Cemented carbide wire drawing die—the form of failure of cemented carbide die

       The failure modes mainly include wear, fracture, local chipping, corrosion, fatigue, and voids. During the working process, the mold may have multiple damage forms at the same time, and various damages can penetrate each other, promote each other, and develop separately. When a certain damage develops and causes the mold to lose its normal function, it will cause the failure of the mold.

(1) Fracture failure.

       From the perspective of the southward deformation of the mold fracture and the shape of the fracture, the fracture can be divided into regular fracture and ductile fracture. There are many reasons for breakage and cracking. In addition to improper mold installation and operation, it is also related to mechanical design. Countries such as materials and heat treatment processes have close ties.

(2) Wear failure.

       Due to the relative movement of the mold in the working process, it cannot be protected from wear, so wear resistance is one of the basic properties of mold steel. The wear of cold work die is mainly occlusal wear and abrasive wear, and the wear of hot die is mainly heat wear.

(3) Fatigue failure.

       The load that the cold work mold bears is a certain amount of energy. Multi-impact load cyclic field loading. Stress fatigue failure is easy to occur: the thermal stress caused by repeated heating and cooling for a long time in a hot working die is prone to thermal fatigue failure. Especially for die-casting molds, thermal fatigue failure is about -70% total failure in about 60 years

(4) The cross shape fails.

       In cold extrusion, cold punching, cold punching and other processes, the punch is discharged and dropped due to insufficient bending strength due to compression. Failure such as bending. The hottest die hot forging die, especially the hottest lower die, due to the thermal effect of the hot blank, makes the cavity surface prone to void failure, such as softening, collapse, etc.

(5) Corrosion failure.

       The corrosion failure of metal die-casting molds mainly occurs in hot work molds and plastic molds, and the molds are prone to erosion. The use of plastic molds containing F and C plastics is prone to media corrosion failure.