Continuous production method for solid powder chromizing

Abstract

The invention discloses a continuous production method for solid powder chromizing. The continuous production method comprises the following steps that (1) a workpiece is pre-buried in a powdery chromizing agent and contained in a load bearing box; and (2) chromizing treatment: the load bearing box filled with the workpiece and the chromizing agent is conveyed into a high-temperature furnace froma workpiece inlet through a conveying mechanism, the load bearing box sequentially passes through a heating zone, a heat preservation zone and a cooling zone of the high-temperature furnace and then is sent out from a workpiece outlet to complete chromizing treatment, protective gas is introduced into the high-temperature furnace, the flowing direction of the protective gas is opposite to the moving direction of the workpiece, the content of oxygen in the heat preservation zone is lower than 100 PPM, and the dew point is lower than -35 DEG C. According to the continuous production method for solid powder chromizing, the chromizing process is improved for the defects of the existing process, so that continuous production of chromizing can be realized; therefore, compared with the difficultyof the existing sealed processing, the processing difficulty is greatly reduced, the equipment requirement is low, the production efficiency is improved, the high-temperature furnace does not need tobe repeatedly heated and cooled to cause a large amount of loss of heat energy, the environment is protected, energy is saved, the processing cost is about 1 / 5-1 / 8 of that of the sealed processing, and the application range of chromizing products can be greatly expanded.

Description

technical field [0001] The invention relates to the field of metal surface treatment, in particular to a continuous production method for solid powder chromizing. Background technique [0002] In order to improve the heat resistance, corrosion resistance and oxidation resistance of metals, and increase the durability and fatigue strength, metal parts such as steel parts are heated in a chromizing medium, and the new active chromium penetrates into the surface of the steel part, making the surface of the steel part with Corrosion and heat resistance, so that common steel can be used instead of more expensive stainless steel. [0003] The existing chromizing processes include solid powder chromizing, gas chromizing, salt bath chromizing, etc. Taking the most commonly used solid chromizing as an example, since the content of oxygen and water in the chromizing environment in the furnace needs to be controlled, it is basically static and sealed. [0004] Usually the solid chrom...

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Problems solved by technology

[0005] Due to the limitation of the sealed environment, this kind of process cannot realize the continuous processing of the workpiece. The workpiece can only be released after the whole furnace is heated to a high temperature and then cooled down. The whole process takes a long time, which is very unfavorable for energy saving and environmental protection. Huge, resulting in a processing cost of more than 24,000 yuan per ton of workpieces. At present, it is generally only used in parts with high product requirements in the fields of military industry, aerospace, navigation, and automobiles, which greatly limits the use of chromizing treatment on other products. application

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