Induction assisted laser-cladding a new and effective method for producing high wear resistant coatings on steel components

摘要

Despite better wear resistance two problems hinder the wide industrial application of lasercladding: 1) low cladding speeds and deposition rates; and 2) crack formation (within the clad when using heat treatable steels as base material and within brittle hard-facing alloys). To avoid these disadvantages, an additional power source, which is suitable for the laser-cladding process, is needed. The purpose of this additional power source is to reduce the temperature gradient within the clad and base material while cooling and to deliver supplementary inexpensive energy. Induction heating is a smart, easily adjusted and adaptable technique to address this need. The combination of induction preheating followed by laser-cladding, for example, makes it possible to coat high carbon steels (AISI 1043) such as cold work tool steels (AISI O2) with hard, wear resistant alloys (Nicrobor 40, Deloro 60). Although cracks within the clad can be avoided in every case, induction assisted laser-cladding allows the simultaneous generation of martensitic layers within the base material. This opens the possibility for laser-cladding and induction heat treatment in one step. Furthermore the cladding speed and the deposition rate can be increased by ten times over conventional laserbeam-cladding. As a result, production cost can be reduced despite higher technological expenditure. Nevertheless, the typical advantage of laser-cladding (namely, low dilution of base material into the clad material) is maintained.