నైరూప్య

Test of elaboration protocols for obtaining highly Co- or Ni -alloyed spheroidal cast irons from an industrial SGcast iron. part a: first protocol. subpart 2:mechanical properties

KamelMeridja, Patrice Berthod

In the first part of this work flake graphite cast irons highly alloyed with either cobalt or nickel were obtained instead the wished spheroidal graphite ones. However themicrostructures were rather interesting and it waswished here to specify their mechanical properties. Compression tests were carried out on the two highly alloyed cast irons and on the {only iron}- based cast iron prepared following the same route for comparison. Thanks to its ferrite-pearlite matrix the cast iron containing only Fe displayed the highest values in yield strength (660 MPa) and hardness (about 600Hv10kg), among the three materials. The {cobalt=iron}cast iron and the {nickel=iron}cast iron presented much lower yield strength (about 220MPa) and hardness (100-200Hv10kg). Compression induced a softening of the {only iron}-based cast iron the hardness of which came back at the same level as the hardened Co or Ni containing cast irons. The densities of the three cast irons are also estimated and commented.