Heat treatment of forged steel grinding balls
Steel ball heat treatment is a process in which the billet is heated to a certain temperature in a specific environment and maintained for a certain time, and then cooled at different speeds. The heat treatment process generally includes three processes of heating, insulation and cooling, but sometimes there are only two processes of heating and cooling, and these processes are interconnected and uninterrupted.
heat treatment steps of grinding balls
Heating is one of the important processes of heat treatment, in which the heating temperature is an important parameter of heat treatment process, and the selection and control of heating temperature is the main problem to ensure the quality of heat treatment. The heating temperature varies with the steel ball material being treated and the purpose of heat treatment, but it is generally heated above the phase change temperature to obtain high temperature microstructure. In addition, the transformation takes a certain amount of time, so when the surface of the forged steel grinding balls workpiece reaches the required heating temperature, it must also be maintained at this temperature for a certain time, so that the internal and external temperature is consistent, so that the microstructure is completely transformed, this period of time is called the holding time. When high energy density heating and surface heat treatment are used, the heating speed is extremely fast, and there is generally no holding time, and the holding time of chemical heat treatment is often longer.
Cooling is also an indispensable step in the heat treatment process, and the cooling method varies according to the process, mainly to control the cooling speed. Generally, the cooling rate of annealing is the slowest, the cooling rate of normalizing is faster, and the cooling rate of quenching is faster. However, there are different requirements due to different types of steel, for example, air-hard steel can be hardened with the same cooling rate as normalizing.
influence of heat treatment
Heat treatment in the field of forged steel grinding balls is an important factor affecting the quality of the grinding ball, high-quality wear-resistant steel balls should not only have excellent surface hardness, but also have good performance in volume hardness, hardness uniformity and toughness. Maanshan Yongxing New Material Technology Company introduced advanced technology from Spain, and jointly with experts from scientific research institutions, developed a unique composite heat treatment process, through multiple quenching temperature control, continuous tempering, effective annealing and other processes, so that the steel ball has a good performance in the uniformity of volume hardness and overall wear resistance.