1.2738 Tool steel

Designation

Chemical composition:

Strength:

280 - 325 HB
(≈ 950 - 1100 N/mm²)

Thermal conductivity at 100 °C:

33.5 W/m K

Character:

low-sulphur tool steel, supplied in pre-toughened condition; due to its nickel content, it features uniform strength even with maximum plate dimensions

Application:

large cavity plates with deep cavities for items such as bumpers or dashboards, moulding frames

Treatment by

highly suitable:
Polishing, EDM, nitriding, etching

suitable:
Hard chrome

Heat treatment:

already pre-toughened; usually no heat treatment required

Soft annealing:
710 to 740 °C for about 2 to 5 hours; slow controlled cooling of 10 to 20 °C per hour to about 600 °C further cooling in air, max. 220 HB

Hardening:
840 to 870 °C
15 to 30 minutes keeping curing temperature
quenching in oil/hot bath/air 180 bis 220 °C
obtainable hardness: 53 HRC

Tempering:
slow heating to tempering temperature immediately after hardening; minimum time in furnace: 1 hour per 20 mm part thickness; tempering twice is recommended

Annealing graph:

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