Should heat treatment of carburized steel be quenched and tempered or normalized or other treatments

Carburizing steel should be quenched and tempered before heat treatment before carburizing.

Or should it be normalized or something else? Generally considered from several aspects.

1: The processability of the material before carburizing, and the treatment is for processing.

2: The uniformity of the pre-carburizing structure, the treatment is to ensure the uniformity of the post-carburizing organization.

3: The deformation of the workpiece after infiltration, the treatment is to ensure that the deformation is small.

You just need to think about it from these aspects.

It should be normalizing.

The use of carburizing process mainly requires high hardness of the surface, high toughness of the interior, and high strength of the whole.

To meet this requirement, the final heat treatment is mostly made of low-carbon alloy steel, and the process of carburizing and quenching is adopted.

For this kind of hardenable steel, the pre-sequence heat treatment is mostly normalized after forging, (tempering can be added according to requirements).

The requirements are Brinell hardness and grain size.

The aim is to improve the overall performance and improve the machinability.

The object of quenching and tempering is medium carbon (low alloy) structural steel, or low alloy cast steel, which is not suitable for quenching and tempering treatment for low carbon steel, so the heat treatment before carburizing of low carbon steel should be normalizing!

As mentioned earlier, carburized steels are all low-carbon steels and cannot be quenched. Normalizing should be used to obtain an equilibrium structure (p f).

Positive fire state is sufficient.

20crmnti

The carburizing temperature of alloy structural steel is around 900 degrees Celsius. All austenitized. There is no point in conditioning before.

Carburizing and quenching are common heat treatment processes for metal materials.

It can make the surface of the carburized workpiece obtain a high hardness and improve its wear resistance.

Carburizing: It is a kind of metal surface treatment, and most of the carburizing is low-carbon steel.

or low-alloy steel, the specific method is to place the workpiece in an active carburizing medium and heat it to 900-950 degrees Celsius.

of single-phase austenite.

area, after holding for a sufficient period of time, the activated carbon decomposed in the carburizing medium is envied and blind.

It penetrates into the surface of the steel to obtain high carbon on the surface, and the core still retains its original composition.

Similarly, low-temperature nitriding.

Dispose. This is a common heat treatment process for metal materials, which can make the surface of the carburized workpiece obtain high hardness and improve its wear resistance.

There are four basic processes for the overall heat hunger bridge treatment of steel: annealing, normalizing, quenching and tempering. Steel is the most widely used metal in industry, and the microstructure of steel is also the most complex, such as limb head, so there are many kinds of steel heat treatment processes.

If carburizing quenching, when the carburizing layer is thicker, the carburizing temperature can be 930 940, and the parts belong to the thin-walled deformable slag number class and the carburizing layer is required to be shallow, the carburizing temperature can be selected 850 860, and even 830 carburizing can be used.

Hello dear<>

The answer you're looking for: 10 Pre-carburizing heat treatment of steel usually has two main purposes: 1

Removal of internal stress: 10 steel will produce internal stress in the process of cutting, cold deformation and other processing, these old internal stress will affect the shape and dimensional accuracy of the processed parts, and even cause cracks, deformation and other defects. The heat treatment before carburizing can be heated and cooled to release and equalize the internal stress in the 10 steel, so as to improve its processing performance and stability.

2.Improve the microstructure: Heat treatment before carburizing can also improve the microstructure of 10 steel, increasing its hardness and strength.

After heating to a certain temperature, the crystalline body in 10 steel begins to undergo grain boundary diffusion and recrystallization, the original microstructure is homogenized and refined, and it is also conducive to the diffusion and distribution of carbon in 10 steel, so as to lay the foundation for heat treatment after carburizing, and improve its carburizing effect and hardness. In short, heat treatment before carburizing is an indispensable part of the process of 10 steel processing and making noise, which can not only eliminate internal stress, improve processing performance and stability, but also improve the microstructure, increase hardness and strength, lay the foundation for the subsequent carburizing process, and improve its penetration effect and the service life of parts.

Summary. Hello, 10 steel is a commonly used engineering structural steel, heat treatment before carburizing is to heat 10 steel to a certain temperature and keep it warm, so as to change the microstructure and properties of the steel, and prepare for the subsequent carburizing process. Its main purpose is to:

1.Eliminate internal stress in steel: During heat treatment, stress will occur inside the steel, which will affect subsequent processing and use if left untreated.

Through heating and insulation, the stress inside the steel is gradually relieved, thereby improving the stability and durability of the steel. 2.Improving the structure of steel:

In the process of heat treatment before carburizing, the grain of the steel is refined and homogenized due to high temperature heating and heat preservation, so as to improve the microstructure of the steel and improve the strength, hardness and toughness of the steel. 3.Ready for the subsequent carburizing process:

Carburizing is the penetration of carbon elements into the surface of steel to form a high carbonization layer to improve the hardness and wear resistance of steel. Pre-carburizing heat treatment prepares the steel surface for subsequent carburizing processes, making the steel surface easier to carburize and improving the quality and depth of the carburizing layer.

Hello, 10 steel is a commonly used engineering structural steel and guess, heat treatment before carburizing is to heat 10 steel to a certain temperature and keep it warm to change the microstructure and properties of the steel, and prepare for the subsequent carburizing process. Its main purposes are:1

Eliminate internal stress in steel: During heat treatment, stress will occur inside the steel, which will affect subsequent processing and use if left untreated. Through heating and insulation, the stress inside the steel is gradually relieved, thereby improving the stability and durability of the steel.

2.Improve the microstructure of steel: In the process of thermal hail treatment before carburizing, the grain of steel is refined and homogenized due to high temperature heating and heat preservation, so as to improve the microstructure of steel and improve the strength, hardness and toughness of steel.

3.Prepare for the subsequent carburizing process: Carburizing is the penetration of carbon elements into the surface of the steel, forming a high carbonization layer to improve the hardness and wear resistance of the steel.

Pre-carburizing heat treatment prepares the steel surface for the subsequent carburizing process, making the steel surface easier to carburize and improving the quality and depth of the carburizing layer.

Pre-carburizing heat treatment is a very important part of 10 steel processing, but different heat treatment temperatures and times will also have different effects on the properties of steel. For example, a higher heat treatment temperature than Yuanyou can improve the plasticity and toughness of steel, but reduce the hardness; Longer heat treatment times can improve the grain refinement of the steel, but reduce hardness and toughness. I hope mine can help you and I wish you a happy life

Quenching can reflect the effect of carburizing, obtain high hardness, and achieve wear resistance and load resistance. Tempering is to ensure that the quenched product will not be too hard and brittle, and to ensure the service life.

Carburizing is generally done to improve the wear resistance of the surface, and as the carbon concentration increases, the wear resistance is also good. After carburizing, the normalized structure of high-carbon steel obtained without quenching is obtained, and the reticulated carbide pearlite structure is obtained under the condition that the carbon concentration is sufficient and the cooling rate is slow enough, which cannot play a wear-resistant role.

The purpose of quenching is to improve the hardness, the quenching and tempering treatment itself is quenching and high-temperature tempering, quenching is to get as much martensite structure as possible to get high hardness, and tempering is to decompose martensite for the second time to form sophtenite, so as to obtain good mechanical properties.

The strength of Q195 itself is too low, and the carburizing layer is only as deep as 45 after three hours, and the highest is 55HRC after steel quenching and tempering treatment, and the strength cannot go up after quenching, and your carburizing treatment is only three hours.

The hardness of the carburized parts has been greatly improved, but the brittle material is prone to fatigue cracks, and quenching and tempering can increase the toughness of the parts.

Carburizing: In order to increase the carbon content of the surface layer of steel parts and form a certain carbon concentration gradient, the steel parts are heated and insulated in a carburizing medium to make carbon atoms penetrate into the surface layer of the chemical heat treatment process.

Quenching and tempering: A metal heat treatment process to adjust the properties of medium carbon structural steel to make it have the best strength and toughness.

In the mechanism process, in order to improve the surface hardness of the metal material, it can be achieved by carburizing, and quenching and tempering is to change the properties of the metal material by changing the grain of the metal.

The heat treatment of carburized steel is generally quenched and tempered at low temperature after carburizing to obtain a high hardness surface and a strong and tough core. Depending on the composition of the steel, the following heat treatment methods are commonly used.

1) Pre-cooling, direct quenching and low-temperature tempering after carburizing.

This method is suitable for steels with low alloying element content and not easy to overheat, such as 20CrMnTi, 20CrTi, etc.

2) One quenching.

After carburizing, it is slowly cooled to room temperature, reheated and quenched and tempered at low temperature. It is suitable for carbon steel, low-alloy steel workpieces and solid carburized parts that are easy to overheat during carburizing.

3) Two quenching.

After carburizing, it is slowly cooled to room temperature, reheated twice, quenched and tempered at low temperature. It is suitable for intrinsically coarse-grained steel and workpieces with high performance requirements, but the production cycle is long, the cost is high, and it is easy to decarburize, oxidize and deform.

For steel grades such as 18Cr2Ni4Wa with a high degree of alloying, if pre-cooled and quenched after carburizing, there will be a large amount of residual austenite in the seepage layer, which will reduce the hardness. To this end, carburizing air cooling is used in production and then high-temperature tempering is carried out to decompose the residual austenite, and then heated quenching and low-temperature tempering are carried out.

Heat treatment and structure characteristicsThe general process route of carburized parts is: blanking, forging, normalizing, machining, carburizing, quenching + low temperature tempering, grinding. The carburizing temperature is 900 950, and the heat treatment after carburizing usually adopts direct quenching and low temperature tempering, but for steel grades that are easy to overheat during carburizing, such as Mn2, etc., it is necessary to normalize after carburizing to eliminate the superheated structure of coarse grains, and then quenching and low temperature tempering.

The quenching temperature is generally AC1+30 50. The structure in the state of use is: the surface is high-carbon tempered martensitic plus granular carbide plus a small amount of residual austenite (hardness up to HRC58 62), and the core is low-carbon tempered martensitic plus ferrite (quenched) or ferrite plus Torrosite (unquenched).

Carburizing is the process by which carbon atoms penetrate into the surface layer of steel. It is also to make the workpiece of low carbon steel have the surface layer of high carbon steel, and then after quenching and low temperature tempering, the surface layer of the workpiece has high hardness and wear resistance, and the central part of the workpiece still maintains the toughness and plasticity of low carbon steel. Generally, the temperature of carburizing is 900 950, the quenching temperature is 800 850, the oil quenching temperature is 180 200.

Whether it can be quenched directly after heat treatment carburizing mainly depends on the following points:

1. Look at the material:

If it is a steel containing alloying elements such as titanium, vanadium, molybdenum, tungsten and other alloying elements that can refine the grain, such as 20crmnti, 20crmnmo, 18cr2ni4wa and so on, it can be pre-cooled to 810 830 by carburizing temperature and quenched directly, if it is not these steels, but 20cr, 20mn simn these steels are not.

2. Look at the technical requirements:

The technical requirements are not high, and direct quenching after carburizing can be used. Otherwise, you can't.

3. Look at the user requirements:

The user requires that you can be directly quenched after carburizing, and you can not be quenched directly after the user requires carburizing, so you can't be quenched directly, otherwise, people will not give money.

If it is carburizing at high temperature, it can be quenched directly and tempered at low temperature.