Single side type capacitor sensor for nitrogen potential measurement in metal nitriding process

Abstract

The single-side capacitive sensor coverts the liquid level into capacitance value expressing the ammonia decomposing rate. It includes cylindrical container with coated conducting layer and probe inserted to the lower part of the container slantwise, and there is insulating layer between the probe and the container wall. The container has gas inlet pipe and water inlet pipe in upper part, water draining pipe in the bottom, valves in the gas inlet pipe, the water inlet pipe and the water draining pipe, and electrode leads connected to the conducting layer and the probe. The single-side capacitive sensor of the present invention has the features of: convenient use, accurate measurement in ammonia decomposing rate parameter, optional container structure and material, low cost, simple structure, etc.

Description

technical field [0001] The invention relates to a sensor for nitrogen potential measurement in metal nitriding process. Background technique [0002] Metal nitriding can improve the surface hardness, wear resistance, fatigue strength and corrosion resistance of steel parts. Metal nitriding treatment is that ammonia gas decomposes into active nitrogen at the decomposition temperature and penetrates into the surface of the workpiece. The control parameters of the nitriding process include decomposition temperature, treatment time and nitrogen potential. In the traditional metal nitriding process, the decomposition rate of ammonia gas is used to characterize the nitrogen potential parameter. [0003] A simple measurement method for the decomposition rate of ammonia gas is to use the high solubility rate of ammonia gas in water. Fill the glass container with the exhaust gas in the reaction furnace, close the container so that the container is only co...

AI Technical Summary

Problems solved by technology

This method requires workers to read V1 and V2 from the container to obtain the ammonia decomposition rate, and for continuous long-term heat treatment processes, manual measurement is often unreliable

At present, although there are hydrogen sensors that use the difference in thermal conductivity between hydrogen and ammonia to measure the decomposition rate of ammonia from the output electrical signal, the use of platinum electrodes affects the decomposition of ammonia and is expensive.

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