Quenching and tempering treatment usually refers to the quenching and subsequent high-temperature tempering of steel and is a common process in the heat treatment of steel. Its purpose is to improve the mechanical properties of the metal through appropriate heat treatment processes so that it has good comprehensive mechanical properties. The following is a detailed introduction to the combination of quenching and high temperature tempering：

1.Quenching
01Purpose
Improve hardness and strength: The austenite of steel is transformed into martensite through quenching, which significantly improves the hardness and strength of the material.
Formation of martensite structure: The martensite structure has high hardness and strength, but is relatively brittle.

02 process
Heating: Heating the steel to the austenitizing temperature (usually between 750°C and 950°C) so that its internal structure completely transforms into austenite.
Rapid Cooling: Rapidly cooling steel (usually in water, oil, or air) to transform austenite into martensite.

03 results
Improved hardness: The hardness of quenched steel is greatly improved and it can withstand greater mechanical stress.
Increased brittleness: Due to the presence of martensitic structure, quenched steel has poor toughness and is prone to brittle fracture.

2.High temperature tempering
01Purpose
Improve toughness and plasticity: Through high-temperature tempering, the brittleness after quenching can be reduced and the toughness and plasticity of the material can be improved.
Eliminate internal stress: The internal stress generated during the quenching process will cause the material to become brittle. High-temperature tempering can effectively eliminate these internal stresses.
Adjusting Hardness: Adjusting the hardness of steel through tempering to achieve the expected performance requirements.

02 process
Heating: Heat the quenched steel to between 500°C and 650°C and keep it warm for a period of time.
Cooling: Cooling is usually slow to ensure structural stability.

03 results
Hardness reduction: High-temperature tempering will moderately reduce the hardness of the material, but still maintain it at a high level.
Increased toughness: The toughness of tempered steel is significantly improved and can resist impact and fatigue damage.
Internal stress relief: The elimination of internal stress reduces the risk of material cracking and improves dimensional stability.

3.The comprehensive effect of conditioning treatment

01Advantages
Good comprehensive mechanical properties: The quenched and tempered steel has high hardness, high strength, good toughness and plasticity, and is suitable for a variety of application needs.
Dimensional stability: By eliminating internal stress, the dimensional stability of the material during use is ensured.
Widely used: Suitable for manufacturing various mechanical parts, such as shafts, gears, springs, etc., widely used in machinery manufacturing, automobile industry, aerospace and other fields.

02Typical applications
Mechanical parts: such as gears, bearings, connecting rods, etc., parts that require high strength and high toughness.
Structural parts: such as steel in bridges and building structures, which require durable and stable performance.
Tools: Such as cutting tools, molds, etc., tools that require high hardness and wear resistance.

03Summary
The combination of quenching and high-temperature tempering optimizes the hardness, strength and toughness of the steel through the quenching and tempering process, giving it excellent comprehensive mechanical properties. This treatment method is very important in industrial applications, ensuring the reliability and durability of the material in actual use.