Large forgings are generally used in the key parts of large machinery. Due to the harsh working environment and complex and changeable forces, the quality requirements of large forgings are very high in the production process. The forging of large forgings should not only meet the required shape and size of the parts, but also the important thing is to break the cast tissue, refine the grain, uniform tissue, forging shrinkage cavity, porosity and shrinkage porosity, and improve the internal quality of forgings. The larger the ingot size, the more serious the defects in the ingot, and the more difficult it is to improve the defects in forging, thus increasing the difficulty of forging. In the forging process, upsetting and drawing are the basic and indispensable processes. For forgings with special shapes, tire die forging is also commonly used. The correct use and maintenance of the tire mold is an effective way to improve the life of the tire mold, the main contents are:

1. The tire mold must be preheated evenly before use to improve the impact toughness of the mold material and prevent cracking during use. Preheating temperature is generally 150~250 ℃. The preheating method is usually to preheat the red-hot iron block in the mold. Attention should be paid to prevent local tempering on the surface of the mold chamber and reduce the hardness.
The measurement of preheating temperature is generally based on experience, such as spitting yellow spots on the tire mold to reach the preheating temperature. If available, surface thermometer can be used to measure.

2. mold cooling tire mold must be cooled at any time during use, and the working temperature should not exceed 400 ℃, otherwise local tempering will occur, resulting in collapse and cracking of the mold cavity.

3. die lubrication forging factory tire mold in the working process to be lubricated, in order to improve the life of the tire mold and forging surface smoothness. The lubricant can be used as a paste mixture of waste engine oil or waste engine oil and graphite, or saturated salt water. Salt water mainly plays a cooling role, but also has a certain lubricating effect, and the price is convenient, easy to use, health.

4. the correct operation method in order to prolong the service life of the tire mold, there must be a correct operation method in the production process. Before the forging blank is put into the die, the oxide scale should be cleaned to reduce the wear of the oxide scale on the surface of the die chamber. The operation should be quick to avoid the forging staying in the tire die for too long. Attention should be paid to the severity of the blow when processing small work with large equipment. When the forging temperature drops to black flash and rigid impact, hammering should be stopped immediately. The upper and lower anvil surfaces should be straight, and the die are sunken.
5., the tire die forging factory uses the tire die in a timely manner. If any bulge or collapse is found at the fillet protrusion, it shall be ground in a timely manner. When there is peeling or wear in some parts, surfacing welding can be used for repair welding, and slight grinding can be added after repair welding. When the wear in the die chamber is serious, appropriate measures can be taken to repair it. If cracks occur in the die chamber, hoop can be applied on the peripheral hot sleeve.

In terms of the quality of large forgings, due to the role of the mold during the forming process, the metal deformation is limited, the forged forgings are dense, the forging quality is relatively good, the surface quality is also good, the machining allowance is also small, and the material The utilization rate is greatly improved, the production efficiency is relatively high, and the forgings with more complex shapes can be forged, and large forgings can also be produced on small equipment, local molding can also be done.