Effect of Increased Post-Sinter Cooling Rate on Properties of Ferrous P/M Materials with Low Hardenability

摘要

The author believes a niche exists for powder-metallurgy (P/M) materials with yield strengths in the range of 450 - 600 MPa (65 - 87 X 10~3 lbf-in~(-2)). Such properties can be obtained with P/M alloys based on plain iron - i.e. without additions of molybdenum, nickel or other elements to enhance hardenability, or with such additions minimized, by applying forced convection to increase the rate of post-sinter cooling. Increase in strength can be attributed to refinement of the pearlite/ferrite microstructure and/or reduction of the pearlite inter-lamellar spacing. In this study, the effect of composition and post-sinter cooling rate on 0.2% offset yield strength will be investigated. Materials will be studied metallographically to assess the effect of input variables on microstructure.