公开(公告)号：WO2004082872A3

公开(公告)日：2005-04-07

申请号：PCT/US2004008199

申请日：2004-03-17

Applicant: PENN STATE RES FOUND

Inventor： SONTI NAGESH ,  AMATEAU MAURICE F ,  RAO SUREN B

IPC: B21H5/02 ,  B22F3/16 ,  B22F3/24 ,  B22F5/08 ,  C21D1/19 ,  C21D1/42 ,  C21D8/00 ,  C21D9/32 ,  C21D1/10

CPC classification number: B22F3/162 ,  B21H5/022 ,  B22F3/16 ,  B22F3/164 ,  B22F3/24 ,  B22F5/08 ,  B22F2998/00 ,  B22F2998/10 ,  B22F2999/00 ,  C21D1/19 ,  C21D1/20 ,  C21D1/22 ,  C21D1/42 ,  C21D8/00 ,  C21D9/32 ,  Y02P10/253 ,  Y10T74/1987 ,  B22F2003/241 ,  B22F2003/248 ,  B22F3/18 ,  B22F3/14 ,  B22F2202/07

Abstract: A technique for net shaping gear teeth of a high performance power transmission gear from a powder metal workpiece (42) includes heating a powder metal workpiece (42) in the form of a near net shaped gear blank having gear teeth surfaces above its critical temperature to obtain an austenitic structure throughout its surfaces, isothermally quenching the workpiece (42) at a rate greater than the critical cooling rate of its surfaces to a uniform metastable austenitic temperature just above the martensitic transformation temperature, rolling the gear teeth surfaces of the workpiece to a desired outer peripheral profiled shape between opposed dies (44, 46), each die (44, 46) having an outer peripheral profiled surface, while holding the workpiece (42) at the uniform metastable austenitic temperature, the gear teeth surfaces undergoing densification, plastic deformation, and strengthening as a result of the rolling operation, and cooling the workpiece (42) through the martensitic range to thereby harden the surfaces of the gear teeth.

Abstract translation: 一种用于净化来自粉末金属工件（42）的高性能动力传动齿轮的齿轮齿的技术包括将具有高于其临界温度的齿轮齿表面的近网状齿轮坯料形式的粉末金属工件（42）加热到 在其整个表面上获得奥氏体结构，以大于其表面的临界冷却速率的速度等温骤冷工件（42）至恰好高于马氏体相变温度的均匀亚稳态奥氏体温度，将工件的齿轮齿面滚动到 在相对的模具（44,46）之间期望的外周轮廓形状，每个模具（44,46）具有外周轮廓表面，同时将工件（42）保持在均匀的亚稳态奥氏体温度，齿轮表面经历致密化，塑性 变形和强化，并且将工件（42）通过马氏体范围冷却至t 因此硬化齿轮齿的表面。