TGP-40 (DIN 1.2738 & DIN 1.2738HH) steel is one kind of plastic mold steel especially for big steel mold parts, it is equivalent to AISI P20+Ni tool steel.
Smelting method : EAF+LF+VD+ESR
Main Characteristics : If futures excellent hardening penetration, good workability, polishing and photoengraving properties, This steel is used for plastic moulds of medium and big size. It can be subject to a nitriding treatment to improve its wear resistance.
Major Applications : Injections and thermoplastic extrusion moulds, rubber moulds, moulds carrier frames, container.
Chemical Composition : (%)
Comparable Standards : (%)
|~40 CMND8||~P20 + Ni||~P20 + Ni|
Critical points :
Supply Conditions : Hardened and Tempered Normal HP 280-320 & 380-400
- Heat to 710-740℃, with hold at minimum rate for 3 hours.
- Slow furnace cooling to 600℃.
Thermal Heat Treatment :
- To be carried out after machining and before the final heat treatment
- Heating to 530-580℃ for 2 hours.
Stress relieving :
- Preheating to 500-550℃
- Austenitizing at 840-880℃
- Oil or thermal bath cooling at 200-230℃, then oil cooling according to the steel shape size
- Quenched hardness 52-54 HRC
- To be carred out after the hardening and when the steel is at 60-80℃, at 500-600℃ according to the required hardness and with permanance for atleast 2 Hr.
- Cooling in air