Introduction to Laser Quenching Equipment

1、 Laser quenching

Laser quenching is a quenching technology that uses laser to heat the surface of a material above the phase transition point. As the material cools down, austenite transforms into martensite, thereby hardening the surface of the material. Adopting laser quenchingoutsideNoodles have a high heating and cooling rate, a short process cycle, and do not require external quenching media.It has unique advantages such as small workpiece deformation, clean working environment, no need for precision machining such as gear grinding after processing, and the processed size is not limited by the size of the heat treatment equipment.

IIQuality advantage

Power density of laser quenchingHigh degree,Cooling rateQuick, no need for cooling media such as water or oil,It is a clean and fast quenching process. Compared with induction hardening, flame hardening, and carburizing hardening processes, laser hardening has a uniform hardening layer and higher hardness (generally higher than induction hardening)1-3HRC）The workpiece deformation is small, the heating layer depth and heating trajectory are easy to control, and automation is easy to achieve. It does not require designing corresponding induction coils according to different part sizes like induction hardening, and the processing of large parts does not need to be limited by the furnace size during chemical heat treatment such as carburizing and quenching. Therefore, it is gradually replacing traditional processes such as induction hardening and chemical heat treatment in many industrial fields. It is particularly important that the deformation of the workpiece before and after laser quenching can be almost ignored, making it particularly suitable for surface treatment of high-precision parts.

IIITechnical Characteristics

The depth of laser hardening layer varies depending on the composition, size and shape of the part, as well as the laser process parameters. Generally, it is0.3~2.0mmBetween ranges. Quenching the tooth surface of large gears and the shaft neck of large shaft parts can maintain the basic surface roughness and meet the actual working conditions without the need for subsequent mechanical processing.

Laser melting quenching technology utilizeslaser beamHeat the surface of the substrate above the melting temperature,The process of rapid cooling and solidification crystallization of the melted layer surface due to thermal conductivity cooling inside the substrate. The obtained melt quenched microstructure is very dense, and the microstructure along the depth direction is sequentially melted-Solidification layer, phase transformation hardening layer, heat affected zone, and substrate. The hardening depth, hardness, and wear resistance of the laser melted layer are deeper and higher than those of the laser quenched layer. The drawback of this technology is that the roughness of the workpiece surface is damaged to a certain extent, which generally requires subsequent mechanical processing to restore. In order to reduceAfter laser melting treatment, the surface roughness of the parts is reduced, and the subsequent processing volume is reduced. Huazhong University of Science and Technology has formulated a special laser melting quenching coating, which can significantly reduce the surface roughness of the melting layer. The surface roughness of various materials such as rollers and guides in the metallurgical industry that undergo laser melting and solidification treatment is close to the level of laser quenching.

4Applicable materials

Laser quenching has been successfully applied to the surface strengthening of vulnerable parts in the metallurgical, mechanical, and petrochemical industries, especiallyImprovingroller, leadIn terms of the service life of vulnerable parts such as gears, scissors, etc., significant effects have been achieved, resulting in significant economic and social benefits. In recent years, surface strengthening of components such as molds and gears has also been increasingly widely applied.

5practical application

Laser quenching technology can strengthen the surface of various guide rails, large gears, shaft necks, cylinder walls, molds, shock absorbers, friction wheels, rollers, and roller parts. The applicable materials are medium and high carbon steel, cast iron.

Application example of laser quenching: laser quenching strengthened cast iron engine cylinder movementcoatingIts hardness has increasedHB230Raise toHB680Improved service life2~3Twice.

Gears are widely used components in the mechanical manufacturing industry.In order to improve the load-bearing capacity of gears, surface hardening treatment is required.However, traditional gear hardening processes, such as surface chemical treatments such as carburizing and nitriding, as well as induction surface quenching and flame surface quenching, have two main problems: large deformation after heat treatment and difficulty in obtaining a uniformly distributed hardening layer along the tooth profile, which affects the service life of the gear.

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VICharacteristics of laser quenching

1The quenched parts do not deform, and the thermal cycling process of laser quenching is fast.

2Almost no damage to surface roughness is achieved through the use of an anti oxidation protective thin coating.

3Laser quenching without cracking, precise quantitative CNC quenching.

4CNC quenching with precise positioning for local, groove, and trough quenching.

5Laser quenching is clean, efficient, and does not require cooling media such as water or oil.

6The hardness of quenching is higher than that of conventional methods, the microstructure of the quenched layer is fine, and the strength and toughness are good.

7. Laser quenching is a fast heating and self-excited cooling process that does not require furnace insulation or coolant quenching. It is a pollution-free, green and environmentally friendly heat treatment process that can easily achieve uniform quenching of large mold surfaces.

8. Due to the fast heating speed and small heat affected zone of laser, as well as the surface scanning heating quenching, i.e. instantaneous local heating quenching, the deformation of the processed mold is very small.

9. Due to the small scattering angle of the laser beam and its good directionality, it can accurately perform local quenching on the surface of the mold through a light guiding system.

10. The depth of the hardened layer of laser surface quenching is generally0.3～2mm.

Partial parameters