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The forging method for large piston rods is usually free forging, and there are also methods to reduce the machining amount of the piston rod head by using the piston head die forging and then welding with the piston rod. This process uses a combination of free forging and swaging to process the piston rod, which not only forms the head shape of the piston rod, but also achieves the integration of the head and rod of the piston rod. At the same time, this process can achieve mold production of several different specifications of products.
The free forging process can meet the actual production needs when the batch size is small, but for batch production, its shortcomings are exposed.
Free forging processing technology: heating, forging (free forging hammer 2t), normalizing, rough machining, heat treatment, and precision machining. The labor intensity of machining is high, and it is very difficult to manually process the complex shape of the piston rod head.