P20 (2738)
Grade Introduction:
DIN 1.2738 steel is one kind of plastic mold steel, equivalent to AISI P20+Ni Tool Steel. While Nickel, chromium, and molybdenum are the alloying elements for hardness and toughness. 1.2738 tool steel is specially designed for the plastic mold industry, especially for big steel mold parts.
- DIN 1.2738 tool steel is usually supplied as pre-hardened/quenched and tempered 280 – 320 HB hardness condition.
- With good machinability, DIN 1.2738 steels are with better polishability compared to 1.2312 (AISI P20+S).
- Material 1.2738 can be through nitrogenation and flame hardening treatment in order to increase the hardness and wearability of the mold surface.
The steel 1.2738 is melted in an electrical furnace and refined with VOD or DH device.
Grade Application:
1.2738 mold steel materials are generally used for relatively low-temperature applications such as die-casting dies and injection molds, synthetic plastic molds dies, especially for large plastic molds highly stressed in the core, hydroforming tools, such as up to 400 mm in the construction of plastic molds. DIN 1.2738 is suitable for nitriding and chrome plating.
Equivalent grades:
Country | German | USA |
Standard | DIN EN ISO 4957 | ASTM/AISI |
Grades | 1.2738 | P20+Ni |
Chemical composition:
The following table shows the chemical composition of P-20+Ni steel:
DIN ISO 4957 | C | Mn | P | S | Si | Cr | W | Mo | Ni |
1.2738 | 0.35-0.45 | 1.30-1.60 | 0.03 | 0.03 | 0.20-0.40 | 1.80-2.10 | - | 0.15-0.25 | 0.90-1.20 |
ASTM/AISI | C | Mn | P | S | Si | Cr | W | T | Mo |
P20+Ni | 0.28-0.40 | 0.60-1.00 | 0.03 | 0.03 | 0.20-0.80 | 1.40-2.00 | 0.30 | 0.55 | 0.90-1.20 |
Hardness:
235
Heat treatment:
Heat Treatment of 2738 – Usually already pre-toughened, no heat treatment required, if there are no special requirements.
Hardening:
Harden from a temperature of 840-870°C followed by oil, then quenching in oil/hot bath/air 180~220 °C. Hardness after quenching is around 52 HRC.