Process and background information
During laser hardening, the carbon-containing edge region of a component is heated to temperatures between 900 and 1,500°C by a high-intensity laser beam. This local introduction of heat causes the steel to become austenitised. While the laser beam moves, the surrounding material quickly cools the heated zone, causing the formation of martensite. This rapid self-quenching eliminates the need for additional quenching media. The process makes it possible to harden only specific functional surfaces in a targeted manner, while maintaining the ductility of the remaining component.
Laser hardening is an edge layer hardening process that leaves the chemical composition unchanged. Laser hardening is also a particularly good choice for large workpieces that need to be hardened only in certain areas.
By means of point-by-point or two-dimensional heating, laser beams can be used to heat the steel surface to its austenitising temperature. Heating with laser beams is very fast. This facilitates quenching, which takes place almost by itself, on account of the fast heat conduction.
Caption: Process: Laser hardening
Combination with other processes
Laser hardening may serve as an alternative heat treatment process to inductive hardening or flame hardening. It is also ideal as a subsequent surface treatment for protecting component areas that are prone to sustaining wear and tear. The process can be effortlessly integrated into existing production processes, e.g. in conjunction with processing or production machines.
The advantages at a glance
- Precise hardening: Local hardening of specific partial areas.
- Minimum warping: Low heat input reduces material deformation.
- High reproducibility: Exact control of the heat input.
- No quenching medium: Self-quenching makes additional processes unnecessary.
Applications and suitable materials
Laser hardening is used in various industries, including toolmaking, the automotive industry and agricultural technology. It is particularly suitable for components with complex geometries or heavily stressed components, such as camshafts, cutting tools or gear wheels.
Typical materials are:
- Tool steels (e.g. cold and hot worked steels)
- Quenched and tempered steels
- Sectional steels
- Stainless steels resistant to corrosion (containing 0.2% carbon or more)
- Cast iron