NEWS

# Heat Treatment Process for H13 Mold Steel: Quenching, Tempering & Cryogenic Treatment H13 heat treatment is the core process to achieve target hardness, toug

  • Browse number: ...
  • Release time: 2026-09-29

Heat Treatment Process for H13 Mold Steel: Quenching, Tempering & Cryogenic Treatment

H13 heat treatment is the core process to achieve target hardness, toughness and thermal fatigue resistance. Improper heat treatment causes inconsistent hardness, distortion and early mold failure. This article describes H13 standard heat treatment curve and quality inspection standards.

Preheating: two-stage preheating at 650℃ and 850℃ to reduce thermal gradient inside mold blank, avoid quenching distortion for large mold blocks.

Quenching: austenitizing at 1020–1040℃, hold time 20–30 min per 100 mm thickness. Gas quenching to 150–200℃, cooling rate controlled to prevent thermal stress cracking.

Double tempering: first temper at 560–580℃, hold 2 hours; second temper at 570–590℃. Final hardness target HRC44–49. Single temper cannot fully relieve quenching stress.

Cryogenic treatment after quenching: cool down to -180 ~ -190℃, hold for 2–4 hours. Convert retained austenite into martensite, reduce residual stress and stabilize mold dimension.

Hardness inspection: 5–8 measuring points distributed on cavity surface, hardness deviation within ±1.5 HRC.

Distortion inspection after heat treatment: mold block deformation ≤0.04 mm per 500 mm length. Excessive distortion requires correction and re-machining.

Heat treatment defects: overheating leads to grain coarsening and low toughness; insufficient austenitizing results in low hardness and poor wear resistance.

Weld repaired local region needs local stress relief tempering at 550℃, to match substrate hardness.

Heat treatment batch traceability: record furnace temperature curve, hardness log and distortion measurement report for every mold block.

FAQ

Q1: What is the austenitizing temperature range for H13 quenching? A1: H13 quenching austenitizing temperature is 1020–1040℃. Q2: Why adopt double tempering for H13 mold steel? A2: Double temper fully relieves quenching residual stress and stabilizes final hardness. Q3: What is the function of cryogenic treatment after quenching? A3: Transform retained austenite, reduce residual stress and improve dimensional stability.

url: https://zj-xinfeng.com/news/1085.html