Salt-bath furnace quenching method for teeth of chain wheel

Abstract

The invention relates to a salt-bath furnace quenching method for teeth of a chain wheel. The method comprises the following steps of (1) placing a mixture containing BaCl2 and KCl in an intermediate-temperature salt-bath furnace for heating, wherein based on the total amount of 100 parts, the mixture contains 65 to 75 parts by weight of BaCl2 and 25 to 35 parts by weight of KCl, the mixture is heated to be completely melted at the heating temperature of 720 to 940 DEG C, and the melted mixture is the melt of a salt bath; (2) placing the teeth of the chain wheel in the salt bath for heating, wherein the heating temperature of the salt bath is 900 to 920 DEG C, and the heating time is set to be 26 to 30 seconds per millimeter of the tooth thickness of the chain wheel; (3) performing rapid quenching by utilizing a quenching medium after heating and heat preservation; (4) performing tempering heat preservation for 3.5 to 4.5 hours after quenching, and after heat preservation, discharging the teeth of the chain wheel out of the furnace, and air-cooling the teeth. According to the method, a salt-bath furnace quenching process for the teeth of the chain wheel is adopted, so that the hardened layer depth can reach more than 12mm; moreover, hardened layers with different depths can be obtained by regulating the heating time of the salt-bath furnace; the salt-bath furnace quenching process is high in the heating speed and convenient to operate, a workpiece is difficult to oxidize and decarburize, and the temperature is easy to control.

Description

technical field [0001] The invention relates to the field of mechanical manufacturing, in particular to a method for quenching sprocket teeth in a salt bath furnace. Background technique [0002] At present, the surface quenching of the sprocket teeth of the scraper conveyor and the first conveyor of the roadheader adopts flame heating surface quenching. The material of the sprocket is 42CrMo. The surface of the sprocket teeth is heated by acetylene-oxygen flame, and then quenched and cooled. However, this method has the following disadvantages: the depth of the hardened layer of flame heating surface quenching is generally 2 to 6mm, and the depth of the hardened layer required by the sprocket too deep will cause severe overheating of the surface of the steel and cause quenching cracks; After the flame quenching of the tooth part, the surface hardness is uneven, that is, the hardness difference at different points is large, reaching more than HRC10; after the flame quenchin...

AI Technical Summary

Problems solved by technology

[0002] At present, the surface quenching of the sprocket teeth of the scraper conveyor and the first conveyor of the roadheader adopts flame heating surface quenching. The material of the sprocket is 42CrMo. The surface of the sprocket teeth is heated by acetylene-oxygen flame, and then quenched and cooled. However, this method has the following disadvantages: the depth of the hardened layer of flame heating surface quenching is generally 2 to 6mm, and the depth of the hardened layer required by the sprocket too deep will cause severe overheating of the surface of the steel and cause quenching cracks; After the flame quenching of the tooth part, the surface hardness is uneven, that is, the hardness difference at different points is large, reaching more than HRC10; after the flame quenching of the sprocket tooth part, the surface hardened layer depth is uneven, that is, the depth of the hardened layer at different points There is a large difference, up to 3mm or more; the shape of the sprocket teeth is complex and there are many types of sprocket specifications, and the requirements for quenching machine tools are relatively high. Generally, imported equipment is used, and the required equipment costs are relatively large; the shape of the sprocket teeth is complex. The use of manual operation requires a high level of operation and experience for workers, and the labor intensity is relatively high.