1995 Volume 81 Issue 8 Pages 833-838
A prealloy steel powder which was Mn-less, contained 1Cr-0.3Mo and low oxygen was developed to improve compressibility of steel powder, tensile strength and toughness of sintered compact.
This newly developed steel powder showed high compressibility of green density of 7.15Mg/m3 at 690MPa of compacting pressure. This is derived from the decrease in solution hardening effect and Mn oxide on powder surface with decrease in Mn content.
The sintered compacts made from the new powder with 0.9% graphite addition gave a tensile strength of 900MPa and a Charpy absorbed energy of 17J, when compacted at 690MPa and sintered at 1150°C. These values were higher by 200MPa and 3J, respectively, than those of compacts made from a conventional 1Cr-0.3 Mo-0.7 Mn steel powder.
The strength and toughness improved, respectively, because of the production of fine pearlite structure and the decrease in Mn oxide with decrease in Mn content.
