1.2738 Pre-hardened Plastic Mould Steel, hardness in as-delivered condition 280 to 325 HB. Good machinability, suitable for texturing, improved through hardening in comparison to 1.2311, good polishability.
Large plastic moulds with deep engravings and intensive impacts on the core. 1.2738 Pre-hardened Plastic Mold Steel is the logical development of 1.2311, a pre-hardened plastic mould steel for use in large moulds, which also have to display high core strength. The additional nickel content of 1 % increases through hardening. 1.2738 is a micro-alloyed, vacuum-degassed steel with the following excellent features: good machinability, outstanding polishability, good texturing properties.
Quality Standard: GB, ASTM
Similar Grade: 1.2738 P20+Ni 718
Size Range:Thickness1-3.5mm Width:800mm
Surface Condition: Bright
Delivery condition: Cold rolled only
Heat Treatment :
Annealing: Annealing temperature: 710 ~ 740 °C, holding time is decided by the thickness of the DIN 1.2738 die steel, one hour per 25mm. Colding in furnace after thermal insulation.
Destressing: Heating temperature: 600 °C (annealed condition), 550 °C (quenching and tempering state), holding time is decided by the thickness of the 1.2738 steel, one hour per 50mm. Colding infurnace after thermal insulation.
Quenching and tempering:
Preheating temperature 500 ~ 600 °C, quenching temperature 840 ~ 880 °C, holding 30min (the mold have to quenching in the protective gas to prevent oxidation and decarbonization). Oil cooling, cooling to 50 ~ 70 °C,immediately tempered. Tempering holding time is decided by the thickness of the 1.2738 steel mould, one hour per 25mm, at least 2h. Tempering temperature: 180 °C / 200 °C / 300 °C / 400 °C / 500 °C / 600 °C, the hardness: 52HRC / 51HRC / 48 HRC / 46HRC / 42HRC / 34HRC.
Mill′s test certificate:
EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.