Method and device for optimizing surface residual stress of metal part based on electromagnetic induction heating and rapid surface cooling

Abstract

The invention discloses a method and device for optimizing surface residual stress of a metal machined part based on electromagnetic induction heating and rapid surface cooling, and belongs to the field of machining. According to the method and the device, a part is slowly heated in an electromagnetic induction heating mode, so that internal temperature distribution of the part is relatively uniform and plastic deformation of a local material due to too large temperature gradient is avoided; and after the part is slowly heated to certain temperature, the outer surface of the part is rapidly cooled through liquid nitrogen, the outer-layer material is sharply contracted in cold, meanwhile, tensile stress is generated due to the blocking effect of the inner-layer material, the outer-layer material is subjected to tensile plastic deformation to increase the size, the part is continuously cooled to normal temperature, the part is subjected to the compression effect of the inner-layer material due to the increase of the surface material, and finally, residual compressive stress is formed on the outer-layer material. Therefore, the fatigue life of the part is prolonged, and the corrosionresistance and other properties of the part are improved.

Description

Technical field: [0001] The invention relates to a method and device for optimizing the surface residual stress of metal parts based on electromagnetic induction heating and rapid surface cooling, which belongs to the field of mechanical engineering. Background technique: [0002] With the rapid development of the industrial field, its requirements for the processing quality and reliability of machined parts are also getting higher and higher. For metal processing parts, the distribution of surface residual stress will seriously affect the fatigue life, corrosion resistance and crack resistance of the parts. How to effectively optimize the distribution of residual stress on the surface of metal processing parts so that its The improvement of performance in many aspects is a problem that the manufacturing industry and related scientific researchers have been working hard to solve. The traditional method mainly includes two aspects: optimization during the machining process a...

AI Technical Summary

Problems solved by technology

The traditional method mainly includes two aspects: optimization during the machining process and subsequent optimization. The optimization during the machining process mainly considers the optimization of machining parameters, such as changing cutting parameters, using strict coolants and specific tools, etc., and the corresponding optimization process It is difficult to balance processing efficiency and processing surface quality (such as roughness, etc.) at the same time. Not only that, too harsh coolant will greatly increase the corresponding manufacturing cost; subsequent optimization is mainly to optimize the corresponding stress distribution after the previous manufacturing is completed. The optimization process mainly includes shot peening, ultrasonic impact, nitriding, carburizing, etc. Although shot peening and ultrasonic impact methods can significantly improve the residual stress distribution on the surface of the part and obtain a large residual compressive stress, the corresponding treatment will be The surface roughness of parts has a serious impact, which is often not suitable for high-precision occasions, and nitriding and carburizing often have little effect on improving the surface residual stress, and sometimes it can be said to be negligible, and even pollute the environment , and the current ultrasonic vibration aging treatment can greatly reduce the residual compressive stress inside the part, but it cannot form a large residual compressive stress distribution at all. It can be said that its optimization effect is very limited, and it can only reduce harmful stress, but cannot form a favorable stress. stress

[0003] Due to the joint action of many factors during the manufacturing process of traditional metal parts, residual tensile stress is often formed on the surface of the part, which will have an important negative impact on the fatigue life and corrosion resistance of the part

[0004] For processed metal parts, there is a need for an optimization method that is low-cost, high-efficiency, non-polluting and will not negatively affect the surface accuracy of the parts. There is no corresponding solution in the current technical field

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