阅读说明：本技术 一种回转驱动的表面软氮化化学热处理强化方法 (Rotation-driven surface soft nitriding chemical heat treatment strengthening method ) 是由 罗贤 尚利 徐正茂 金开瑞 于 2020-05-07 设计创作，主要内容包括：本发明公开了一种回转驱动表面软氮化化学热处理的实验方法技术领域的一种回转驱动的表面软氮化化学热处理强化方法,包括预处理待软氮化的回转驱动,所述预处理待软氮化的回转驱动的下一步为排出炉内空气,所述排出炉内空气的下一步为设定工艺参数保温,所述设定工艺参数保温的下一步为出炉油冷,所述出炉油冷的下一步为软氮化处理完成；原理是使共渗介质在软氮化温度下发生热分解反应,产生活性极强的碳、氮原子；这些原子被回转驱动表面吸收,并通过扩散逐步渗入工件表层,从而获得以渗氮为主、渗碳为辅的氮碳共渗层；表面最外层的化合物层和次层的扩散层组织能显著提高回转驱动的表面硬度、耐磨性及抗疲劳强度等,从而满足工件的使用需求。(The invention discloses a rotation-driven surface tufftride chemical heat treatment strengthening method in the technical field of rotation-driven surface tufftride chemical heat treatment experimental methods, which comprises the steps of preprocessing the rotation drive to be tufftride, discharging air in a furnace in the next step of the rotation drive to be preprocessed, setting process parameters for heat preservation in the next step of the discharged air in the furnace, discharging oil for cooling in the next step of the set process parameters for heat preservation, and finishing tufftride treatment in the next step of the discharged oil for cooling; the principle is that the co-permeation medium generates thermal decomposition reaction at the tufftriding temperature to generate carbon and nitrogen atoms with extremely strong activity; the atoms are absorbed by the rotary driving surface and gradually permeate into the surface layer of the workpiece through diffusion, so that a nitrocarburizing layer which takes nitriding as main and carburizing as auxiliary is obtained; the compound layer on the outermost layer of the surface and the diffusion layer structure on the sublayer can obviously improve the surface hardness, the wear resistance, the fatigue resistance and the like of the rotary drive, thereby meeting the use requirements of workpieces.)

1. A rotation-driven surface soft nitriding chemical heat treatment strengthening method is characterized by comprising the following steps: the method comprises the steps of preprocessing the rotary drive to be subjected to soft nitriding, discharging air in the furnace in the next step of the rotary drive to be subjected to the soft nitriding, setting process parameter heat preservation in the next step of the air in the furnace, discharging oil cooling in the next step of the process parameter heat preservation, and finishing the soft nitriding in the next step of the discharging oil cooling.

2. The method of claim 1, wherein the step of performing the soft nitriding chemical heat treatment on the surface comprises the steps of: the strengthening technology comprises the following steps:

step 1: the rotary driving sample is made of 42CrMo steel, and the blank is subjected to thermal refining in advance to obtain a uniform tempered sorbite structure;

step 2: cleaning the surface of the sample to be treated by using gasoline, alkaline water and clear water in sequence for subsequent tufftride treatment;

and step 3: setting the furnace temperature, placing the sample to be treated in an improved well-type nitriding furnace after the furnace temperature is raised to the set temperature, and sealing a furnace cover; introducing ammonia gas, dripping ethanol, increasing the flow of the ammonia gas and the dripping amount of the ethanol, completely opening an exhaust valve, and discharging air in the furnace;

and 4, step 4: when the air in the furnace is exhausted to be below 5 percent, the furnace temperature is raised to the tufftride temperature again, the ammonia alcohol supply and the ratio are controlled, the ammonia decomposition rate is adjusted, a good, stable and continuously updated tufftride atmosphere can be formed in the furnace, and the heat preservation time is calculated at the moment;

and 5: stopping dripping ethanol after the heat preservation is finished, and introducing a small amount of ammonia gas to a sample to be discharged;

step 6: and (4) quickly cooling the sample by oil after the sample is taken out of the furnace, so that the sample can obtain higher seepage layer hardness.

3. The method as claimed in claim 2, wherein the step of performing the soft nitriding chemical heat treatment on the surface of the rotary drive comprises the steps of: the furnace temperature in step 3 is set to 570 ± 10 ℃.

4. The method as claimed in claim 2, wherein the step of performing the soft nitriding chemical heat treatment on the surface of the rotary drive comprises the steps of: in the step 3, the flow rate of the ethanol is 80-90 drops/min, and the flow rate of the ammonia gas is 500-550L/h.

5. The method as claimed in claim 2, wherein the step of performing the soft nitriding chemical heat treatment on the surface of the rotary drive comprises the steps of: and the opening time of the exhaust valve in the step 3 is 30 min.

6. The method as claimed in claim 2, wherein the step of performing the soft nitriding chemical heat treatment on the surface of the rotary drive comprises the steps of: in the step 4, the flow rate of ethanol is 70-80 drops/min, the flow rate of ammonia gas is 450-500L/h, and the decomposition rate of ammonia gas is 30-40%.

Technical Field

The invention relates to an experimental method for rotary driving surface tufftride chemical heat treatment, in particular to a rotary driving surface tufftride chemical heat treatment strengthening method.

Background

The material surface chemical heat treatment refers to a heat treatment process for changing the surface components, tissues and appearances of the materials to be treated by methods such as atomic diffusion, chemical reaction and the like so as to obtain the required properties on the material surface. The rotary drive is used as a power transmission part and continuously works under the environment of high load and high rotating speed for a long time, and the wear resistance and fatigue resistance of the surface of the material are critical to the normal use of a workpiece, so that the surface strengthening treatment is needed, and the chemical heat treatment is a common surface strengthening process. The surface chemical heat treatment process is that the part is put into a proper medium for heating and heat preservation, so that one or more elements penetrate into the surface layer of the part to change the chemical components and the tissue structure of the part, such as carburization, nitridation, boronization and the like;

nitriding methods are currently widely used in the industry to treat rotary drive surfaces. The nitriding process was performed as follows: firstly, cleaning the surface of the rotary drive before nitriding; then the processed rotation is driven into the nitriding furnace, the sealing cover is heated, the furnace temperature is raised to the nitriding temperature (between 520 ℃ and 570 ℃) after the air in the furnace is removed. The surface layer with high strength and high wear resistance can be obtained by rotation driving after nitriding treatment, but the method has long production period, heat preservation needs to be carried out for 15-30 hours according to the thickness required by nitriding, and the production efficiency is low. According to the invention, through low-temperature nitrocarburizing, the soft nitriding treatment is carried out on the surface of the rotary driving, so that the surface hardness, the wear resistance and the fatigue resistance of the material are improved, the processing time can be effectively shortened, and the production cost is reduced.

Disclosure of Invention

The invention aims to provide a rotary driving surface soft nitriding chemical heat treatment strengthening method, aiming at solving the problems of long nitriding treatment time and large surface layer brittleness of a rotary driving part and providing an experimental method for carrying out surface heat treatment strengthening on the rotary driving by adopting a soft nitriding treatment process in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme: a rotation-driven surface tufftride chemical heat treatment strengthening method comprises preprocessing rotation drive to be tufftride, wherein the next step of the rotation drive to be preprocessed is discharging air in a furnace, the next step of discharging the air in the furnace is setting process parameters for heat preservation, the next step of setting the process parameters for heat preservation is discharging oil cooling, and the next step of discharging the oil cooling is completing tufftride treatment.

Preferably, the furnace temperature in step 3 is set to 570 ± 10 ℃.

Preferably, the flow rate of the ethanol in the step 3 is 80-90 drops/min, and the flow rate of the ammonia gas is 500-550L/h.

Preferably, the opening time of the exhaust valve in the step 3 is 30 min.

Preferably, in the step 4, the flow rate of ethanol is 70-80 drops/min, the flow rate of ammonia gas is 450-500L/h, and the decomposition rate of ammonia gas is 30-40%.

A rotation-driven surface soft nitriding chemical heat treatment strengthening method comprises the following steps:

step 1: the rotary driving sample is made of 42CrMo steel, and the blank is subjected to thermal refining in advance to obtain a uniform tempered sorbite structure;

step 2: cleaning the surface of the sample to be treated by using gasoline, alkaline water and clear water in sequence for subsequent tufftride treatment;

and step 3: setting the furnace temperature, placing the sample to be treated in an improved well-type nitriding furnace after the furnace temperature is raised to the set temperature, and sealing a furnace cover; introducing ammonia gas, dripping ethanol, increasing the flow of the ammonia gas and the dripping amount of the ethanol, completely opening an exhaust valve, and discharging air in the furnace;

and 4, step 4: when the air in the furnace is exhausted to be below 5 percent, the furnace temperature is raised to the tufftride temperature again, the ammonia alcohol supply and the ratio are controlled, the ammonia decomposition rate is adjusted, a good, stable and continuously updated tufftride atmosphere can be formed in the furnace, and the heat preservation time is calculated at the moment;

and 5: stopping dripping ethanol after the heat preservation is finished, and introducing a small amount of ammonia gas to a sample to be discharged;

step 6: and (4) quickly cooling the sample by oil after the sample is taken out of the furnace, so that the sample can obtain higher seepage layer hardness.

Compared with the prior art, the invention has the beneficial effects that:

the method adopts a gas tufftride method to treat the surface of the rotary drive, the ethanol is dripped by ammonia gas as a co-permeation medium, and the principle is that the co-permeation medium generates thermal decomposition reaction at tufftride temperature to generate carbon and nitrogen atoms with extremely strong activity; the atoms are absorbed by the rotary driving surface and gradually permeate into the surface layer of the workpiece through diffusion, so that a nitrocarburizing layer which takes nitriding as main and carburizing as auxiliary is obtained; after the workpiece is subjected to soft nitriding treatment, the compound layer on the outermost layer of the surface and the diffusion layer structure on the sublayer can obviously improve the surface hardness, the wear resistance, the fatigue resistance and the like of the rotary drive, so that the use requirement of the workpiece is met.

1. The microhardness of the surface of the rotary drive after being treated by the soft nitriding method can reach more than 700HV, the thickness of a permeable layer can reach about 0.4mm (shown in figure I), the hardness is similar to that after being treated by the nitriding method, and the permeable layer has certain toughness because the surface layer has no brittle phase after being treated by the soft nitriding method, so that the use requirement of the rotary drive is met;

2. compared with nitriding treatment, the soft nitriding treatment greatly shortens the production period and greatly saves the production cost;

3. the gas soft nitriding method adopted by the invention is simple and convenient to operate, easy to realize mechanization and automation, stable in treatment quality, and the process is not limited by steel grades.

Drawings

FIG. 1 is a schematic flow chart of an embodiment of the present invention;

FIG. 2 is a process diagram of an embodiment of the present invention;

FIG. 3 is a graph showing the hardness distribution of the surface layer after the surface soft-nitriding of the rotary drive according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides a technical solution: a rotation-driven surface tufftride chemical heat treatment strengthening method comprises preprocessing rotation drive to be tufftride, wherein the next step of the rotation drive to be preprocessed is discharging air in a furnace, the next step of discharging the air in the furnace is setting process parameters for heat preservation, the next step of setting the process parameters for heat preservation is discharging oil cooling, and the next step of discharging the oil cooling is completing tufftride treatment.

Wherein the furnace temperature in the step 3 is set to 570 +/-10 ℃; in the step 3, the flow rate of ethanol is 80-90 drops/min, and the flow rate of ammonia gas is 500-550L/h; the opening time of the exhaust valve in the step 3 is 30 min; in the step 4, the flow rate of ethanol is 70-80 drops/min, the flow rate of ammonia gas is 450-500L/h, and the decomposition rate of ammonia gas is 30-40%.