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2018 - 04 - 18

Springs are ubiquitous in all kinds of machines—from consumer products to heavy industrial equipment, take apart anything that involves a mechanism, and chances are, you’ll find a spring inside. Springs are storage devices for mechanical energy—think of them as analogous to batteries! The earliest spring-driven clocks appeared in the 1400s. Fast-forward some 600 years, you still have to charge the Apple Watch everyday, and it’s not nearly as fast as winding a clock…but I digress.My personal fascination with springs began with Slinkies and wind-up toys, and countless mechanical pencils were sac...

Inspection content and specification for spring parts(part 3)

2018 - 07 - 28

6.1.10 detection of parallelism between ends of springs: the spring is placed vertically on the plate.The difference between the maximum and minimum values of the surface of the end ring is measured by the dial indicator. The difference between the maximum and minimum values is the parallelism deviation between the ends of the spring.6.1.11 spring straightness detection: put the spring level on the plate and roll one.Zhou, determine its maximum bending position and measure the gap between the maximum bending point and the flat plate with a feeler gauge.The measured gap is the deviation of the ...

Common specifications of spring

2018 - 08 - 09

The number of diameter length is described!(1) the diameter of the spring wire d: is the wire diameter of the spring. (2) the maximum outer diameter of the spring outer diameter D: spring. (3) the inner diameter of the spring D1: the smallest outer diameter of the spring.(4) the middle diameter of the spring D2: the average diameter of the spring. Their formula is: D2 = (D + D) = 2 = D 1 + D = D D.(5) apart from the support ring, the distance between the two adjacent circles of the spring corresponding to the axial distance of the point on the middle diameter is t:, and is expressed ...

What is the salt spray test?

2018 - 08 - 23

Salt fog refers to the dispersion system composed of salt micro droplets in the atmosphere. It is one of the three defense series of artificial environment. Many enterprise products need to simulate the destructive nature of the marine surrounding climate to the products. The salt fog test is a simulation of this phenomenon, so the test equipment, salt fog test box, came into being.Salt fog can be divided into two categories, one is natural environmental exposure test, the other is artificial accelerated salt spray environmental test. The artificial simulated salt fog environment test is a kin...

Analysis of deformation prevention measures for heat treatment of metal spring(part 1)

2018 - 09 - 07

There are two types of heat treatment deformation: one is the size change, the other two is the change of part geometry. Different methods of heat treatment, deformation and deformation prevention of parts size and geometry are also different.The longer the holding time and the higher the temperature are, the more carbon is dissolved into austenite and the larger the expansion of martensite is. The expansion of martensite is the largest, followed by upper bainite, and the volume change of lower bainite and troostite is very small. At low temperature tempering, martensite shrinks and the amount...

Spring machine regular maintenance and daily maintenance is very important

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...

Analysis of spring corrosion

2018 - 09 - 29

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...

Selection of spring material

2018 - 10 - 16

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 ...

Proper use of the spring

2018 - 10 - 26

Please avoid the improper way of using (1) more than the use of the maximum compression (300000 back to the conditions, after a close with the use of a long) stress causing the wreck, close to close with the use of a long, can make the spring line department gradually close to that, because of the high spring constant change caused by load curve with high, nearly and produce high stress to make spring break, please do not use more than 300000 times.The use of the spring without prepressure due to the gap caused the spring up and down vibration caused the spring distortion, if there is prepress...

NEW INFORMATION / More

Types of Springs and their Applications

2018 - 04 - 18

Types of Springs and their Applications

2018 - 08 - 06

Inspection content and specification for spring parts(part 5)

2018 - 08 - 17

Detection of the characteristics of 7.2 torsion springsWhen measuring torque, the size of the torsional spring axis must be suitable. The inner diameter of the spring should be kept to a certain gap, and the friction force and friction torque caused by the contraction of the inner diameter of the spring should be avoided, and the measurement accuracy should be affected. But the spindle can not be too small, otherwise it will cause the offset between the external torque and the measuring torque center, resulting in the error of the torque measurement. The specific testing program for torsion sp...

Steps of hardware spring pressure test

2018 - 09 - 03

The spring pressure test of metal springs usually uses electronic digital spring tension and compression testing machine. Electronic digital spring tension and compression testing machine is a special instrument for testing the deformation and load relationship characteristics of tension and compression springs. It is suitable for testing the working load of the tension and compression spring under a certain working length, and also for testing the elastic load of elastic devices such as rubber and spring.The pressure test of metal springs is generally divided into the following steps:1. Compr...

Study on factors influencing decarburization of 55SiCr surface of spring steel during heating

2018 - 09 - 14

55SiCr is the high-grade steel used for automobile suspension springs. The suspension springs bear the reciprocating compression motion in the process of automobile driving, and play the role of buffer and shock absorption, which has high requirements on the performance of steel.Decarburization is one of the main problems in the hot processing of spring steel. Decarburization of spring steel surface will seriously damage the fatigue performance of spring, especially when the total decarburization of ferrite occurs on spring steel surface, the fatigue limit of spring can be reduced by 50%.At pr...

Spring material selection method

2018 - 09 - 26

Type of paint used on spring surfaces

2018 - 10 - 11

Type of paint used on spring surfacesThe oxidation treatment of the spring (also known as bluish, blackened, cooked black, etc.) is mainly used to prevent the corrosion of the spring, and also to make the spring appearance bright.Oxidation treatment methods include: alkaline oxidation, alkali free oxidation and electrolytic oxidation.Spring oxidation treatment is often alkaline oxidation treatment, in the presence of oxidants (such as sodium nitrite) in caustic sodium solution.As the solution approaches the boiling point, the iron on the surface of the spring dissolves and forms sodium ferrite...

Surface treatment of springs

2018 - 10 - 22

The working characteristic of tension spring

2018 - 12 - 03

Today, the development of science and technology, spring has been a very important hardware accessories in our life, different products use the spring is not the same, the longest used spring can be roughly divided into: tension spring, torsion spring, compression spring, spiral spring, flat spring.The following is a very practical tension spring characteristics of the application:Many different products or hooks are used to ensure that the tension spring tension source, tension spring and compression spring work in the opposite way, tension spring is in the extension or pull out of the revers...

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Hardness testing method for tempering heat treatment

日期： 2018-09-17

浏览次数: 80

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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