As-sintered AISI 440C stainless steels with improved hardness and corrosion resistance
AbstractPreliminary work on powder
metallurgy (PM) AISI 440C steel with 1.2 w/o C indicated that it is possible to achieve acceptable hardness in the as-sintered condition, but with inferior corrosion resistance. To address this limitation, a series of simulations were carried out using
Thermocalc software to predict alloy compositions and sintering temperatures for achieving optimum
properties. The simulations served as the basis for the design of a Taguchi trial run with an L9 orthogonal
array. Test samples were characterized utilizing microindentation hardness and salt-spray-corrosion testing. Microstructural analysis was also used to characterize and interpret the observed behavior. The results show that AISI 440C with 0.95 w/o C and
200 ppm B sintered at 1,220°C gives an optimum combination of the assintered roperties.