Specialty Mold Steel
Schmolz + Bickenbach USA, Inc. showcased its specialty mold steel Corroplast FM, which was engineered to be significantly more machinable than other, established mold steels for plastics processing without suffering any reduction in corrosion resistance, the company states. Analysis of the new material reveals a well-balanced ratio of hardness, corrosion resistance and machinability.
A particular challenge was to homogenize the steel’s structure with the correct proportion of sulphur so as to optimize the machining properties of the specialty steel without impairing its performance characteristics. To meet this challenge, the melting process and subsequent secondary metallurgic treatment were both carefully adjusted. Further, the possibility of embrittling delta ferrite being formed was minimized through thermodynamic calculations, which resulted in optimal homogeneity of the structure.
This homogeneous structure ensures that Corroplast FM remains corrosion resistant even in an environment marked by heat, condensation and coolant. It also provides great stability for filigree components and molds with minimal cavity spacing. In addition to PET bottle manufacturers, other users who need complex, corrosion-resistant and easy-to-machine base and build-up plates, mold frames or plastic molds can benefit from this.
Corroplast FM mold steel can be purchased as rolled or forged plate 1,000mm wide and from 50mm to 400mm thick. Upon request, the company will provide six-side machining and chamfering.
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools, however, special attention needs to be paid during their heat treatment so as to achieve the best properties for a given application.
The use of venting material in appropriate areas can eliminate gas buildup, reduce injection pressure, lower cycle times, gloss levels and substantially reduce scrap and reject rates.
Problems associated with the texturing or polishability of a mold cavity can often be traced back to the mold steelmaking process.