Forged steel cold rolling roller cryogenic treatment method and novel nozzle adopted by same

Abstract

The invention discloses a forged steel cold rolling roller cryogenic treatment method and a novel nozzle adopted by the same. The nozzle is provided with a mounting part and a nozzle head, wherein thenozzle head is provided with a large nozzle port with the diameter of 0.8 mm to 1.2 mm and a plurality of small nozzle ports provided with the diameters of 0.4 mm to 0.6 mm and arranged on the periphery of the large nozzle port. The cryogenic treatment method comprises the following steps that (1) a forged steel cold rolling roller is placed in a cryogenic box, and the cryogenic box is closed; (2) liquid nitrogen is sprayed into the cryogenic box from the nozzle, and the temperature in the cryogenic box is lowered to -160 DEG C to -120 DEG C through 1 h to 2 h; (3) the temperature is kept for 2 h to 5 h at the temperature; and (4) after keeping of the temperature is finished, the cryogenic box is opened, and the forged steel cold rolling roller is placed under a room temperature environment to be naturally restored to the room temperature. According to the forged steel cold rolling roller cryogenic treatment method and the novel nozzle adopted by the same, the novel nozzle is designed, and the corresponding cryogenic treatment method is adopted for matching so that the sprayed liquid nitrogen can be more dispersed and more uniform, so that the surface hardness of the forged steelcold rolling roller is more uniform, the hardness uniformity of the finished product is improved, and the blockage phenomenon of the nozzle is also greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of cryogenic treatment, and in particular relates to a method for cryogenic treatment of forged steel cold rolling rolls and a novel nozzle adopted therefor. Background technique [0002] The forged steel cold roll is the most important part of the cold rolling mill. Most of the cold rolls will be subjected to cryogenic treatment during the manufacturing process. It is an extension of the cooling process of the cold roll heat treatment. The cryogenic treatment is to place the cold roll at a specific low temperature. Change the microstructure in the environment to achieve the purpose of improving the comprehensive performance of cold rolling rolls. [0003] At present, the cryogenic treatment of forged steel cold rolling rolls mainly adopts the direct spraying method of liquid nitrogen. The cryogenic treatment equipment mainly includes: liquid nitrogen storage tanks, cryogenic boxes, liquid nitrogen nozzles a...

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Problems solved by technology

[0004] At present, the problem existing in the liquid nitrogen direct spray cryogenic treatment method is that the hardness uniformity of the finished product is poor. After a lot of research, the applicant found that this problem has a lot to do with the existing structure of the liquid nitrogen nozzle.

The liquid nitrogen ejected from this nozzle is relatively concentrated, and the cooling intensity is relatively high, which will cause the temperature of the local area of ​​the forged steel cold roll to be low, resulting in soft bands or even cracks, and it is also prone to nozzle clogging

[0006] Chinese patent document CN103468918A installs a net cover at the nozzle of the liquid nitrogen nozzle so that the sprayed liquid nitrogen is in the form of a fine mist. However, this technical means cannot solve the above problems well.

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