Step 4 of 10
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Forge die building: why this course exists
The eight decisions that set forge die life before the first hit, and why the build is a chain where the weakest link sets the floor.
Step 4 of 10Decision 4 — Heat-treat path
Austenitize temperature and soak, quench medium and rate, and a two- or three-stage temper define the substrate's metallurgical state. The certificate says 48 HRC. It does not say whether the quench cleared the carbide-precipitation nose on the TTT curve, which is where 3-4x life differences hide on H13 inside the same hardness window. Lesson 5 covers what to ask the heat treater for and what the cert leaves out.
Quick check
Two heat treaters return H13 forge dies to the same 48 HRC target. One ships a vacuum cycle trace showing the quench cleared the 540°C to 1010°C window in 4 minutes. The other ships only the final hardness. Why does the trace matter when the hardness numbers match?