Hardness of shredder blade

Hardness is a very important technical parameter in the manufacturing process of the shredder blade. The tool with insufficient hardness is very easy to wear in the crushing production, which affects the efficiency of the crushing process. Therefore, how to control the hardness of the shredder blade and prevent the outflow of the tool with insufficient hardness becomes the top priority in the production of the shredder blade.

At present, the heating furnace for heat treatment generally adopts the computer temperature control system, and the shredder blades should be placed evenly at reasonable intervals during furnace loading. Stacking heating is easy to cause uneven heating, resulting in high quenching temperature. This is caused by improper process setting temperature or temperature control system error, and the quenching temperature should be corrected. At the same time, after the shredder blade is quenched, tempering can ensure the toughness of the tool and reduce the occurrence of the crack caused by internal stress. However, excessive tempering will make the temperature of the tool become low, and the hardness of the originally qualified tool will be changed to unreasonable hardness. This is the error occurred during tempering operation. Once this problem occurs, it can be re-quenched to ensure the hardness of the tool.

Analyze the heat treatment process of the shredder blade. Improper cooling during quenching, long pre-cooling time and improper selection of cooling medium are all the reasons for the decline of the tool performance. To solve these problems, attention should be paid to the speed of discharging and entering the groove during quenching; Master the cooling characteristics of quenching medium; The oil temperature is 60~80 ℃, and the water temperature is below 30 ℃. When the quenching volume is large and the cooling medium is heated, the cooling quenching medium should be added or other cooling bath should be used for cooling. After that, decarburization is also one of the important reasons for tool quenching production, which is caused by the failure of the residual decarburization layer of the raw material to be treated in time, and the failure of the tool to reach the agreed stability during quenching and heating, resulting in the unqualified heat treatment hardness of the broken crusher blade.