Laser quenching technology uses a focused laser beam to be incident on the surface of the steel material, causing the temperature to quickly rise above the phase change point. When the laser is removed, due to the rapid thermal conductivity of the inner layer material that is still at a low temperature, the heated surface layer Rapidly cools to below the martensitic transformation point to complete the surface transformation hardening of the workpiece. The principle of laser quenching is the same as that of induction quenching and flame quenching. However, its technical characteristics are that it uses higher energy density, faster heating speed, no need for quenching medium, small deformation of the workpiece, easy control of the heating layer depth and heating track, and easy automation, so it can be gradually replaced in many industrial fields. Traditional processes such as induction hardening and chemical heat treatment. Laser quenching can cause significant changes in the structural structure and properties within the range of 0.1 to 2.0mm on the surface of the workpiece. Laser melting and quenching use laser to melt the metal surface. After the laser beam is removed, the molten metal is directly quenched from liquid to solid to form a surface-hardened layer. Since laser melting and quenching allow the metal surface to melt, a higher power density and slower scanning speed can be used during actual operation than laser quenching, so the depth of the laser melting and quenching layer is deeper than the former.

When the laser output power is 3.5kw, the depth of the hardened layer of laser melting and quenching on the surface of large rolls can reach more than 2 mm. The disadvantage of laser melting and quenching is that the surface roughness after laser processing decreases, and the degree of decrease depends on the process parameters of laser processing, while laser surface quenching can basically keep the surface roughness of the workpiece unchanged. The common feature of laser quenching and melting treatment is that there is no need to change the composition of the material. It mainly uses the characteristics of the roll material itself to produce martensite transformation to strengthen the roll surface. Before laser quenching and fusion quenching, a layer of light-absorbing paint needs to be pre-coated to enhance the laser absorption rate of the roll surface. For laser melting treatment, the coating used should also have the effect of leveling and slagging the laser molten pool. Therefore, the formulation of the coating is crucial to the smooth execution of the laser process and its impact on the structure and performance of the hard surface layer. Laser quenching is mainly used to treat iron-based materials. Its basic mechanism is to scan the surface of the workpiece with a high-energy laser beam. The surface material of the workpiece absorbs the laser radiation energy and converts it into heat energy. Then, through heat conduction, the temperature of the surrounding material increases at an extremely fast rate. Above the austenite phase transformation and below the melting point, through the self-cooling effect of the material matrix, the heated surface material is rapidly cooled at a rate exceeding the critical cooling rate of martensite phase transformation, and then phase transformation hardening is completed. Because of the large degree of superheating and undercooling during the laser quenching process, the grains of the hardened layer are extremely fine, the dislocation density is extremely high, and stress is formed on the surface, which can greatly improve the wear resistance, fatigue resistance, corrosion resistance, and corrosion resistance of the workpiece. Anti-oxidation and other functions extend the service life of the workpiece.

Laser quenching, also known as laser heat treatment and laser hardening, is a high-tech technology that uses a concentrated laser beam to quickly heat the surface of metal materials to cause phase transformation to form a martensite-hardened layer. It is divided into laser phase change hardening, There are three process methods: laser condensation hardening and laser shock hardening. Skill features:

1. Laser-quenched martensite has finer grains, higher dislocation density, higher hardness, and better wear resistance.

2. With minimal or even no deformation, it is suitable for processing high-precision parts. In some cases, it can be used as the final processing step of materials and parts.

3. No tempering is required, the quenched surface obtains compressive stress and is not prone to cracks.

4. If it has good workmanship and flexibility, it has a wide range of applications and can easily handle large-sized workpieces and local areas such as trenches, grooves, deep holes, inner holes, and blind holes.

5. The depth of the hardened layer can be adjusted as needed.

6. The hardness gradient is very small, and the hardness does not change at all with the depth of the laser-hardened layer.

7. A wide range of suitable materials, including various medium and high carbon steels, tool steels, mold steels, and cast iron materials.

8. The processing process is automatically controlled, the construction period is short, and the quality is stable.

9. Low carbon and environmentally friendly, no cooling medium is required, and no exhaust gas or wastewater is discharged.