12th Tooling Conference & Exhibition - Tooling 2022

Steels for production of frames for plastic molds frequently need to be stainless, while at the same time require large amounts of machining. Machinability as a crucial property can be enhanced by the addition of sulfur, resulting in the formation of favorable sulfides, which in turn can deteriorate mechanical properties and resistance to corrosion. The detrimental effect on mechanical properties is caused i.a. by elongation of sulfides during rolling or forging. In a novel approach, a special wire treatment of the melt was performed, which resulted in improved, spherical morphology and chemical composition of the inclusions, yet leading to even enhanced machinability (tested i.a. by means of milling). Milling tests revealed an increased productivity compared to conventionally manufactured material, which means improved lifetime of milling inserts even at highest cutting speeds. At the same time, mechanical properties, in particular toughness, were slightly improved, while corrosion resistance was not severely affected.