1.2316 Plastic mold steel | 420Mo | 3Cr17Mo | SUS420J2

1.2316 Plastic mold steel | 420Mo |

3Cr17Mo | SUS420J2

1.2316 is a martensitic stainless chromium steel with uniform hardness in all dimensions, it is easy to machine, high surface finish and polishability. 1.2316 is commonly used for plastic moulds, and offers a higher corrosion resistance than 1.2083. It can be used with for the manufacturing of chemically aggressive materials like PVC and plastics containing abrasive fillers.

Chemical Composition

Annealing

810 - 830 °C (typically held for 1-2 hours per 25mm of section thickness to ensure uniform heating), followed by furnace cooling to below 500 °C before air cooling. Hardness after complete annealing treatment: Maximum 235 HB (Brinell Hardness), which ensures good machinability and dimensional stability for subsequent processing steps.

Stress relieving

Soak at 600 - 650°C for 1 - 2 hours per 25mm of section thickness to ensure uniform heat distribution, then furnace cool slowly to room temperature. This process effectively reduces internal stresses induced by machining, welding, or cold working, preventing dimensional distortion and cracking during subsequent processing.

Hardening

Heat uniformly to 1020 - 1040 °C (soaking time depends on section thickness, typically 20 - 30 minutes per 25mm to ensure complete austenitization). Quench immediately in oil maintained at 500 - 550 °C (the oil temperature helps control cooling rate to minimize thermal stress and distortion). Hardness after quenching reaches 48 - 52 HRC, which provides the high strength and wear resistance required for plastic mould applications, especially for parts needing precise dimensional stability.

Tempering

Applications

· Injection mould for plastics,

· die-casting moulds,

· moulding of corrosive material (PVC),

· extrusion tools