Method and device for accelerating powder method boronisation by alternating-current filed

Abstract

The invention discloses a method and a device for accelerating powder method boronisation by an alternating-current filed and used for strengthening the surface of a metal part. Two parallel plate-shaped electrodes are placed in powdered boronizing agent and by leads, the two electrodes are respectively connected on a 50Hz alternating current power supply of which the voltage is continuously adjustable within the range of 0-250V; a treated part is positioned between the two electrodes; the electrodes and the part are sealed together with the boronizing agent in a boronisation box and placed in a heat treatment furnace to heat; after the temperature of the furnace achieves a set value, appropriate alternating voltage is applied between the two electrodes; and then the rapid boronisation of the part can be realized. Compared with the existing method, the method of the invention has the advantages that the boronisation can be accelerated by at least 0.3-3 times and the usage amount of the boronizing agent is reduced by above 70%. Therefore, the method and the device can accelerate the powder method boronisation of the metal part, improve the utilization rate of the boronizing agent, lower the temperature of boronisation and reduce deformation of the part.

Description

technical field [0001] The invention belongs to a method and a device for chemical heat treatment on the surface of a metal part, in particular to a method and a device for boronizing by an AC electric field accelerated powder method for strengthening the surface of a metal part. Background technique [0002] Boronizing is a chemical heat treatment process that infiltrates boron into the surface of metal workpieces. The boronizing layer has high hardness and wear resistance, as well as certain high-temperature oxidation resistance and corrosion resistance, so boronizing parts have a wide range of applications. Boronizing can be divided into solid, salt bath, electrolytic and vapor phase boronizing methods. [0003] At present, the most widely used solid powder method boronizing (referred to as powder method boronizing) is generally high-temperature boronizing at 850-950°C according to the performance requirements of the parts and the material of the parts. The commonly used...

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Problems solved by technology

[0004] The boron donors such as boron carbide and ferroboron used in the current process are expensive, but only part of the reaction is consumed in one boronizing treatment

In order to overcome the problem of low utilization rate of boron supplying agent, at present, it is generally used to add activator and infiltration catalyst to the old boronizing agent, and then use the boronizing agent in an appropriate proportion to increase the boron supplying agent. The utilization rate of the boronizing agent, but due to the decomposition products of some activators and infiltrating agents in the boronizing agent, the infiltration agent is compacted. The more repetitions, the more serious the compaction. The use of old infiltration agents will increase the difficulty of cleaning the parts after infiltration, and will also affect The surface quality of the parts, it is not suitable to use the old penetrating agent for multiple times

[0005] In addition, the generation of active boron atoms in the current solid powder boronizing is caused by the thermal decomposition and mutual reaction of the infiltrating agent under the action of high temperature. In order to increase the penetration rate and obtain a thick penetration layer, the current process adopts high temperature, high proportion of boron supply agent, adding penetration accelerator, prolonging the holding time, etc., not only the utilization rate of penetration agent is not high, At the same time, there are disadvantages such as high processing temperature, long processing time, and high cost.

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