Medium frequency induction welding method of rail

Abstract

The invention discloses a medium frequency induction welding method of a rail. The medium frequency induction welding method is characterized by comprising the following steps: 1. a rail to be welded is clamped by utilizing a gas pressure welding clamping machine; the end surface area to be welded of the rail to be welded is heated by a medium frequency inductor; in the heating process, an infrared thermometer is used for detecting whether the heating temperature of the end surface area to be welded reaches a welding upsetting initial temperature or not; and the medium frequency inductor is connected with a medium frequency power source and a water cooling system; and 2. the welding upsetting of the rail to be welded is realized. Through the medium frequency induction welding method disclosed by the invention, in a welding process, the welding upsetting temperature is accurately controlled; the interference of anthropic factors on the welding quality is eliminated to a maximum extent; the stability is high; foundry defects and flash welding ash spots are not generated; and when the welding quality is guaranteed, the automatic flow line production is conveniently realized and the welding production efficiency is favorably improved.

Description

Technical field [0001] The invention relates to a steel rail welding technology, in particular to a steel rail intermediate frequency induction welding method. Background technique [0002] In the rail welding technology, the requirements for the mechanical properties, geometric accuracy and quality stability of the weld are very high, and the quality of the welding seriously affects the service life of the rail. At present, there are four main welding methods for rails: [0003] 1. Thermite welding: use thermite reaction heat as a heat source to make the thermite flux into liquid metal, and inject sand to form weld metal. Since the weld is a cast welded structure, there are unavoidable casting defects such as porosity, inclusions, slag inclusion, and shrinkage. Its mechanical properties are much lower than that of the rail base material, and the plasticity and toughness of the weld are low. [0004] 2. Flash welding: When the current passes through the contact surfaces of the two ...

AI Technical Summary

Problems solved by technology

However, there are gray spots in the weld structure in flash welding, which cannot be avoided. When the area of ​​gray spots exceeds a certain level, the welding head will be scrapped and the mechanical properties of the weld will be seriously reduced; in addition, the welding power required by flash welding is high, and the welding machine cost Very high (take GAAS80 fixed welding machine as an example, its cost is about 12 million, plus the total price of accessories is as high as 17 million), once the welding machine breaks down or needs to replace accessories, it will cause great losses and seriously affect production efficiency

[0005] 3. Arc welding: a welding method that uses an arc as a heat source to melt the electrode metal and fill it to form a weld. It has a high degree of manual work, low production efficiency, difficult quality control, and poor stability.

[0006] 4. Gas pressure welding: use oxygen and acetylene flame to heat the rail to a plastic state, use a gas pressure welding crimping machine to clamp the rail to be welded and apply upsetting pressure to complete the welding, although there is no casting defect at the weld and no flash welding ash However, due to the interference of the flame, it is difficult to accurately measure and control the temperature of the rail, so it is impossible to determine the best upsetting time by accurately measuring the temperature of the weld to ensure the quality and stability of the weld, and the welding quality is relatively high The degree depends on the operator's experience, the influence of human factors is greater, and the welding efficiency is low

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