Selection of 65Mn and CL60 wheel forgings for cranes

Wheel forgings are important parts of the crane travel mechanism, rolling on the track at low speed and bearing the load of the crane's own weight and lifting weight. The working characteristics of crane wheels are low speed and heavy load, therefore, the material of wheel forgings should have strength, hardness, and good wear resistance. There are three types of crane wheels: cast steel, forged and rolled. Early crane wheels are basically cast steel wheels, and in recent years forged and rolled wheels are commonly used.

At present, the material of forged wheels usually uses 65Mn and CL60, today we introduce the analysis of the two materials commonly used in cranes for comparison. Crane forging wheel material is usually used 65Mn and CL60, for crane wheel work characteristics, the wheel on the chemical composition of the material and mechanical properties have certain requirements.

CL60 steel material strength, hardness and elasticity are very high, cold deformation when the plastic shape is low, more suitable for high-speed operation of the wheel, crane wheels in the process of operation, requiring higher strength, wear resistance and a certain elasticity, so that CL60 do wheel forgings is a more suitable material.

65Mn is a high-quality carbon structural steel, is commonly used spring steel materials, the steel strength, hardness, elasticity and hardenability are higher than the general steel. The heat treatment of crane wheels is usually quenched + tempered, and the organisation is tempered taustenite, which has a high elastic limit and yield limit, and a certain toughness. 65Mn has the above advantages and is cheap and easy to procure, and is suitable for crane applications.

From the chemical composition of both, 65Mn has more of the chemical elements manganese, chromium, nickel and copper. Manganese as the main metal element to provide hardenability, is the material surface decarburisation tendency is small, the mechanical properties of the material after heat treatment is better. In addition, most of the manganese dissolved in the ferrite, the formation of replacement solid solution, and make the ferrite reinforced, part of the manganese special dissolved in Fe3C, the formation of alloy carburized body. Manganese can also increase the relative amount of pearlite and make it thin, thus improving the strength of steel; manganese can be combined with S to become MnS, to reduce the harmful effects of S. In addition, the increase of elements such as chromium can refine the carbide, improve the hardenability and tempering stability, and improve the strength. Therefore, it is better to use 65Mn material for crane wheels.