Meaning
Martensitic chromium tool steels provide high polishability and resistance to corrosive degradation from volatile off-gasses during thermoplastic injection moulding. The DIN standard alloy designation 1.2083 stainless contains approximately thirteen percent chromium, providing protection against acidic outgassing generated by polyvinyl chloride or flame-retardant polymer compounds. Tooling engineers specify this material for optical lenses and medical housings where surface pitting would compromise clarity or cleanliness.
Protection stops when operating temperatures exceed tempering thresholds, which cause chromium carbide precipitation and reduce localized rust resistance.
Corrosion Resistance
Passivation layers formed by free chromium defend cavity surfaces from halogenated breakdown products. Moulding chlorinated polymers like rigid polyvinyl chloride releases hydrochloric acid vapor that attacks standard carbon steels within hours of cycle execution. Using 1.2083 stainless suppresses micro-pitting across thousands of production shots without requiring secondary plating treatments.
Condensation from chilled water channels also fails to oxidize cavity walls during extended down time.
Polishing Capability
Microstructural homogeneity dictates the ultimate specular reflection achievable on optical moulding surfaces. Steel produced via electroslag remelting minimizes non-metallic inclusions, enabling diamond compound polishing to A1 surface finishes. Specifying 1.2083 stainless in lens tooling prevents surface micro-voids from transferring defects onto clear polycarbonate components.
Hardening Response
Vacuum heat treatment converts the annealed structure into a tempered martensite matrix reaching fifty-two Rockwell C hardness. Higher core hardness resists indentation from high injection pressures and prevents deformation at parting lines. Over-tempering 1.2083 stainless lowers tensile strength and compromises dimensional stability across high-volume production runs.
