Characteristics of NAK80 JIS Plastic Mold Steel
1. Excellent Polishing Performance
Mirror Polishing Capability: NAK80 contains elements such as nickel (Ni), aluminum (Al), and copper (Cu), which form fine and uniform precipitation-hardened phases. Its surface can be polished to a mirror-grade finish, making it suitable for transparent plastic products (e.g., optical lenses, light guide plates) and molds with high surface quality requirements (e.g., cosmetic packaging, automotive lighting).
EDM Surface Quality: After electrical discharge machining (EDM), the surface is smooth and fine, achieving a decorative effect similar to texture etching without the need for additional etching treatments. Moreover, the surface hardness does not increase, simplifying subsequent processing steps.
2. Good Machinability
Cutting Performance: NAK80 maintains excellent cutting properties in its pre-hardened state. High-speed steel tools (e.g., M2/SKH51) are recommended, with a cutting speed of ≤20 m/min to ensure precision. For drilling operations, the cutting speed should be reduced as the hole diameter increases; milling feed rates should follow a standard of 0.06 m per tooth to prevent excessive tool wear.
Forming Adaptability: It supports various forming methods, including cold drawing and hot rolling, making it suitable for manufacturing molds with complex structures.
3. Welding and Heat Treatment Properties
Wldability: The hardness of the heat-affected zone after welding is slightly lower than that of the base material. However, aging treatment at 500°C for 5 hours can restore the hardness, ensuring consistent performance between the welded area and the base material.
Heat Treatment Strengthening: Through a heat treatment process combining quenching (840–870°C) and tempering (200–500°C), the hardness can be increased to HRC 50–55. After gas nitrocarburizing treatment, the surface hardness can reach 750 HV, significantly enhancing wear resistance.
4. Corrosion Resistance and Toughness
Corrosion Resistance: Containing chromium (Cr), NAK80 exhibits moderate corrosion resistance, making it suitable for molds used in humid environments or those exposed to corrosive media.
Toughness: Despite its high hardness, NAK80 retains good toughness, reducing the risk of cracking or chipping during mold use and extending service life.
