Rapid salt-bath nitridation method by applying magnetic field

Abstract

The invention relates to a rapid salt-bath nitridation method by applying a magnetic field. The method comprises the following steps: washing, pre-oxidizing, melting nitridation basic salts, applying a magnetic field to carry out nitridation, and washing. The method has the advantages that under the effect of a magnetic field, domain rotation and domain wall displacement are generated around the material surface, the exchange energy and anisotropy energy are increased, and the nitrogen atom diffusion is accelerated; magnetization happens near the surface of workpiece, magneto-striction is generated then, the strain energy is increased, and the diffusion of nitrogen atom is accelerated; active nitrogen atoms diffuse on the material surface under the effect of the magnetic field, the surface adsorption and diffusion are accelerated, the penetration is promoted and accelerated, the salt-bath nitrogen penetration time is reduced, the energy is saved, and the environment is protected; the hardness and surface wear-resistant performance of a sample is improved, the excellent surface corrosion resistant performance of the sample can be preserved; in the provided method, people can obtain a nitrogen penetration layer with the same thickness as that of a nitrogen penetration layer, which is produced by a common salt-bath nitrogen penetration method, by low-temperature heating, thus the energy is saved, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of metal surface modification, and in particular relates to a method for rapid salt bath nitriding by applying a magnetic field. Background technique [0002] Salt bath nitriding technology is a metal surface chemical heat treatment technology. Ordinary carbon steel nitriding can be used to replace high-alloy tool steel, stainless steel or other special alloys in the environment, so it has very important engineering application value. [0003] The salt bath nitriding treatment technology is simple in operation, low in cost, easy to control in process, and good in quality of the nitriding layer. But the disadvantage is that in practical application, in order to increase the thickness of the infiltration layer on the surface of mechanical parts, it is necessary to increase the salt bath nitriding temperature and holding time, resulting in a great energy consumption and reducing production efficiency. To this...

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Problems solved by technology

But the disadvantage is that in practical application, in order to increase the thickness of the permeated layer on the surface of mechanical parts, it is necessary to increase the salt bath nitriding temperature and holding time, resulting in a huge energy consumption and reduced production efficiency

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