What are the heating methods of quenched workpieces?

If it is a single piece, it will be a high-frequency machine! If the amount is large, use a quenching furnace! I'm a high-frequency machine, and you can take a look at it again.

Summary. Under normal heating and quenching conditions, problems such as microstructure deformation, tissue destruction, and microstructure changes may occur during the quenching process. Workaround:

1.First of all, the quenching temperature and time should be determined according to the characteristics of the quenching material to ensure the quenching quality. 2.

Secondly, a reasonable quenching process should be adopted, such as temperature rise and fall rate, quenching time, etc., to ensure the quenching quality. 3.In addition, a reasonable quenching environment, such as quenching temperature, quenching time, quenching environment, etc., should be used to ensure the quenching quality.

4.Finally, reasonable quenching devices should be used, such as quenching furnaces, quenching boxes, etc., to ensure the quality of quenching. In short, in order to obtain good quenching quality under normal heating and quenching conditions, it is necessary to adopt reasonable quenching temperature, quenching time, quenching environment and quenching device to ensure quenching quality.

Under normal heating and quenching conditions, problems such as tissue widening, tissue destruction, and tissue structure changes may occur during the quenching process. Workaround:1

First of all, the quenching temperature and time should be determined according to the characteristics of the quenching material to ensure the quenching quality. Caution withered 2Secondly, a reasonable quenching process should be adopted, such as temperature rise and fall rate, quenching time, etc., to ensure the quenching quality.

3.In addition, a reasonable quenching environment, such as quenching temperature, quenching time, quenching environment, etc., should be used to ensure the quenching quality. 4.

Finally, reasonable quenching devices should be used, such as quenching furnaces, quenching boxes, etc., to ensure the quality of quenching. In short, in order to obtain good quenching quality under normal heating and quenching conditions, it is necessary to adopt reasonable quenching temperature, quenching time, quenching environment and quenching device to ensure quenching quality.

Can you elaborate on that a little bit more?

Under normal heating and quenching conditions, the quenching treatment of steel is a commonly used heat treatment method, which can improve the mechanical properties of steel and improve the tensile strength, compressive strength and wear resistance of steel. There are four main steps of quenching treatment: first, the steel is heated to the quenching temperature, which is generally 850-950; Secondly, the steel is kept at the quenching temperature of the slow cover for a certain time, generally 30-60 minutes; Then, the steel is cooled from the quenching temperature to room temperature, and the cooling rate is generally 50-100 per hour; Finally, the steel tuber was quenched and then subjected to a hardness test to determine the quality of the quenching treatment.

In addition, quenching treatment can also improve the microstructure of the steel, make the microstructure of the steel more compact, improve the corrosion resistance and heat resistance of the steel, and thus improve the service life of the steel.

Heat treatment quenching cooling methods include water cooling, oil cooling, air cooling, water quenching oil cooling, nitrate plus air cooling, alkali bath plus air cooling, mercury liquid shed cooling, lead bath, etc.

Quenching and cooling is an industrial smelting and forging process. It is widely used in smelting, machine tool forging, fine processing and other industrial production.

It is necessary not only to cool quickly to ensure that the quenched workpiece obtains the martensitic structure, but also to reduce deformation and prevent cracks. Therefore, cooling is a key operation related to the quality of quenching.

Heat treatment quenching cooling methods include water cooling, oil cooling, air cooling, water quenching oil cooling, nitrate plus air cooling, alkali bath plus air cooling, mercury liquid cooling, lead bath, etc.

Quenching and cooling is an industrial smelting and forging process. It is widely used in smelting, machine tool forging, fine processing and other industrial production.

During quenching and cooling, it is necessary to cool quickly to ensure that the quenched workpiece obtains martensitic structure, and to reduce deformation and prevent cracks. Therefore, cooling is the key to the quality of quenching.

Quench. It is to heat the steel above the critical temperature, keep it warm for a certain time, and then cool it at a temperature greater than the critical cooling rate, so as to obtain an unbalanced structure dominated by martensite (there are also bainite or single-phase austenite as needed.

A heat treatment process.

Method. The purpose of quenching is to make the supercooled austenite carry out martensite or bainite transformation to obtain martensite or bainite structure, and then cooperate with tempering at different temperatures to greatly improve the rigidity, hardness, wear resistance and fatigue strength of steel.

and toughness, etc., so as to meet the different use requirements of various mechanical parts and tools.

The quenching and holding time is determined by various factors such as the heating method of the equipment, the size of the parts, the composition of the steel, the amount of furnace and the power of the equipment. For integral quenching, the purpose of insulation is to make the internal temperature of the workpiece slip uniform and consistent. For all types of quenching, the holding time ultimately depends on obtaining a good quenching heating structure in the area where quenching is required.

Heating and heat preservation are important links affecting the quality of quenching, and the microstructure obtained by austenitization directly affects the performance after quenching. Generally, the austenite grain of steel parts is controlled at 5 8 grades.

The hardness of the quenched workpiece affects the quenching effect. Quenched workpieces are generally determined by a Rockwell hardness tester to determine their HRC value. The HRA value can be determined for quenched thin hard steel plates and case-hardened workpieces, while the HRC value can be determined using a surface Rockwell hardness tester for quenched steel plates with a thickness of less than 5 mm, shallow surface-hardened workpieces and hardened steel rods with a diameter of less than 5 mm.

In welding carbon pants forest steel and certain alloy steels.

, quenching may occur in the heat-affected zone and harden, and cold cracks are easy to form, which should be prevented during the welding process.

Due to the hardness and brittleness of the metal after quenching, the surface residual stress is generated.

It will cause cold cracks, and tempering can be used as one of the means to eliminate cold cracks without affecting the hardness.

Quenching is more suitable for parts with small thickness and diameter, and for oversized Hu doumu parts, the quenching depth is not enough, and the same problem exists in carburizing, so it should be considered to add chromium and other alloys to the steel to increase strength.

Quenching is one of the basic means of strengthening steel materials. Martensite is the hardest phase in the structure of iron-based solid solution, so high hardness and high strength can be obtained by quenching steel. However, the brittleness of martensitic is very large, and there is a large quenching internal stress inside the steel after quenching, so it is not suitable for direct application and must be tempered.

1.Annealing of steel.

Annealing is a commonly used preparatory heat treatment process in production. After annealing, the blanks of most machine parts and tools and molds can eliminate the internal stress and structural inhomogeneity of casting, forging and welding parts; It can improve and adjust the mechanical properties of steel, and prepare for the next process of elimination. Annealing can be used as the final heat treatment for parts that do not have high requirements for performance and are not very important, as well as some ordinary castings and weldments.

The annealing of steel is a heat treatment process in which the steel is heated to the appropriate temperature, kept warm for a certain period of time, and then slowly cooled to obtain a near-equilibrium structure. The purpose of annealing is to homogenize the chemical composition, improve mechanical and process properties, eliminate or reduce internal stresses, and prepare the part for final heat treatment.

There are many types of annealing processes for steel, which can be divided into two categories according to the heating temperature: one is annealing above the critical temperature (AC3 or AC1), also known as phase change recrystallization annealing. Including complete annealing, incomplete annealing, isothermal annealing, spheroidization annealing and diffusion annealing, etc.; The other type is annealing below the critical temperature (AC1), also known as low-temperature annealing.

These include recrystallization annealing, stress relief and dehydrogenated annealing. According to the cooling method, it can be divided into continuous cooling annealing and isothermal annealing.

2.Quenching and tempering of steel.

The quenching and tempering of steel hobbles is a very important and widely used process in the heat treatment process. Quenching can significantly improve the strength and hardness of steel. If it is tempered with different temperatures, the internal stress of quenching can be eliminated (or reduced), and the combination of strength, hardness and toughness can be obtained to meet different requirements.

Therefore, quenching and tempering are two inseparable heat treatment processes.

Quenching of steel. Quenching is a heat treatment process in which steel is heated above the critical point, and then cooled at a temperature greater than the critical cooling rate (VC) after heat preservation to obtain a martensitic or lower bainite structure.

Tempering of steel. Tempering is a heat treatment process in which quenched steel is heated to a certain temperature below the A1 point for a certain period of time, and then cooled to room temperature in an appropriate way. It is the next heat treatment process immediately after quenching, which determines the structure and properties of the steel in the use state, and is related to the service life of the workpiece, so it is a key process.

The main purpose of tempering is to reduce or eliminate quenching stress; Ensure the corresponding organizational transformation, so that the size and performance of the workpiece are stable; Improve the thermal and plastic properties of steel, choose different tempering temperatures, and obtain the appropriate combination of hardness, strength, plasticity or toughness to meet the performance requirements of different workpieces.

The purpose of quenching is to improve the hardness and strength of quenched parts.

Based on the critical point of phase transformation of steel, fine and uniform austenite grains should be formed when heated, and fine martensite structures should be obtained after quenching. The quenching heating temperature range of carbon steel. The quenching temperature selection principle illustrated in this diagram also applies to most alloy steels, especially low-alloy steels.

The heating temperature of sub-eutectic steel is 30 50 above the AC3 temperature. From the figure, the state of the steel at high temperature is in the single-phase austenite (a) region, so it is called complete quenching. If the heating temperature of the sub-eutectic steel is higher than AC1 and lower than the AC3 temperature, the partial pre-eutectic ferrite is not completely converted into austenite at high temperature, which is incomplete (or subcritical) quenching.

The quenching temperature of the eutectic steel is 30 50 above the AC1 temperature, and the temperature range is in the austenite and cementite (A+C) duplex zone. Therefore, the normal quenching of eutectic steel is still incomplete quenching, and the structure of cementite distributed on the martensitic matrix is obtained after quenching. This - the state of the tissue has high hardness and high wear resistance.

For eutectic steel, if the heating temperature is too high, the first eutectic cementite will be dissolved too much, or even completely, the austenite grains will grow and the austenite carbon content will also increase. After quenching, the coarse martensitic structure increases the stress and microcracks in the quenching microzone of the steel parts, and increases the deformation and cracking tendency of the parts. Due to the high austenite carbon concentration, the martensitic point decreases and the residual austenite mass increases, which reduces the hardness and wear resistance of the workpiece.

In actual production, the selection of heating temperature should be adjusted according to the specific situation. For example, the carbon content in sub-eutectic steel is the lower limit, and the upper temperature limit can be used when the furnace loading volume is large and the depth of the hardening layer of the part is increased. If the shape of the workpiece is complex, the deformation requirements are strict, etc., the lower temperature limit should be adopted.

Buy this heat treatment brochure to find relevant data according to your material, and then choose the appropriate temperature according to the size and shape of your workpiece, furnace loading and other conditions.

The quenching heating temperature of various steels is mainly determined by the type and critical point of its structure.

Answer: How to choose the quenching heating temperature.

It is a heat treatment process in which the steel is heated to a temperature above the critical temperature AC3 (sub-eutectic steel) or AC1 (super-eutectic steel), kept warm for a period of time to make it fully or partially austenitized, and then cooled to below ms (or isothermal near ms) at a cooling rate greater than the critical cooling rate for martensite (or bainite) transformation.