Crucible Steel KAPSTAR® Mold Steel

Crucible Steel KAPSTAR® Mold Steel Product Information -:- For detailed product information, please contact sales. -: Crucible Steel KAPSTAR® Mold Steel Synonyms -:- For detailed product information, please contact sales. -:

Crucible Steel KAPSTAR® Mold Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: Crucible Steel KAPSTAR® Mold Steel** Crucible Steel KAPSTAR® is a premium, vacuum-degassed, corrosion-resistant martensitic stainless mold steel, specifically engineered to bridge the gap between standard mold steels (like P20) and high-alloy stainless steels. It is designed for applications requiring **exceptional corrosion resistance, excellent polishability, and good wear resistance** in demanding molding environments, particularly those involving **corrosive plastics, additives, or high-humidity conditions**. The name "KAPSTAR" reflects its capability as a star-performing material in corrosive ("KAP" from the German "Korrosion") environments. KAPSTAR® offers a significant performance upgrade over pre-hardened P20-type steels when corrosion is a primary concern, such as in molding PVC, flame-retardant materials, or materials that release acidic byproducts. It is typically supplied in a pre-hardened and tempered condition, providing immediate machinability without the need for subsequent heat treatment. Its balanced composition provides a reliable combination of hardness, toughness, and the stainless property, making it a versatile and durable choice for high-quality, long-life production molds. --- ## **1. Chemical Composition (Weight %)** The composition is a martensitic stainless steel with balanced chromium, nickel, and molybdenum for corrosion resistance and hardenability. | **Element** | **Chromium (Cr)** | **Nickel (Ni)** | **Molybdenum (Mo)** | **Carbon (C)** | **Manganese (Mn)** | **Silicon (Si)** | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content** | **13.50 - 15.00** | **0.80 - 1.20** | **0.80 - 1.20** | **0.20 - 0.30** | **≤ 1.00** | **≤ 0.80** | | **Role** | **Primary corrosion resistance element.** Forms a passive chromium oxide (Cr₂O₃) layer on the surface, providing excellent resistance to rust, tarnishing, and attack from many chemicals and plastics. | Austenite stabilizer; enhances toughness, ductility, and hardenability. Improves through-hardening characteristics. | Enhances hardenability, increases strength (especially yield strength), and significantly improves resistance to pitting and crevice corrosion. | Provides base strength and hardness. Kept at a moderate level to ensure good toughness and weldability while allowing for sufficient hardness. | Aids in deoxidation and contributes to hardenability. | Deoxidizer and solid solution strengthener. | *Note: Iron (Fe) constitutes the remainder. Sulfur and phosphorus are kept at very low levels to maximize purity and polishability.* --- ## **2. Physical & Mechanical Properties** *Typically supplied in a pre-hardened and tempered condition to a uniform hardness of 30-34 HRC.* * **Density:** ~7.75 g/cm³ (0.280 lb/in³) * **Modulus of Elasticity:** ~200 GPa (29.0 x 10⁶ psi) * **Thermal Conductivity:** Moderate. * **Supplied Hardness:** **30 - 34 HRC.** This pre-hardened state offers a good balance of machinability and wear resistance for immediate use. * **Corrosion Resistance:** **Excellent (for a mold steel).** Superior to P20 and many other alloy mold steels. Highly resistant to rust from cooling water, humid atmospheres, and corrosive plastic decomposition products (e.g., HCl from PVC). * **Polishability:** **Excellent.** Capable of achieving very high-grade, mirror-like surface finishes (e.g., SPI-A1), which is critical for optical parts, lenses, and high-gloss surfaces. The clean, homogeneous structure is key. * **Machinability:** **Good.** In its pre-hardened state, it machines well with appropriate tooling and parameters, though slightly more challenging than P20 due to its higher strength and work-hardening tendency. * **Toughness:** **Good.** Adequate impact resistance for most mold applications, including complex cores and slides. * **Wear Resistance:** **Good.** Better than P20 at equivalent hardness due to its finer microstructure and alloy content. Suitable for molding abrasive filled plastics, though for extreme cases, surface hardening may be applied. * **Dimensional Stability:** **Very Good.** Exhibits minimal distortion during machining and in service. --- ## **3. Processing & Heat Treatment** KAPSTAR® is designed for user-friendly processing in its supplied condition. * **As-Supplied Condition:** **Pre-hardened, tempered, and stress-relieved to 30-34 HRC. Ready for machining.** * **Machining:** Can be machined directly using techniques for 32 HRC material. Use sharp, positive-rake carbide tools. * **Finishing:** Excellent response to polishing, texturing (EDM, laser), and photo-etching. * **Welding:** Weldable with proper precautions (pre-heat, post-heat, matching electrodes). Commonly welded for mold repairs. * **Surface Hardening:** Can be nitrided (gas or plasma) to significantly increase surface hardness (up to 70+ HRC) for extreme wear resistance without affecting corrosion resistance. --- ## **4. Key Applications** KAPSTAR® is the ideal choice for molds operating in corrosive or high-hygiene environments. * **Molds for Corrosive Plastics:** PVC (polyvinyl chloride), flame-retardant (FR) plastics, polyurethane (PU) foam, and other halogenated or acidic material molds. * **Optical and High-Gloss Molds:** For lenses, light guides, reflectors, and consumer electronics parts requiring superior polishability and stain-free surfaces. * **Medical Device and Food Packaging Molds:** Where hygiene, corrosion resistance, and cleanability are paramount. * **Molds for Regrind/Recycled Materials:** Often contain contaminants that cause corrosion in standard steels. * **Large Molds Exposed to Humid Environments:** To prevent rusting during storage or operation. --- ## **5. International Standards & Cross-References** KAPSTAR® is a proprietary grade but aligns with the family of pre-hardened, corrosion-resistant martensitic stainless mold steels. * **AISI/SAE:** Similar to a modified **420** or **422** type stainless steel with optimized pre-hardened properties. Not a direct AISI standard. * **European (EN):** **1.2083** (X42Cr13) is a similar corrosion-resistant martensitic mold steel, though KAPSTAR's composition may include Ni and Mo for enhanced properties. * **Japanese (JIS):** **SUS420J2** (modified, pre-hardened) or **S-STAR** (Daido's proprietary equivalent) are close analogues. * **Common Industry Equivalents:** **Uddeholm STAVAX ESR, Böhler M300, Thyssenkrupp GS-083, Daido NAK 80 (similar in application but different composition).** * **Material Type:** Pre-hardened martensitic stainless mold steel. --- ## **6. Advantages & Limitations** **Advantages:** * **Superior Corrosion Resistance:** Eliminates rust problems, reduces maintenance, and ensures part quality. * **Outstanding Polishability:** Achieves the highest surface finishes required for aesthetic and optical parts. * **Good All-Round Mechanical Properties:** Balanced hardness, toughness, and wear resistance in a ready-to-use condition. * **Reduced Downtime:** Pre-hardened state eliminates heat treatment risks and reduces mold manufacturing lead time. * **Long Mold Life:** Resists degradation from both wear and corrosion, extending production run times. **Limitations:** * **Higher Cost:** More expensive than standard P20 or alloy mold steels. * **Machinability:** Slightly more difficult to machine than P20, requiring appropriate tooling and parameters. * **Not for Extreme High-Temperature Molding:** While good, its maximum continuous service temperature is lower than hot work steels. * **Thermal Conductivity:** Lower than some alloy steels, which can be a consideration for high-cycle molding. --- ## **7. Summary** **Crucible Steel KAPSTAR® is the definitive problem-solving mold steel for applications where corrosion is the enemy of quality, productivity, and tool life.** It transforms the challenge of molding aggressive materials from a maintenance headache into a reliable, high-performance process. By delivering stainless properties, exceptional polishability, and ready-to-machine convenience in one material, KAPSTAR® enables mold makers to produce durable, high-precision tools for the most demanding applications in the medical, optical, consumer electronics, and specialty plastics industries. It is not just an alternative to P20; it is a strategic upgrade that safeguards investment, ensures part quality, and maximizes uptime in corrosive molding environments. -:- For detailed product information, please contact sales. -: Crucible Steel KAPSTAR® Mold Steel Specification Dimensions Size： Diameter 20-1000 mm Length <7001 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Crucible Steel KAPSTAR® Mold Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Crucible Steel KAPSTAR® Mold Steel -:- For detailed product information, please contact sales. -: Chemical Identifiers Crucible Steel KAPSTAR® Mold Steel -:- For detailed product information, please contact sales. -:

Packing of Crucible Steel KAPSTAR® Mold Steel -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3472 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition