Method for keeping surface color of heated bearing part uniform

Abstract

The invention discloses a method for keeping the surface color of a heated bearing part uniform, which is based on a quenching salt bath and quenching heating furnace integrated roller hearth furnace salt quenching production line with a nitrogen-based protective atmosphere. Through increasing the cleaning degree of a workpiece, improving the purity degree of quenching salt bath, strengthening the control on the nitrogen-based protective atmosphere in the furnace and selecting a reasonable oxygen potential control parameter of an oxygen probe, the atmosphere in the furnace is controlled within a relatively reasonable level, so that the workpiece is neither decarburized nor oxidized, and the color of the workpiece is kept uniform. By applying the method, a shot blasting or sand blasting process of the workpiece can be reduced, the goods delivery speed of the heated bearing part can be increased, and the demands of users can be met. The invention provides a novel workpiece surface quality control method by which the color of a non-contact surface in a thermal treatment process of a bearing part is uniform and is changed from the original blue graniphyric into uniform dark blue.

Description

technical field [0001] The invention relates to the technical field of heat treatment of bearing steel bearing parts, in particular to a method for ensuring that the surface color of the heated parts of the bearing parts is consistent, so as to obtain a satisfactory surface color of the heated parts. Background technique [0002] At present, the domestic bearing industry adopts the more advanced roller hearth furnace salt quenching heat treatment production line. With the update of thermal processing equipment in the bearing industry, this type of equipment is one of the most widely used equipment in the bearing heat treatment industry. The quenching and tempering heat treatment of large, medium and small high-carbon chromium bearing steel bearing parts with a diameter of less than 750mm can be realized in the salt quenching production line of the roller hearth furnace. The products currently manufactured have achieved non-oxidation and non-decarburization heating of the wor...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for ensuring the consistent surface color of bearing parts after heating, in order to solve the problem that the appearance color of the workpiece surface is inconsistent and the color of the bearing parts is inconsistent after the quenching, heating and cooling of the roller hearth furnace salt quenching production line in the nitrogen-based protective atmosphere. Spot phenomenon, without increasing the shot blasting or sandblasting process, so that the appearance of the workpiece surface is uniform in color