锉刀是一种多刃的切削工具，主要用于锉削硬度为18~58HRC范围
内的金属材料。工作中承受强烈磨损和弯曲变形以及一定的冲
击。因此，要求锉刀具有较好耐磨性的同时，还需要具有一定的
抗弯强度和韧性。
File is a multi-edged cutting tool, mainly used to file
hardness of 18 ~ 58 HRC range of metal materials. The
work is subjected to strong wear and bending deformation
and certain impact. Therefore, it is required that the
file tools have better wear resistance, but also a
certain flexural strength and toughness. (1)锉刀的失效分
析 同种材料制作的优质锉刀使用过程的失效形式是磨损；质量不
佳的锉刀往往是早期断齿和崩刃。失效分析表明，两者仅仅是组
织结构的差异，即碳化物形态和基体组织形态不同。
(1) Failure Analysis of Files The failure mode of high-
quality files made of the same material is wear and tear,
and the poor-quality files are often early broken teeth
and broken edges. Failure analysis shows that the two are
only differences in microstructure, i. e. carbide
morphology and matrix morphology.(2)热处理工艺性分析 由于T12A钢是过共析钢，脆性较大。常规
热处理一般是以获得细小碳化物为目的，改善其韧性并获得强韧
化效果。然而，对锉刀而言要得到良好的锉削性能，认为在组织
中保持一定数量的大颗粒碳化物是很有效的方法。同时，为了保
持良好的韧性，热处理后基体应是低碳马氏体组织并将碳化物棱
角钝化。
(2) heat treatment process analysis, because T12A steel
is hypereutectoid steel, brittleness is larger.
Conventional heat treatment is usually to obtain fine
carbides for the purpose of improving its toughness and
toughening effect. However, in order to obtain good file
performance, it is considered that it is an effective
method to keep a certain amount of large particles of
carbide in the microstructure. At the same time, in order
to maintain good toughness, the matrix after heat
treatment should be low carbon martensite structure and
carbide edge passivation.
(3)锉刀的热处理工艺设计
(3) heat treatment process design for file
1)预备热处理：采用图5-1所示的两段等温球化退火工艺，旨在改
变锉刀的原始组织状态。首先加热到比Accm(820℃)稍高的
840~850℃，经适当保温，使组织中仅保留为数不多的碳化物，且
奥氏体组织不均匀。然后，进入第一阶段球化退火，组织中不均
匀奥氏体的高浓度碳偏析区和未溶碳化物成为大颗粒碳化物长大
的核心。同时，在周边组织中碳浓度降低，为淬火后获得低碳马
氏体做好组织准备。在进入第二阶段球化退火时，即在Ac1以下等
温，碳化物进一步扩散、析出、聚集球化，使大颗粒碳化物进一
步长大，并新生许多弥散分布的小颗粒碳化物。如此，一定数量
的大颗粒碳化物和大量的珠光体为最终热处理奠定了良好基础。
1) Pre-heat treatment: The two-stage isothermal
spheroidizing annealing process shown in Fig. 5-1 was
used to change the original microstructure of the file.
Firstly, it is heated to 840 ~ 850 C higher than Accm
(820 C). After proper heat preservation, only a few
carbides are retained in the microstructure, and the
austenite structure is inhomogeneous. Then, in the first
stage of spheroidizing annealing, the high concentration
carbon segregation zone and the undissolved carbide of
the inhomogeneous austenite become the core of the growth
of large carbide particles. At the same time, the carbon
concentration in the surrounding tissues is reduced, so
as to prepare for low carbon martensite after quenching.
In the second stage of spheroidizing annealing, that is,
under the isothermal temperature of Ac1, carbides further
diffuse, precipitate, aggregate and spheroidize, so that
large particles of carbides grow further, and many small
particles of dispersed carbides are generated. Thus, a
certain amount of large particle carbide and a large
number of pearlite lay a good foundation for the final
heat treatment.
2)最终热处理：采用快速加热短时保温的热处理工艺。由于实际
刃部加热温度较低，加热时间较短，碳化物大小不均，溶解速度
不同，故得到成分极不均的奥氏体和一定数量的碳化物，淬火后
组织性能良好。
2) final heat treatment: heat treatment process with
quick heating and short time insulation. Due to the lower
heating temperature, shorter heating time, uneven size of
carbide and different dissolution rate, a certain amount
of carbide and austenite with extremely uneven
composition are obtained, and the microstructure and
properties are good after quenching.
(4)处理结果 组织为一定数量的低碳马氏体+较多的隐针马氏体
+棱角钝化且大小不均碳化物；断口形貌为大量浅韧窝和撕裂棱；
锉刀使用寿命达到50万次的较高水平。
(4) The results show that the microstructure is low-
carbon martensite + more crypto-acicular martensite +
edge passivation and uneven size carbide; the fracture
morphology is a large number of shallow dimples and
tearing edges; the service life of the file reaches a
high level of 500,000 times.
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