Forming Requirements and Technological Conditions of Die Forgings
Die forgings mainly refer to the forgings with dies in the process of work. In the operation, the precision of forging with dies is relatively high and complex. The characteristics of die forgings should be based on free forging. Free forging basically does not have a die, but can only forge axles, rings and other extremely simple things. Die forging can forge many structural products, and can control the size tolerance of products and reduce the turning volume.
Die forging is a kind of forging, the influence of forging process on the direction of forging fiber, the position of mechanical properties test rod, the position of imprint and steel number, etc. Qualified forgings must also meet the following requirements: forgings forged in accordance with the forging process regulations should meet the requirements of all sizes on the die forging drawing, and at the same time, they must meet the requirements of the technical conditions specified in the die forging drawing, such as heat treatment hardness, displacement, rough edge size, bending degree and wall thickness difference. Surface defects, removal of oxide scales and mechanical performance requirements.
Three Special Considerations of Die Forging
(1) Forging press has an ejector rod device, which can stand to forge forgings with long rods (i.e. the axis of the rod is consistent with the direction of slider movement), so as to reduce the perimeter of the forgings on the split die surface and the consumption of the metal on the rough edge.
(2) The average dimension of the forgings forged on the forging press is 30-50% smaller than that on the hammer. The specific figures can be determined by referring to relevant manuals.
(3) If the forging is removed from the die groove by hand pliers, the die forging inclination is as determined as that of the hammer forging. When the forging is ejected by the ejector rod, the die forging inclination can be significantly reduced, but it can not be completely eliminated, otherwise the ejector rod will be overloaded.
The die used in die forging is called forging die. From the beginning of metal deformation to the end of forming, the corresponding chamber of the forging die is used. The forging die is divided into upper and lower forging dies, which are installed on the hammer head and anvil seat respectively. With the help of swallow tail and key groove, the forging die can be prevented from pulling out, loosening and lateral movement. The forging die is fastened in the swallow tail groove of the hammer head and the swallow tail groove of the anvil seat with key blocks and wedges to prevent the longitudinal movement of the forging die before and after. The deviation direction of the hammer wedge for upper and lower dies is different, and the small head of the key block is located in the key groove of the swallow tail of the forging die, and the big head is located in the key groove of the swallow tail groove of the hammer head or the die base.