总第172期 2010年2月
文章编号：10099700(2010)010031-03
南方金属 SOUTHERN METALS
齿轮齿根的率硬层深度研究
王能为
（攀枝花学院材料工程系，四川攀枝花617000）
Sum.172
Fabruary
2009
要：研究了齿轮的整体高频泽火工艺，通过不同的率火时间（分别为12s和17s)获得了不同的硬化层.利用显搬
微硬度计测出了齿轮齿根不同厚度的硬度，绘制出了硬度变化规律曲线，并根据经验公式分别测算得到了它们的淳硬层深度.同时利用扫描电镜（SEM)对齿根的率硬层部分进行了显微组织观累，发现不同的泽火时间在硬化层处获得了不同的率火组织，淳火时间12s组织为马氏体+铁素体+残余奥氏体，淬火时间为17s组织为马氏体+
极少量针状铁素体+残余奥氏体，后者组织更均匀，强度更高，因此工艺更理想，关键词：高频泽火；齿根；泽硬层深度；显微组织。
中图分类号：TG142.1；TG156.3
文献标识码：A
A study of the hardened layer at a gear tooth root
WANG Neng-wei
(Department of Materials Engineering, Panzhihua University, Panzhihua 617000, Sichuan)
Abstract: An high-frequency overall quenching process for a gear was conducted, in which various hardened depths at the tooth root were obtained in accordance with the holding time used(12 and 17 seconds). The microhardness at the root was tested by microhardness tester at various hardened depth, and corresponding curves of microhardness vs. hardened depth were drawn, based on which the overall depth of the hardened layer could be estimated by means of an empirical formula. Meanwhile, the microstructure of the quench-hardened layers were observed by scanning electron microscope( SEM) , show-ing that the microstructure produced by 12 second holding was composed of martensite, ferrite and residual austenite, while that by 17 second holding composed of martensite, small amount of acicular ferrite and residual austenite. The microstruc-ture yielded by the 17 second quenching was more uniform and stronger than that by the 12 second quenching, thus sugges-ting that the 17 second quenching process was better than the 12 second one.
osoo rake poapre o da aeae o roo ron uoan oanbe srom a
0引言
齿轮是机械传动中最普遍最常用的零件，它起着传递动力、变速和改变运动方向等重要作用.为满足齿轮的各种技术要求[1-2]，齿轮应具备高弯曲疲劳强度和高接触疲劳强度，齿面有高硬度及高耐磨性，心部应有足够的强度和韧性，同时应具有良好的冷、热加工的工艺性等.为此，齿轮在使用前往往要进行高频率火处理.图1所示为高频率火装置，
齿轮高频火采用两种方式：对于高负荷，中小模数的圆柱齿轮、伞齿轮等采用整体高频率火；而对于低负荷.大中模数的斜齿轮、宽状齿轮等则往往采用单齿高频率火.就整体率火而言，成本较低，轮齿强
收稿日期：20090612
度大，率火自由度也大，并且有可能使整个齿轮均匀硬化到齿根（见图2），具有质量稳定，可靠的优点，
交流磁力线满旋电流加热线围
变频电流
被加热物
作者简介：王能为（1977一），男，2006年毕业于武汉大学材料学专业，讲师
图1
爪
高频火装置示意