High-temperature bluing method of long and large part

Abstract

The invention discloses a high-temperature bluing method of a long and large part, which comprises: placing a support on the bottom of a bluing tank, determining a preset bluing temperature and preset bluing time, preparing bluing solution, aging the bluing solution, preheating the washed long and large part, placing the preheated part on the support for bluing, setting the temperature of the bluing solution when the part enters the tank at the highest value of the preset bluing temperature, taking the part out of the tank slowly after the bluing is finished, washing the surface of the part with at least three water heads at the same time, transferring the part to a clear water tank after the part is taken out of the tank completely, washing off the alkaline bluing solution on the surfaceof the part completely, placing the long and large part washed completely by clear water on a wooden sleeper with a wrapping cloth pad, checking the long and large part, and applying oil onto the long and large part is the long and large part is qualified. The method has the advantages that: the structure is simple; the operation is simple and the washing effect is good; and a high-quality blued film can be formed on the long and large part conveniently, and the blued film is more compact, firmer and more alkaline corrosion resistant.

Description

technical field [0001] The invention relates to a high-temperature bluing method, in particular to a high-temperature bluing method for long parts, and is particularly suitable for high-temperature bluing of long parts with a length of more than two meters. Background technique [0002] Bluing refers to the material protection technology that heats steel in the air or directly immerses it in a concentrated oxidizing solution to produce a very thin oxide film on the surface, also known as blackening. The blueing of steel parts can be carried out in the molten salt of sodium nitrite and sodium nitrate, or in high temperature hot air and superheated steam above 500 ° C, more commonly used in concentrated caustic soda with sodium nitrite heating. The solution composition, reaction temperature and time when turning blue depend on the composition of the steel matrix. The composition of the blue film is magnetic iron oxide, the thickness is 0.5-1.5 microns, the color is related t...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the defects and problems existing in the prior art that the bluing quality of long parts is poor and alkali corrosion is easy to occur, and to provide a kind of bluing quality of long parts that is good and not prone to alkali High temperature bluing method for long parts with corrosion phenomenon