Concept and advantages of die forging
Die forging refers to a forging method that uses a die to form a blank on a special die forging equipment to obtain a forging. The forgings produced by this method are accurate in size, small in machining allowance, complex in structure and high in productivity.
According to the different types of equipment used: die forging on hammer, die forging on crank press, die forging on flat forging machine and die forging on friction press, etc.
The most commonly used equipment for hammer die forging are steam-air die forging hammers, anvilless hammers, and high-speed hammers.
Forging die cavity: According to its different functions, it can be divided into two categories: die forging die cavity and billet die cavity.
(1) Pre-forging die cavity: The function of the pre-forging die cavity is to deform the blank to the shape and size close to the forging, so that when the final forging is performed, the metal can easily fill the die cavity to obtain the required size of the forging. For forgings with simple shapes or small batches, pre-forging die bores may not be provided. The fillet and slope of the pre-forging die cavity are much larger than that of the final forging die cavity, and there is no flash groove.
(2) Final forging die chamber: The function of the final forging die chamber is to deform the blank to the required shape and size of the forging, so its shape should be the same as that of the forging; The size of the forging die bore should be larger than the size of the forging by a shrinkage amount. The shrinkage of steel forgings is 1.5%. In addition, there are flash grooves around the die cavity to increase the resistance of the metal to flow out of the die cavity, to promote the metal to fill the die cavity, and to accommodate excess metal at the same time.