Study On The Technology Of Laser Irradiation For Decreasing The Core Loss Of Grain Oriented Silicon Steel

With the rapid development of power industry, the demand for grain oriented silicon steel is increasing gradually, and the requirement for performance is increasing as well, so more concern has been put on decreasing the core loss of the grain oriented silicon steel. In order to improve the performance, this paper has focused on the technology of laser irradiation for decreasing the core loss of grain oriented silicon steel. With the core mechaniam of domain refinement for decreasing the core loss by laser irradiating in mind, the main work and progress in this paper is as follow:(1) By adding surfactant and using the new technology, this paper has successfully compounded the new ferrofluids with high stability for the observation of the domain structure. According to the results of the examination, the diameter of the magnetic particle in this paper is within nanometer scale, about50nm, and the ferrofluids may display the domain structure clearly being used easily, and the storage life of this type ferrofluids can be extended for3months.(2) Analysis the mechanism of decreasing the core loss by laser irradiation. According to the results derived, this paper points out the main influence factors in the technology of laser irradiation, including the ratio of180°domain wall that can pass through the area of laser irradiation(a), the number of the lines of the laser irradiation in a single grain(n), the thickness of the grain oriented silicon steel, etc. Simultaneously, this paper get the main parameters in this technology. With the calculated result of the optimum grain size(5.85mm) and concerning the parameter of a,5mm is selected for the interval of the lines of laser irradiation.(3) By the experiment of laser irradiation, this paper has studied the influencing characteristics of three aspects of the steel on the effect of domain refinement for decreasing the core loss. The demonstrated results are as follow:on the condition of the samples with close orientation, the higher initial core loss, the higher reduction; the higher orientation, the lower core loss after laser irradiation; the residual shear stress may reduce the effect of the laser irradiation obviously.(4) By laser irradiation on several teams of samples, this paper has studied the better process parameters. The velocity is up to1000mm/s, and the average reduction of this technology is up to7.58%, decreasing the samples’core loss from1.478W/kg to1.35W/kg. According to the better technological parameters in this paper, a model for test equipment has been put forward, and this model can be used for the design of the equipment.(5) Using chemical corrosion and laser irradiation, this paper has studied heat-proof domain refinement technology, and the experimental result is excellent. According to the comparative experiment result, the samples’the core loss treated by this technology can be reduced after annealing, the average core loss is about1.170W/kg, while the average core loss of the samples that didn’t be treated by this technology is about1.261W/kg. so, the domain refinement has heatproof properties, and the average reduction is about7.22%.