| ‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘ KAWASAKI STEEL TECHNICAL REPORT No.29 ( November 1993 ) Special Issue on Iron Power ‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘ |
| Characteristics and Strengthening Mechanism of Alloyed Steel Powder "KIP SIGMALOY 2010" for Ultra High Strength Sintered Materials Osamu Furukimi, Kei-ichi Maruta, Yoshiaki Maeda |
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Synopsis : The chemical composition of Ni- and Mo-containing composite-type alloyed steel powder was optimized for the production of high strength sintered components via compaction, sintering and heat treatment. A powder with 2%Ni and 1%Mo, KIP SIGMALOY 2010, attained a high tensile strength of 1 920 MPa, a high unnotched. Charpy absorbed energy of 53 J, a high endurance limit of rotating bending fatigue strength of 390 MPa and a high endurance limit of contact fatigue strength of 2 710 MPa, when double-pressed, double-sintered, bright-quenched and tempered. These values were much higher than those of a conventional composite-type alloyed steel powder. The strengthening was attributed to the increase of sintered density and the strain-induced martensitic transformation of the austenite phase. The sintered compacts made from the new powder remained soft before heat treatment and showed a ten-times longer tool life in the case of low cutting speed, compared with that of a conventional composite-type alloyed steel powder. |
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