Heat treatment of crane wheels

Crane wheels are generally forged by forging. Small size wheel forgings are also useful forging steel manufacturing, generally not less than 45 high quality steel. Crane wheels with large loads made of alloy steel, some crane wheels to reduce the wheel diameter to reduce the height of the crane, there are also alloy steel materials used in the production of crane wheels.

GB6067-1985 when the rim thickness wear up to 50% of the original thickness should be scrapped. Crane Design Manual, pointed out that the crane wheel rim to bear the lateral pressure of the crane, the wheel has 70% -80% of the trip to the side of the track with the friction, due to wear and tear of the wheel rim and make the wheel scrapped. Therefore, in the heat treatment of the wheel, should also be included in the inner side of the rim. Such as industrial frequency quenching, heating induction circle is too narrow, the hardness of the inner side of the rim will not meet the requirements.

GB6067-1985 when the crane wheel tread thickness wear up to 15% of the original thickness should be scrapped. In the manufacturing process, both to make the tread hardness moderate (too high will make the track serious wear), but also to make the crane wheel tread depth at 20mm to meet the requirements (too low will make the crane wheel serious wear), is somewhat difficult. According to many years of experience, when the carbon content of less than 0.5% of cast steel or ordinary carbon steel materials, crane wheel tread depth of hardened layer will not meet the requirements.

Crane wheel heat treatment if the use of surface group flame quenching method, this method of hardened layer depth of only 2-5mm, and the surface brittleness is very large, in the process of operation, the crane wheel tread cracking, and then hardened layer off, resulting in the scrapping of the wheel, this method should not be used.

In order to improve the bearing capacity and service life of crane wheels, crane wheel forging tread must be heat-treated, heat treatment requirements and the inner side of the wheel tread hardness: 300-380HB, the depth of the hardened layer of 20mm at not less than 260HB In the current technical conditions, the use of a variety of heat treatment methods can achieve the above requirements.