The heat treatment of steel is to change the internal structure of the steel through heating, heat preservation and cooling in a solid state, thereby changing the mechanical properties of the steel. Common heat treatment methods include quenching, tempering, normalizing, annealing, and tempering.
Annealing Steel Definition:
The steel is heated to a certain temperature and kept at this temperature, and then slowly cooled to room temperature. This heat treatment process is called annealing. Commonly used annealing methods include complete annealing, spheroidizing annealing and stress relief annealing.
Normalizing Steel Definition:
The metal heat treatment process of heating steel to a certain temperature, keeping it for a period of time, and then cooling in the air is called normalizing. The purpose of normalizing and annealing is basically the same, but the cooling rate of normalizing is faster than that of annealing, resulting in a finer structure, higher hardness and strength than annealing.
The normalizing process of steel is used in different type steel material with applications from low carbon steel, medium carbon steel, tool steel, bearing steel, carburized steel, steel castings, large forgings steel, to improve hardness, strength, and wear resistance.
Quenching Steel Definition:
The heat treatment method in which steel is heated to a certain temperature and quickly cooled in water (or oil) after heat preservation is called quenching. Its purpose is to improve the strength, hardness, and wear resistance of the material. Commonly used quenching methods are: single-medium quenching, dual-medium quenching, and graded quenching. Role of Quenching media in martensitic transformation gives an insight on critical cooling rate. Quenching media has water, oil or aqueous solution of salt and alkali.
Tempering Steel After Hardening Definition:
Tempering Steel After Hardening process is reheat the quenched steel to a certain temperature, keep it for a period of time, and then cool it to room temperature in a certain way. This heat treatment method is called tempering. Tempering is the continuation of quenching. The quenched steel must be tempered.
The purpose of tempering is to reduce or eliminate the internal stress generated during quenching process, appropriately adjust the strength and hardness of the steel, stabilize the structure, and bring balance between hardness and toughness.
The types of tempering include low-temperature tempering, medium tempering and high-temperature tempering. Among them, "quenching ten high-temperature tempering" is also called "quenching and tempering treatment".
Chemical Heat Treatment Steel Definition:
The chemical heat treatment of steel is a heat treatment process in which the workpiece is placed in a chemical medium for heating and heat preservation to change the chemical composition of the surface, thereby changing the surface properties. Common methods include carburizing, nitriding, and liquid carbonitriding.
Surface Hardening Steel Definition:
Surface Hardening Steel process is through rapid heating makes the surface of the workpiece reach the quenching temperature and cooling immediately before the heat is transferred to the core. Compared with the surface hardening heated by flame, ROCHO INDUCTION provide surface induction hardening technology, the induction hardening heat is generated in the workpiece itself, so the energy consumption is small and the thermal efficiency is high. The hardened metal undergoes martensite transformation, which increases the hardness and wear resistance of the workpiece.
ROCHO INDUCTION specializes in providing various induction hardening solutions, whether integral hardening or scanning hardening. Our experienced engineers can provide customized evaluation and system solutions for your workpieces and requirements. Contact ROCHO INDUCTION now for more information about our induction hardening equipment.
