PRODUCTION OF SINTERED CONNECTING ROD HAVING HIGH STRENGTH

摘要

PURPOSE:To produce a connecting rod having a high-strength central part and end parts of excellent machineability by cooling quickly the I-shaped part at the center of the section to execute cooling after sintering in the stage of subjecting metallic powder for powder metallurgy to compaction molding and sintering the molding to produce the sintered connecting rod. CONSTITUTION:The powder of lead stearate as a lubricating agent is added and mixed at 0.5-1.0% to and with the Fe metallic powder for powder metallurgy and the mixture is subjected to compaction molding to the shape of the connecting rod. The molding is heated and sintered in a non-oxidative atmosphere by which the sintered body of the connecting rod is produced. The I sectional part 1a in the central part of the section is quickly cooled and hardened by an atmosphere gas 4 for cooling ejected from a nozzle 3 to improve the strength in this part. The large end 1b and small end 1c of the connecting rod are slowly cooled without quick cooling, by which the hardening of the material is obviated and the machineability is maintained.