Manufacturing process of tool screwdriver
By using an endothermic controllable atmosphere device and molten salt heat treatment in the manufacturing process of tool driver, the crystal structure of steel is transformed, combined with tempering and surface treatment, the deformation and stress problems of tool driver in the heat treatment are solved, and the problem of it is improved. Quality and performance to prevent fragility and breakage.
Patent Information
- Application Number
- CN202310873321.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-17
- Publication Date
- 2025-01-17
AI Technical Summary
Existing tool drivers are prone to deform during heat treatment, resulting in incorrect shape and size, internal stresses lead to instability and faster wear, excessive or improper heat treatment can make the material fragile and increase the risk of breakage or damage.
Heat treatment is carried out using an endothermic controllable atmosphere device, and the crystal structure of iron is transformed into molten salt, so that the crystal structure of the steel is transformed from austenite to a mixed structure of martensite and bainite, and tempered, Cleaning and surface treatments, including sandblasting and phosphating, are finalized for testing such as torque, hardness and fatigue.
Ensure the quality and performance of tool drivers, avoid deformation and stress problems, improve wear resistance and service life, and prevent fragility and risk of fracture.
Smart Images
Figure CN119320859A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a tool screwdriver, in particular to a manufacturing process of the tool screwdriver. Background Art
[0002] Tool screwdrivers are a common metal product that is often used in machining and maintenance work to remove and install various threaded parts. The manufacturing process of tool screwdrivers usually requires heat treatment to improve hardness and wear resistance, thereby increasing service life.
[0003] However, existing tool drivers are prone to deformation during the heat treatment process, resulting in incorrect shapes and sizes. In addition, the tool driver may generate internal stress after heat treatment, resulting in instability or faster wear when using the tool driver. In addition, excessive heat treatment or improper heat treatment may cause the material of the tool driver to become brittle, causing the tool driver to be easily broken or damaged. Summary of the invention
[0004] An object of the present invention is to provide a manufacturing process for a tool driver to ensure the quality and performance of the tool driver.
[0005] In order to achieve the above-mentioned purpose, the present invention is a manufacturing process for a tool screwdriver, the steps of which include a) providing steel and processing it into a screwdriver prototype; b) providing a heating furnace and molten salt, placing the screwdriver prototype in the heating furnace and molten salt for heat treatment; c) increasing the temperature of the heating furnace and placing the screwdriver prototype in the molten salt to undergo a crystal structure transformation process of iron; d) cleaning the screwdriver prototype; e) tempering the screwdriver prototype to transform the crystal structure of the steel from austenite to a mixed structure of martensite and bainite; and f) surface treating the screwdriver prototype to form a tool screwdriver.
[0006] In one embodiment of the present invention, the processing operation includes: a1) cutting and machining the steel material to cut out a predetermined length of the screwdriver prototype; and a2) turning one end of the screwdriver prototype to form a predetermined specification.
[0007] In one embodiment of the present invention, the heating furnace is an endothermic controlled atmosphere device, and the temperature of the endothermic controlled atmosphere device is increased to 875°C.
[0008] In one embodiment of the present invention, the endothermic controlled atmosphere device uses an appropriate amount of enriched propane as the protective gas.
[0009] In one embodiment of the present invention, the molten salt is composed of sodium nitrite and potassium nitrate, and the temperature of the screwdriver prototype being placed in the molten salt is 235° C. and the operation time is 4 hours.
[0010] In one embodiment of the present invention, the mixed structure includes more than 60 weight % of martensite, more than 15 weight % of bainite, more than 10 weight % of retained austenite and more than 1 weight % of unmelted carbides.
[0011] In one embodiment of the present invention, the cleaning operation is performed in water at 60°C.
[0012] In one embodiment of the present invention, the tempering temperature is 280° C. and the tempering time is 6 hours.
[0013] In one embodiment of the present invention, the surface treatment operation includes sandblasting and phosphating.
[0014] In one embodiment of the present invention, the manufacturing process of the tool driver further includes a testing operation, and the testing operation includes performing a torque test, a hardness test, and a fatigue test on the tool driver.
[0015] Compared with the prior art, the manufacturing process of the tool driver of the present invention utilizes an endothermic controlled atmosphere device for heat treatment, and places molten salt to transform the crystal structure of iron, so that the crystal structure of iron is transformed from austenite to a mixed structure of martensite and bainite, and the mixed structure contains more than 60 weight percent of martensite, more than 15 weight percent of bainite, more than 10 weight percent of retained austenite and more than 1 weight percent of unmelted carbide, thereby ensuring the quality and performance of the tool driver. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 The figure is a schematic diagram of the manufacturing process of the tool screwdriver of the present invention.
[0017] Figure 2 It is a plan view of a screwdriver prototype of the present invention.
[0018] In the figure: 1: Screwdriver prototype; L: predetermined length; D: size of opposite sides; Steps: a~f. DETAILED DESCRIPTION
[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.
[0020] Please refer to Figure 1 and Figure 2, which is a schematic diagram of the manufacturing process of the tool screwdriver of the present invention and a planar schematic diagram of the screwdriver prototype. The present invention is a manufacturing process of a tool screwdriver, comprising the following steps. a) providing a steel material, and making a screwdriver prototype 1 through a processing operation. b) providing a heating furnace and a molten salt, placing the screwdriver prototype 1 into the heating furnace and the molten salt for a heat treatment operation. c) increasing the temperature of the heating furnace, and placing the screwdriver prototype 1 into the molten salt for a crystal structure transformation process of iron. d) performing a cleaning operation on the screwdriver prototype 1. e) performing a tempering operation on the screwdriver prototype 1, and the crystal structure of the steel material is transformed from austenite to a mixed structure of martensite and bainite. f) performing a surface treatment operation on the screwdriver prototype 1, and forming a tool screwdriver.
[0021] Specifically, the processing operation of step a) includes: a1) cutting and machining the steel material to cut out a predetermined length L of the screwdriver prototype 1; and a2) turning one end of the screwdriver prototype 1 to form a predetermined specification.
[0022] In this embodiment, the raw material (steel) of the screwdriver prototype 1 is a hexagonal steel with a diameter of 1 / 4 inch, and its opposite side dimension D is 6.29 mm to 6.35 mm. In addition, the predetermined length L is 65 mm. The cutting edge of the screwdriver prototype 1 is milled to PH2 specification, but it is not limited to this. In actual implementation, the external dimensions of the screwdriver prototype 1 can be processed according to actual use requirements.
[0023] Furthermore, in step b), the heating furnace is an endothermic controlled atmosphere device, and the temperature of the endothermic controlled atmosphere device is increased to 875°C. In addition, the endothermic controlled atmosphere device uses an appropriate amount of enriched propane as a protective gas. Furthermore, the molten salt is composed of sodium nitrite and potassium nitrate, and the temperature of the screwdriver prototype 1 placed in the molten salt is 235°C, and the isothermal structural transformation is performed for 4 hours.
[0024] It should be noted that in step c), the crystal structure transformation process of iron is defined as the transformation of the crystal structure of the raw material (iron) from austenite (Austenite) to a mixed structure of martensite (Martensite) and bainite (Bainite), wherein the mixed structure contains more than 60% by weight of martensite, more than 15% by weight of bainite, more than 10% by weight of retained austenite and more than 1% by weight of unmelted carbides.
[0025] It should also be noted that heating the steel in an endothermic controlled atmosphere device can avoid surface oxidation or decarburization.
[0026] Furthermore, in step d), the cleaning operation is performed in water at 60°C. In step e), the tempering operation temperature is 280°C and the operation time is 6 hours, so as to eliminate the structural transformation stress and thermal stress during the quenching process. In addition, in step f), the surface treatment operation includes a sandblasting treatment and a phosphating treatment.
[0027] In one embodiment of the present invention, the manufacturing process of the tool driver further includes a testing operation, and the testing operation includes performing a torque test, a hardness test and a fatigue test on the tool driver.
[0028] Specifically, the tool screwdriver must pass the aforementioned testing operations. For example, the breaking torque value of the torque test is 190 to 240 kg / cm. In addition, when the tool screwdriver undergoes a hardness test, the hardness value of the middle surface is HRC60 to 62.5 degrees, and the hardness value of the working end is HRC61 to 63.5 degrees. In addition, the fatigue test of the tool screwdriver is to withstand a load of 10.33 N / m for 100,000 times. It should be noted that the breaking rotation angle of the tool screwdriver is between 180 and 360 degrees.
[0029] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.
Claims
1. A manufacturing process for a tool screwdriver, characterized in that: The following steps are involved: a) providing a steel material and processing it into a prototype; b) providing a heating furnace and a molten salt, placing the screwdriver prototype into the heating furnace and the molten salt for a heat treatment operation; c) raising the temperature of the heating furnace and placing the screwdriver prototype into the molten salt; d) performing a cleaning operation on the screwdriver prototype; e) performing a tempering operation on the screwdriver prototype, wherein the crystal structure of the steel material is transformed from austenite to a mixed structure of martensite and bainite; and f) performing a surface treatment operation on the screwdriver prototype to form a tool screwdriver.
2. The manufacturing process of the tool driver according to claim 1, characterized in that: The processing includes: a1) cutting and machining the steel material to cut out a predetermined length of the screwdriver prototype; and a2) turning one end of the screwdriver prototype to form a predetermined specification.
3. The manufacturing process of the tool driver according to claim 1, characterized in that: The heating furnace is an endothermic controlled atmosphere device, and the temperature of the endothermic controlled atmosphere device is increased to 875°C.
4. The manufacturing process of the tool driver according to claim 3, characterized in that: The endothermic controlled atmosphere device uses a proper amount of enriched propane as the protective gas.
5. The manufacturing process of the tool driver according to claim 1, characterized in that: The molten salt is composed of sodium nitrite and potassium nitrate. The temperature of the screwdriver prototype placed in the molten salt is 235° C. and the operation time is 4 hours.
6. The manufacturing process of the tool driver according to claim 2, characterized in that: The mixed structure contains more than 60 weight percent of martensite, more than 15 weight percent of bainite, more than 10 weight percent of retained austenite and more than 1 weight percent of unmelted carbide.
7. The manufacturing process of the tool driver according to claim 1, characterized in that: The cleaning operation was carried out in water at 60°C.
8. The manufacturing process of the tool driver according to claim 1, characterized in that: The tempering temperature is 280°C and the tempering time is 6 hours.
9. The manufacturing process of the tool driver according to claim 1, characterized in that: The surface treatment operation includes a sandblasting process and a phosphating process.
10. The manufacturing process of the tool driver according to claim 1, characterized in that: The invention further comprises a testing operation, wherein the testing operation comprises performing a torque test, a hardness test and a fatigue test on the tool screwdriver.