A device for liquid nitrogen injection experiments with double nozzles that improves quenching speed easily

Abstract

The invention discloses a double-nozzle liquid nitrogen injection experiment device for simply and conveniently improving the quenching speed. The device comprises liquid nitrogen supply sources, theliquid nitrogen supply sources are connected with liquid nitrogen spray heads through liquid nitrogen conveying pipes, the liquid nitrogen spraying heads are arranged on the left side wall and the right side wall of a liquid nitrogen injection working chamber in a bilateral symmetry mode, and a sample clamping device and an induction heating device are arranged inside the liquid nitrogen injectionworking chamber. According to the device, the key components such as the induction heating device, the liquid nitrogen supply sources, a flow control unit, the liquid nitrogen conveying pipes, the liquid nitrogen injection working chamber, the sample clamping device and a temperature measuring thermocouple are skillfully designed and reasonably arranged, so that multiple aspects such as the liquid nitrogen flow rate, the flow rate, the cold speed measurement and the spraying uniformity can be accurately controlled correspondingly, and meanwhile, the problems that the cooling measuring speed and the quenching cooling speed are not enough, and the uniformity is poor can be solved.

Description

technical field [0001] The invention relates to a device for liquid nitrogen spraying experiments, in particular to a device for liquid nitrogen spraying experiments with double nozzles which can easily improve the quenching speed. Background technique [0002] With the continuous development of material science and engineering technology, a large number of scientific and technological workers are committed to exploring the influence of the microstructure of materials on the mechanical properties of materials. For the widely used martensitic steel, its microstructure is relatively complex, and the scale and shape of the microstructure have a significant impact on the mechanical properties of martensitic steel. In order to explore the influence of martensitic structure on the mechanical properties of martensitic steel, the method commonly used at present is to adjust the morphology and microscopic size of martensitic structure by changing the heat treatment process parameters...

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Problems solved by technology

In order to obtain a fine martensite structure, it is necessary to increase the cooling rate in martensite quenching. As we all know, the cooling rate of liquid nitrogen is quite high, but if the sample is directly immersed in liquid nitrogen, the surface of the sample will be damaged due to the volatilization of liquid nitrogen. The nitrogen film is formed, and the nitrogen film shields the heat exchange, which is not conducive to increasing the cooling rate. Therefore, in order to improve the heat exchange of liquid nitrogen on the quenched sample and increase the cooling rate as much as possible, it is necessary to design a reliable test device , an experimental device that ensures the cooling uniformity of the sample during the cooling process while obtaining an extremely fast cooling rate

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