A device for measuring the thermal history curve of the melt in the pulse current liquid level disturbance solidification fine-grain process

Abstract

The invention relates to a device for measuring the thermal history curve of a melt in a pulse current liquid level disturbance solidification fine-grain process, which belongs to the technical field of material processing. The device mainly includes a pulse power supply, parallel electrodes, heating wires, lifting rods, ceramic tubes and plugs; the heating wires are connected to 220V alternating current through the plugs, the parallel electrodes are connected to the pulse power supply, and a casting mold filled with metal blocks is placed on the lifting rods; The wire heats up to melt the metal block; then the lifting rod rises to insert parallel electrodes into the metal melt, and apply pulse current to the liquid level to disturb the treatment; at the same time, the thermocouple is also inserted into the melt and fixed, and the thermal history curve of the melt is measured. Compared with the traditional temperature measuring method, the present invention saves the pouring process, can measure the thermal history curve of the melt more stably and accurately, and provides reliable thermal historical data of the melt for the pulse current liquid level disturbance solidification fine-grain process.

Description

technical field [0001] The invention belongs to the technical field of material processing, and in particular relates to a device for measuring the thermal history curve of a melt in a pulse current liquid level disturbance solidification fine-grain process. technical background [0002] In modern society, the vast majority of metal parts are processed by casting blanks or metal ingots. Although the structure of the metal can be greatly changed in the subsequent reprocessing process to optimize its performance, the metal is solidified The microstructure characteristics formed in the process still have a great influence on the subsequent processing and final material properties. Therefore, controlling the solidification process and solidification structure of metal materials has always been the focus of research by material workers, and grain refinement can significantly improve the performance of castings. One of the most effective methods for metal solidification. In the e...

AI Technical Summary

Problems solved by technology

In order to further explore the essential mechanism of the fine-grain method, it is of great significance to accurately measure the thermal history curve when the melt is solidified under the action of the fine-grain method. Melt and hold for a certain period of time, and then pour the molten metal into the mold. During the period from taking the molten metal out of the resistance furnace to pouring, the molten metal dissipates heat in the air, resulting in its temperature already rising when it is poured into the mold. and the height and position of the gate and the way of filling the molten metal also have a significant impact on the temperature distribution in the melt, and these methods are difficult to keep consistent in the process of each pouring; in addition, in the traditional temperature measurement method There are two main methods for inserting thermocouples: one is to drill holes from the side wall of the mold and embed the thermocouples horizontally in advance. Large, the cooling speed is very fast, so the measured temperature has a large error, and there is a danger of the melt leaking from the thermocouple socket

The second is to insert the thermocouple into the melt after pouring is completed, and when the molten metal is poured into the mold with a relatively low temperature, a solidified shell will quickly form on the mold wall, and the re-inserted thermocouple will also affect the mold. The melt in the area produces a certain chilling effect, and these two factors lead to a large deviation in the measured temperature compared to when the pouring is just completed

In summary, it is difficult to accurately obtain the temperature of the melt in the pulse current liquid level disturbance solidification fine-grain process by using the device in this patent

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