Everyone knows that stainless steel screws now require molds for stainless steel screws during the cold heading process. In the process of producing stainless steel fasteners, the mold is subjected to impact load. In order to reduce the damage in the form of breakage or chipping during use, the mold steel is required to have certain toughness.
The chemical composition, grain size, purity, carbide, inclusions, etc. of the die steel, the heat treatment system of the die steel and the metallographic structure obtained after the heat treatment are all on the steel. The resilience has a big impact. In particular, the purity of the steel and the deformation of the hot work have a more pronounced effect on the lateral toughness. The toughness, strength and wear resistance of steel are often contradictory. Therefore, the chemical composition of steel should be reasonably selected and reasonable refining, hot working and heat treatment processes should be adopted to achieve the best fit of the wear resistance, strength and toughness of the mold material.
Impact toughness is the total energy absorbed by a sample during the entire impact process during a single impact. However, many tools are fatigue fractured under different working conditions. Therefore, the conventional impact toughness cannot fully reflect the fracture properties of the die steel. Test techniques such as small energy multiple impact fracture work or multiple fracture life and fatigue life are being employed.