Introduction to selection of cold deformation moulds
With the development of machining industry, there are more and more parts made by cold moulding in production.Sheet metal stamping (such as drawing, blanking, cutting edge, punching, etc.);Material rolling (cold rolling, roller forming, etc.).Although there are a wide range of cold deformation molds with different working conditions and different performance requirements, the basic working conditions are similar: namely, the metal is deformed in the cold state, and it bears relatively large shear force, pressure, bending force, impact force and friction force when working.Therefore, this kind of die steel shall have the following basic properties:
1) high hardness and high strength to ensure that it is not easy to generate micro plastic deformation or failure when bearing high stress.
2) high wear resistance, which can guarantee the dimensional accuracy of the mold under high wear conditions, is more important for the stretching mold and the cold stamping die.
3) sufficient toughness, so that under impact load and dynamic load, it is not easy to spalling or cracking of working toughness.
4) the heat treatment deformation is relatively small, because most of the molds have complex cavity and accurate precision, the deformation of the heat treatment is difficult to be eliminated by grinding. In addition, some cold deformation molds should have sufficient heat resistance.
How to choose the material and proper heat treatment of the cold deformation mold reasonably to improve the service life of the mold is the most concerned problem in production. The normal failure of the cold deformation mold should be wear, micro plastic deformation and fatigue failure.But in the actual production, in addition to wear and tear failure, and fracture, cracking, such as early failure, common.It is well known that the life of the cold deformation mold is a comprehensive factor.The rationality of the choice of raw material, the quality of metallurgy inside the raw material, the rationality of the design and manufacturing process, the conditions of use and the technical level of the operator, etc.