When the mold parts have these defects, qualified faste […]
When the mold parts have these defects, qualified fastener products cannot be formed, which will inevitably affect the production plan of the enterprise.Precaution:In order to prevent the early failure of the mold and effectively extend the service life of the mold, the corresponding preventive measures are mainly taken from the following aspects.First, the mold material:Because cold work dies have a large unit extrusion force, high-performance die materials with high strength, good toughness, and good wear resistance should be selected; because the working conditions of the male die are more susceptible to eccentric forces than the female die, The abrasion resistance of the mold material should be selected to be higher than that of the concave mold material.
Second, heat treatment:Mold heat treatment includes: timely tempering after cold forging the blank of the mold to refine the grains, tempering after roughing to eliminate stress, and low-temperature tempering after electric spark and wire cutting. Experience has shown that molds with a diameter of ≤80mm should be directly machined with bar material without further forging, because improper forging may cause defects such as overburning, coarse grains and segregation.
The quenching cooling speed is too fast and the swim temperature is too low, and the mold is prone to quench cracking. If the tempering temperature is too low and insufficient, the residual stress in the quenching process cannot be eliminated, the toughness of the mold is reduced, and early fracture is prone to occur.
Third, the mold design The structure of the cold work mold must have sufficient strength, stiffness, reliability and good orientation, but the irrational structure of the mold will directly affect the service life of the mold. The working part of the mold should be designed with a sufficiently large fillet radius to avoid stress concentration caused by the transition of sharp corners. The width of the ligament should be reasonably designed according to the flow of the metal to minimize the friction, generally between 1.5-3.5.