How to Specify ADI: ASTM A897 vs EN 1564, Heat-Treat Guide

Table of contents

Scope & why it matters

• ADI (Austempered Ductile Iron) converts ductile iron into a tough, high-strength material via austenitize → quench above Ms → isothermal hold to form ausferrite.
• Two standards dominate buyer specifications:
• ASTM A897/A897M — six strength/ductility classes defined by minimum tensile (Rm), yield (Rp0.2), and elongation (A%).
• EN 1564 — five ADI grades (EN-GJS-800-10 … EN-GJS-1400-1). Minimums depend on related wall thickness t (≤30 / 30–60 / 60–100 mm).
• If your parts involve thin sections, sealing faces or impact loads, picking the right grade avoids over-spec (cost ↑) or under-spec (risk ↑).

Grade cross-map: ASTM A897 ⇆ EN 1564

A practical nearest-equivalent for engineering selection. EN limits vary with t; values below assume t ≤ 30 mm (≈1.18 in). Lock acceptance criteria in your PO/quality agreement.

Impact & microstructure notes

• Matrix must be ausferrite; small martensite/carbide islands may appear at top strengths.
• Target ≥80% nodularity to unlock toughness.
• Impact (unnotched Charpy) and hardness can be added by contract when function-critical.

Heat treatment notes (austempering window)

Values are typical; set exact test & DFT during PPAP. Units show µm / mil (1 mil = 25.4 µm).

• 1) Austenitize — typically 840–920 °C (1545–1690 °F); soak to uniform austenite.
  2) Quench to isothermal temperature (above Ms) — rapid transfer into ~250–400 °C (480–750 °F) salt/oil bath. Lower hold → higher strength/hardness, lower elongation. Avoid any pearlite during transfer.
  3) Isothermal hold → ausferrite — hold to completion, wash, then temper/stabilize as needed.

Chemistry nudges for deep sections:

• Use Ni/Cu/Mo judiciously to raise hardenability; avoid excessive Cu that slows carbon partitioning.
• Keep S/P/residuals tight to maintain nodularity and prevent carbides.

Section size & alloying (practical limits)

• EN 1564 ties properties to related wall thickness t; larger t allows lower minimums.
• For t > 30 mm (1.18 in), plan alloy assistance (Ni/Cu/Mo) and fast quench transfer to avoid pearlite.
• Gating/rising and transfer time are make-or-break for 50–100 mm (2–4 in) sections.

• → Green Sand Casting
• → Resin vs Green Sand

Inspection & documentation package

Request these with your ADI order/RFQ:

• Mechanical: Rm, Rp0.2, A%; hardness (HBW); impact if critical.
• Sampling: Define separate/attached/from-casting coupons; for EN, state t-band.
• Metallography: Nodularity %, graphite count, ausferrite verification; include micrographs.
• Dimensional: FAI/CMM plan tied to datums; add NDT/leak testing where applicable.
• Traceability: Heat/batch IDs and certs.

Internal resources to standardize deliverables:

• → PPAP Levels & Docs
• → Foundry Quality KPIs

Drawing & specification tips

• Primary standard + nearest alternative
• ASTM A897 Grade 1050-750-07 (or EN-GJS-1050-6, t ≤ 30 mm).
• Declare related wall thickness (EN) and coupon type.
• Hardness/impact only when function-critical; specify value/temperature.
• Tolerances & machining stock: pair the material spec with realistic casting capability:
• → ISO 8062 CT Grades
• → Open GD&T Guide
• Surface: ask for as-cast Ra only if it replaces machining; otherwise, set Ra on machined faces.
• Process window: for ≥1200 MPa grades, include an austempering temperature band (e.g., 300–330 °C) in the tech agreement.

Related articles on your site:

• Surface Finish (Ra) by Process
• Shell Molding for Thin-Wall
• Sand Inclusion & Burn-On Fixes

Applications & selection shortcuts

• 750-500-11 / EN-GJS-800-10 — high ductility & damping for housings/brackets.
• 900-650-09 → 1050-750-07 / EN-GJS-900-8 → 1050-6 — general structural parts, pump/compressor housings.
• 1200-850-04 / EN-GJS-1200-3 — gears, sheaves, wear tracks.
• 1400-1100-02 / EN-GJS-1400-1 — thin/highly loaded parts (watch notch sensitivity).
• 1600-1300-01 (ASTM only) — steel-replacement cases; strict section control and QA.

What YB Metal delivers

YB Metal Solution quotes with a corrosion plan attached:

• A coating selection matched to your environment (DFT numbers, cure, adhesion tests).
• Surface prep & blast profile setup, plus masking & hanging instructions.
• If required, material upgrade options (Cu/Ni DI or Ni-resist) with cost/lead-time impact.
• Pilot evidence pack: DFT logs, adhesion photos, salt-spray/cyclic results, and coated-part dimensional check.

Need a plan for your environment? Upload your drawing—we’ll return recommendations and a quote.