On 2018-08-08 14:48:54
Common defects of high cycle quenching heat treatment
The common defects of high cycle quenching heat treatment are quenching crack, soft spot and peeling. High cycle quenching is more afraid of overheating in local areas due to uneven heating, such as sharp corners of the workpiece, keyways and the surrounding of holes, which are very easy to cause overheating, leading to the occurrence of quenching cracks. The above situation can be reduced by filling copper to reduce the possibility of quenching cracks. In addition, the non-uniform quenching process of the high frequency quenching workpiece will cause the low surface hardness of the workpiece, which is called the soft spot. This phenomenon is caused by the non-uniform quenching temperature of the high frequency quenching, the blocking of the spray holes or the improper size and number of holes. The third kind of defect is the phenomenon of surface peeling. The main reason is that the hardness of the section changes greatly or the hardening layer is too shallow. Therefore, preheating is often used to deepen the hardening layer, which can effectively prevent peeling.
High cycle quenching heat treatment
Hot air circulation mechanism: the furnace is equipped with a fan device, which is placed on the top of the furnace body, and the fan is made of heat-resistant steel into a circulation fan blade. The heat produced by the heater is heated to the workpiece by the fan without any gap, so that each part of the workpiece is evenly heated, and the phenomenon of workpiece processing dead point is eliminated.
Electric heating device: it adopts stainless steel jacket and high resistance alloy heating wire type heating pipe, which is installed on both sides of the furnace lining. It adopts advanced plug-in structure, which has high radiation efficiency, strengthens the heat exchange in the furnace, improves the thermal efficiency of the furnace, enhances the service life, and is very convenient for installation and maintenance.
After the casting is completed, it is usually necessary to temper the casting according to the material of the casting, which has reached the required material properties and achieved the effect of stress relief. Tempering is a process of heating the cooled castings. The quality of the castings is directly determined by the heating effect of tempering. Usually, the tempering furnace is a container equipment made of refractory materials, which uses coke, gas or electricity as the heating source to place the casting in the furnace for heating.
Oil bath tempering furnace is a kind of heat treatment furnace which uses oil as the medium to temper parts. It mainly includes oil tank and material frame which is located in the oil tank to place parts. The oil in the oil tank is heated and the heat is transferred to the parts through the material frame to complete tempering of parts. The problems existing in the existing oil bath tempering furnace are: the parts are stationary in the container during tempering, uneven heating, and poor tempering consistency; after tempering, the lifting frame is used to filter the oil above the oil tank, occupying the driving vehicle, which also brings safety hazards and high labor intensity to the operator; the oil smoke of the existing furnace is large, which is not conducive to environmental protection and health.