Complex effects of alloy composition and porosity on the phase transformations and mechanical properties of powder metallurgy steels

• Composition and porosity affect phase transformation and mechanical behavior.
• Strength and hardness of sintered compacts decrease with increasing porosity.
• Work hardening rate of sintered compacts increases with increasing porosity.
• Phase transformation in porosity-free samples was simulated by JMatPro®.
• A model was formulated by combining porosity effect models with JMatPro results.

In this study, the combined effects of alloy compositions and porosity in powder metallurgy (P/M) steels on the phase transformation and mechanical properties were investigated. First, carbon steels and Astaloy CrM (Fe–3.0 wt.% Cr–0.5 wt.% Mo) steels with various porosities were produced using powder metallurgy routes, and their microstructure and mechanical properties were examined. Then, the phase transformation and resulting mechanical properties of porosity-free samples were simulated using the commercial software JMatPro® to examine the sole effect of alloy composition. By combining the porosity effect fitting models with the JMatPro results, we attempted to formulate a mathematical material model that describes the mechanical behaviors of the P/M steels.

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