HOT INFORMATION / More
1
2018 - 09 - 22
1) high strength: in order to improve the spring's ability to resist fatigue failure and relaxation, the spring material should have a high yield strength and elastic limit, and in particular, a high ratio of strength to strength.In general, the elastic limit of the material is directly proportional to the yield strength, so the spring design and the manufacturer always want the material to have a high yield strength.The tensile strength and yield strength of the spring material are close, for example, about 90% of the carbon steel wire of cold drawn is about: since the tensile strength is eas...
2
2018 - 09 - 22
Spring is a kind of elastic element widely used in the mechanical and electronic industries. Spring can produce greater elastic deformation when loaded, and convert mechanical work or kinetic energy into deformation energy. After unloading, the deformation of spring disappears and returns to its original state, and the deformation energy is transformed into mechanical work or kinetic energy.The ratio of load and deformation of the spring is called spring stiffness.  There are many kinds of springs. They are used in various fields. According to the deformation condition, they can be divide...
3
2018 - 09 - 21
compression spring is under axial pressure of the spiral spring, it is used in the data section for more rounded, useful also rectangle and multi-strand steel rolled a travelling, spring is usually pitch, such as the shape of the compression spring are: cylindrical, conical, convex and concave and a small amount of noncircular, compression spring there is a certain gap between circle and circle, when under external load spring contraction deformation, deformation energy storage.The tension spring is a spiral spring that bears the axial tension.When there is no load, the stretch spring is usual...
4
2018 - 09 - 21
Compression springs are frequently seen and used in daily life. The main principle of compression springs is to provide a hand to the machine and drive it to work.The compression spring has a certain damping capacity, because the product's elastic force is not a fixed value, so every time it is used, there will be a return force, and the force is not a fixed size, which to some extent has the ability to slow down the vibration.As an example, now the car is installed above a compression spring, you will find when driving, its speed is greatly improved, and the movement process there is no sound...
5
2018 - 09 - 20
The corrosion of spring can be divided into chemical corrosion and electrochemical corrosion according to the type of reaction.They are the result of changes in the metal atoms on the surface of the spring or the loss of electrons to an ionic state.If the metal on the surface of the spring simply reacts with the surrounding medium, and the spring causes corrosion, it is called chemical corrosion.For example, the spring is oxidized in the particularly dry atmosphere to form an oxidation film, and the spring is chemically changed with the liquid or impurity in the non-electrolyte liquid, which i...
6
2018 - 09 - 20
The purpose of mold spring is to take off material, press material, the strength of the spring, which is related to whether the mold production is smooth, whether the product is qualified.Spring force is small, may cause the product to be out of shape, the mold does not take off the material, the product is bad to take out from the mold inside, the belt material, the knife edge, punch easy to wear and so on each kind of question.Mold spring according to different production times, compression amount selected, the larger the spring life, the shorter die life, of course, the broken spring can be...
7
2018 - 09 - 19
Spring steel wire will generate residual stress during the process of cold drawing and oil quenching and heat treatment. Moreover, spring wire is formed during the process of manufacturing and shot peening is conducted.High frequency quenching, carburizing, nitrification, etc. are used as surface hardening treatment. As a result of these treatments, residual stress will be generated in the material.The qualitative and quantitative analysis of the residual stress of the material will be an important factor to improve the fatigue properties of the spring.Residual stress of the spring is usually ...
8
2018 - 09 - 19
Spring machine is now in the production of spring necessary equipment, due to the abundant of spring and the increase of precision is also more and more high to the requirement of spring machine, the spring machine maintenance is particularly important at ordinary times, and the main factors affecting the service life of spring machine has two, one is the operator of whether scientific and standardized operation, another is reasonable in daily maintenance.After using the spring machine for a period of time, the efficiency of the machine will be significantly reduced, affecting the efficiency o...
9
2018 - 09 - 25
Nowadays, with the development of science and technology, spring has become a very important hardware accessory in our life. Different products use different springs, and the longest used springs can be roughly divided into: pull spring, twist spring, press spring, disc spring and plate spring.The following features of a very practical tension spring:Many different products or hooks are used to guarantee the source of the tension of the tension spring. The tension spring works in the opposite way to the compression spring. The tension spring works in the opposite way when stretching or pulling...
NEW INFORMATION / More
1
2018 - 09 - 27
In the actual work, we often encounter that the spring cannot push the moving object to the set position, that is to say, the length of the spring's computational freedom becomes shorter.The main reason is that there is no initial compression, that is, a spring is made into a spring, which is compressed to its compression height or to its compression height (if necessary) with a greater force, and cannot be restored to its original free length upon release.Its shortened quantity is called "initial compression quantity".After repeating 3-6 times of compression, the length is no longer...
2
2018 - 09 - 26
The selection of spring material shall be determined according to the properties of the spring bearing load, stress state, stress size, working temperature, environmental medium, service life, requirements for conducting and magnetic conductivity, technical performance, material source and price, etc.When determining the shape and size of the material section, the series sizes specified in the national standards and ministerial standards should be selected first, and non-standard series of materials should be avoided as far as possible.Medium and small-sized springs, especially spiral-tension ...
3
2018 - 09 - 26
For a long time, the shape and performance of the extension spring will change. If the extension spring is always in a certain situation, it may change its quality due to external conditions.Generally, there are the following situations:I. wear of extension spring :Wear can be divided into abrasive, fatigue and corrosion wear fracture.Ii. Brittle fractureThe majority of spring break belongs to brittle fracture.Plastic fracture is possible only when the working temperature is high.In engineering, fatigue fracture, stress corrosion fracture and hydrogen embrittlement fracture are called brittle ...
4
2018 - 09 - 25
Torsion spring is a mechanical force storage structure, mainly used in ancient crossbow guns and other crossbow.The torsion spring accumulates the force through the twist or rotation of the elastic material with a relatively soft and pliable material, and makes use of it so that the projectile has certain mechanical energy.The modern torsion spring torsion bar is made of excellent elastic steel, and the form is also changed a lot, including the wire on the inner surface of the mechanical watch, the power spring in the toy gyroscope gun, as well as the torsion bar in the tank and car.Small...
5
2018 - 09 - 25
Nowadays, with the development of science and technology, spring has become a very important hardware accessory in our life. Different products use different springs, and the longest used springs can be roughly divided into: pull spring, twist spring, press spring, disc spring and plate spring.The following features of a very practical tension spring:Many different products or hooks are used to guarantee the source of the tension of the tension spring. The tension spring works in the opposite way to the compression spring. The tension spring works in the opposite way when stretching or pulling...
6
2018 - 09 - 22
1) high strength: in order to improve the spring's ability to resist fatigue failure and relaxation, the spring material should have a high yield strength and elastic limit, and in particular, a high ratio of strength to strength.In general, the elastic limit of the material is directly proportional to the yield strength, so the spring design and the manufacturer always want the material to have a high yield strength.The tensile strength and yield strength of the spring material are close, for example, about 90% of the carbon steel wire of cold drawn is about: since the tensile strength is eas...
7
2018 - 09 - 22
Spring is a kind of elastic element widely used in the mechanical and electronic industries. Spring can produce greater elastic deformation when loaded, and convert mechanical work or kinetic energy into deformation energy. After unloading, the deformation of spring disappears and returns to its original state, and the deformation energy is transformed into mechanical work or kinetic energy.The ratio of load and deformation of the spring is called spring stiffness.  There are many kinds of springs. They are used in various fields. According to the deformation condition, they can be divide...
8
2018 - 09 - 27
In order to make it convenient for customers to buy and custom spring, some brief introduction about spring and specification parameters are summarized as follows:The common spring can be classified as: stretching spiral spring, compression spiral spring and torsion spiral spring.Among them, stretch and compression springs are mostly produced in quantity, with complicated specifications but suitable for slight modifications. If a small amount of springs is needed and the characteristics of springs are not critical, they can be purchased easily in the market with a higher unit price.The users o...
9
2018 - 09 - 28
The diameter of wire wound by automatic spring machine is 0.2-3mm, and the adjustment process is as follows:1. Calibrate the feeding roller and winch to fit the diameter of steel wire and install the pitch wedge and cutting knife.2. Insert the steel wire into the spring machine and press the pressure plate and feeding roller.3. Adjust the distance of winding xiao zi, control the diameter of spring, and adjust the pitch wedge and xiao zi Angle to control the spring pitch and parallel head.4. Install an appropriate cutter, adjust the feeding CAM according to the spring expansion length, cut off ...
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Hardness testing method for tempering heat treatment

日期: 2018-09-17
浏览次数: 1
Daisy

Hard inspection method for chemical heat treatment and surface quenching and tempering

Surface heat treatment is divided into two categories, one is chemical heat treatment and the other is surface quenching and tempering heat treatment. The hardness test method is as follows:

1. Chemical heat treatment

Chemical heat treatment is to make the workpiece surface infiltrate one or several chemical elements of the atom, thereby changing the workpiece surface chemical composition, organization and performance.After quenching and tempering, the surface of the workpiece has high hardness, wear resistance and contact fatigue strength, and the core of the workpiece has high toughness.

The main technical parameters of chemical heat treatment workpiece are the depth of hardened layer and surface hardness.The depth of the hardened layer is still determined by a vickers hardness tester.Detect the distance from the surface of the workpiece to the point where the hardness is reduced to 50HRC.This is the effective depth of hardening chemical heat treatment of workpiece surface hardness testing and surface heat treatment quenching hardness testing, can use vickers hardness tester, surface rockwell hardness tester or rockwell hardness tester to test, only the thickness of nitriding thick thin, generally not more than 0.7 mm, is no longer using rockwell hardness tester.

2. Surface quenching and tempering heat treatment

Surface quenching and tempering heat treatment is usually performed by induction heating or flame heating.The main technical parameters are surface hardness, local hardness and effective depth of hardened layer.The hardness test can be done by vickers hardness tester, or by rockwell hardness tester or surface rockwell hardness tester.The selection of test force (scale) is related to effective hardening depth and workpiece surface hardness.There are three types of durometer involved here.

The vickers hardness tester is an important means to test the surface hardness of the heat-treated workpiece. It can choose the test force of 0.5 ~ 100kg to test the surface hardening layer of the workpiece thin to 0.05mm thick. It has the highest accuracy and can distinguish the slight difference of the surface hardness of the heat-treated workpiece.In addition, the effective depth of the hardening layer is also detected by the vickers hardness tester, so it is necessary to have a vickers hardness tester for the units that conduct surface heat treatment or use a large number of surface heat treatment workpieces.

The surface rockwell hardness tester is also very suitable for testing the hardness of surface hardened workpiece.Various surface hardened workpieces whose effective hardening depth exceeds 0.1mm can be tested.Although the precision of the surface rockwell hardness tester is not as high as that of the vickers hardness tester, it has been able to meet the requirements as a means of quality management and qualified inspection in the heat treatment plant.In addition, it is easy to operate, easy to use, low price, rapid measurement and direct reading of hardness values. By using the surface rockwell hardness tester, it can be used to quickly and nondestructive testing of the surface heat treatment workpieces.This is of great significance to metal processing and machinery manufacturing plants.

When the surface heat treatment hardening layer is thicker, the rockwell hardness tester can also be used.HRA scale can be used when the thickness of heat treatment hardening layer is between 0.4 and 0.8mm, and HRC scale can be used when the thickness of hardening layer is over 0.8mm.

The three hardness values of vickers, rockwell and surface rockwell can be easily converted into standard, drawing or required by the user.Corresponding conversion tables are given in ISO, ASTM and GB/T.These three conversion tables can be found in the technical data column of shenyang tianxing website.

3. Local heat treatment

For parts with high local hardness requirements, local quenching heat treatment can be carried out by induction heating, etc. Such parts usually need to indicate the location of local quenching heat treatment and local hardness value on the drawing.The hardness test of the part should be carried out in the designated area.The hardness tester can use the rockwell hardness tester to test the HRC hardness value. For example, the surface rockwell hardness tester can be used to test the HRN hardness value if the hardening layer of heat treatment is shallow.

Hardness testing method for tempering heat treatment

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Internal combustion engine valve spring, low, medium and high stress valve spring, safety valve spring, pressure reducing valve, electric regulating valve, pneumatic regulating valve, self-support regulating valve, hydraulic control valve, steam trap, gate valve, as per valve, butterfly valve, ball valve, check valve, special valve, hydraulic valve, electromagnetic valve, etc.Relief valve: spring safety valve by using the spring force, spring loaded relief valve is closed and not closed in two kinds of structure, general inflammable, explosive or toxic medium should choose enclosed, steam or inert gases can choose not enclosed, in spring safety valve with a wrench and without a wrench, wrench mainly is to check the effect of the flexibility of the disc, sometimes also can be used as a manu...
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