was investigated in a previous EPMA Club Project. HTS improved density and porosity morphology and did not impair dimensional and geometrical precision. A second Club Project was therefore carried out, to investigate mechanical properties and precision of parts characterized by a complex geometry. Three low alloyed steels with either a very low amount of Ni or Ni-free were used. The manufacturing process was carried out in industrial plants. The results confirm that HTS does not impair dimensional and geometrical precision and allows to achieve better tensile strength, slightly lower tensile elongation and impact strength than those of high Ni diffusion bonded steel sintered at 1120°C, taken as a reference. HTS widens the possibilities for new alloy systems with opportunities to reduce cost and achieve improvements related to processing rules (REACH).