CN115679242A - A Processing Technology for Reducing the Deformation of Low Carbon Alloy Steel Gear - Google Patents

Abstract

The invention discloses a processing technology for reducing the deformation of a low-carbon alloy steel gear, which comprises the following steps of: (1) reserving machining allowance on the end face according to the depth of a carburized layer before carburization; (2) reserving machining allowance in the inner hole according to the depth of the carburized layer before carburization; (3) a high-temperature tempering process is added after carburizing and air cooling; (4) turning the end face and boring to remove a carburized layer; (5) in the quenching stage, the gear is vertically placed, and tempering is carried out in time after quenching; (6) turning the end face and digging a groove after tempering; (7) the artificial aging is added after the grooving process, the processing technology for reducing the deformation of the low-carbon alloy steel gear increases the structural strength of the low-carbon alloy steel gear, reduces the deformation of the low-carbon alloy steel gear caused by the structural change and the thermal stress change during quenching, removes the processing stress, reduces the deformation, and effectively ensures the quality of the low-carbon alloy steel gear.

Description

A Processing Technology for Reducing the Deformation of Low Carbon Alloy Steel Gear

technical field

The invention relates to the technical field of gear processing, in particular to a processing technology for reducing deformation of low-carbon alloy steel gears.

Background technique

Carburizing heat treatment refers to the infiltration of carbon atoms into the surface of the workpiece (low carbon steel or low carbon alloy steel) in the carburizing medium at a certain temperature, so that the carbon concentration on the surface changes, thereby obtaining a certain surface carbon content and a certain concentration gradient chemical heat treatment method. Carburized products obtain higher surface hardness, wear resistance, core toughness and higher contact fatigue and bending fatigue strength after quenching. In general, the gear processing process is: blank - machining - hobbing - carburizing, quenching, tempering - grinding - flaw detection - cleaning - storage. The structure of the intermediate gear is complicated. When the diameter and thickness of the intermediate gear are relatively large, it is easy to deform during the processing process, and the flatness is not easy to ensure. Therefore, there is a need for a process for reducing the deformation of low-carbon alloy steel gears, so as to reduce or avoid such phenomena.

At present, from the published materials, such as the authorized announcement number: CN201310562860.X "A processing method for preventing deformation of low-carbon steel gears" discloses a processing method for preventing deformation of low-carbon steel gears. Fill the through hole in the groove with materials during the heat treatment process, control the carbon potential and temperature in the heat treatment furnace, and avoid deformation during the heat treatment process. However, the defects of this invention are also obvious. The first filler is not pressed tightly, leaving gaps, etc., which will affect the deformation of the gear; the second filler may peel off during the heat treatment and affect the quenching quality; the third is time-consuming to prepare the filler and fill. Therefore, in order to solve the above technical problems, a processing technology for reducing the deformation of low-carbon alloy steel gears is needed.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the existing defects, provide a processing technology for reducing the deformation of low-carbon alloy steel gears, increase the structural strength of low-carbon alloy steel gears, and reduce the Deformation caused by tissue changes and thermal stress changes, removal of processing stress, and reduction of deformation can effectively solve the problems in the background technology.

In order to achieve the above object, the present invention provides the following technical solution: a processing technology for reducing deformation of low-carbon alloy steel gears, comprising the following steps:

① Reserve a machining allowance on the end face according to the depth of the carburized layer before carburizing;

②Reserve a machining allowance in the inner hole according to the depth of the carburized layer before carburizing;

③Add high temperature tempering process after carburizing and air cooling;

④ car end face, boring to remove carburized layer;

⑤ In the quenching stage, the gears are placed vertically and tempered in time after quenching;

⑥ After tempering, the end face and groove of the car;

⑦ Increase artificial aging after the grooving process.

As a preferred technical solution of the present invention, the size of the machining allowance reserved on the end face in the step ① is twice the depth of the infiltrated layer.

As a preferred technical solution of the present invention, the size of the machining allowance reserved for the inner hole in the step ② is twice the depth of the seepage layer.

As a preferred technical solution of the present invention, the temperature of high temperature tempering in step ③ is controlled at 640°C±10°C.

As a preferred technical solution of the present invention, the artificial aging control temperature in step ⑦ is 140°C±10°C.

Compared with the prior art, the beneficial effects of the present invention are: (1) the machining process for reducing the deformation of the low-carbon alloy steel gear ensures that the low-carbon alloy steel gear has a certain Structural strength, remove processing stress, reduce quenching deformation, increase high-temperature tempering and refine carbide after carburizing, reduce surface hardness of parts, facilitate removal of non-working surface carburized layer, and do not affect subsequent processing; (2) Utilizing the processing allowance reserved in the quenching stage, the structural strength of the low-carbon alloy steel gear is increased, and the deformation of the low-carbon alloy steel gear due to the structure change and thermal stress change during quenching is reduced, resulting in unqualified parts; (3) Adding artificial aging before grinding teeth removes the processing stress generated by the end face of the car and digging grooves, further reduces the deformation trend of low-carbon alloy steel gears, and solves the problem of low-carbon alloy steel gears, especially low-carbon alloys with relatively large diameters and thicknesses. Deformation problem of steel gears.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a technical solution: a processing technology for reducing deformation of low-carbon alloy steel gears, comprising the following steps:

① Before carburizing, reserve a machining allowance on the end face according to the depth of the carburizing layer, and the size of the machining allowance is twice the depth of the carburizing layer;

② Before carburizing, reserve a machining allowance in the inner hole according to the depth of the carburized layer, and the size of the machining allowance is twice the depth of the carburized layer;

③Add high-temperature tempering process after carburizing and air cooling, and the temperature is controlled at 640°C±10°C;

④ car end face, boring to remove carburized layer;

⑤ In the quenching stage, the gears are placed vertically and tempered in time after quenching;

⑥ After tempering, the end face and groove of the car;

⑦Add artificial aging after the trenching process, and control the temperature at 140°C±10°C.

Through the production verification of the intermediate gear shaft of the diesel engine, the flatness of the intermediate gear quenched by the above-mentioned processing technology is all within 0.2mm, and no distortion is found.

The invention rationally arranges the processing allowance and process sequence without using protective measures such as refractory mud, which not only ensures that the low-carbon alloy steel gear has a certain structural strength in the quenching stage, but also optimizes the processing process of the gear and removes the processing stress , Reduce deformation and ensure the quality of low carbon alloy steel gears.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (5)

1. A processing technology for reducing low carbon alloy steel gear deformation, is characterized in that: comprises the following steps: ① Reserve a machining allowance on the end face according to the depth of the carburized layer before carburizing; ②Reserve a machining allowance in the inner hole according to the depth of the carburized layer before carburizing; ③Add high temperature tempering process after carburizing and air cooling; ④ car end face, boring to remove carburized layer; ⑤ In the quenching stage, the gears are placed vertically and tempered in time after quenching; ⑥ After tempering, the end face and groove of the car; ⑦ Increase artificial aging after the grooving process. 2. A processing technology for reducing deformation of low-carbon alloy steel gears according to claim 1, characterized in that: the size of the machining allowance reserved for the end face in the step ① is twice the depth of the infiltrated layer. 3. A processing technology for reducing deformation of low-carbon alloy steel gears according to claim 1, characterized in that: the size of the machining allowance reserved for the inner hole in the step ② is twice the depth of the infiltrated layer. 4. A processing technique for reducing deformation of low-carbon alloy steel gears according to claim 1, characterized in that: the temperature of the high-temperature tempering in the step ③ is controlled at 640°C±10°C. 5. A processing technology for reducing deformation of low-carbon alloy steel gears according to claim 1, characterized in that: in step ⑦, the artificial aging control temperature is 140°C±10°C.