BS4659 BD3 is a high carbon high chromium, air hardening alloy tool steel with excellent resistance to wear and abrasion. D3 tool steel has good through hardening properties and dimensional stability combined with high resistance to tempering.
Chemical Analysis - D3 Tool Steel
| C. | Si. | Mn. | Cr. | |
| Min.% | 2.00 | 0.25 | 0.24 | 11.0 |
| Max.% | 2.35 | 0.45 | 0.45 | 13.0 |
Forging:
Heat slowly and uniformly to 700°C then more rapidly to 900/1050°C. After forging cool slowly, preferably in a furnace.
Annealing:
Anneal at 900°C and slow furnace cool. Hardness after annealing will be approx. 225 brinell.
Stress Relieving:
If machining operations have been heavy or if the tool has an unbalanced section, remove stresses before hardening by heating up to 700°C, equalise, then cool slowly.
Hardening:
Pre heat slowly to 750/800°C and thoroughly soak. Continue heating to the final hardening temperature of 950/1000°C and allow the component to be heated through. Cool in air or quench in oil.
Tempering:
Heat uniformly and thoroughly at the selected tempering temperature and hold for at least one hour per inch of total thickness. Double tempering should be carried out with intermediate cooling to room temperature