Inconel 718 Heat Treatment Guide - AMS 5662/5663, Aging Schedules & Machining Tips | Shanghai Hangbo Alloy Group
Date: 2026年8月15日 Categories: News Views: 231
By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 | Est. 2012
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360
Quick Answer: What Is the Correct Inconel 718 Heat Treatment?
Inconel 718 (UNS N07718) requires a two-step precipitation-hardening cycle to reach 1,275+ MPa tensile: Solution anneal at 927-1010C (AMS 5662) or 954-982C (AMS 5663), followed by aging at 718C for 8 hours + 621C for 8 hours total (double age). The critical secret: the 718C/8h step precipitates gamma-double-prime (γ″) while the 621C/8h step precipitates fine gamma-prime (γ′) — together delivering peak strength. This guide covers both AMS conditions, machining, and cost.
The Two AMS Heat Treatment Schedules
| Parameter | AMS 5662 (Annealed) | AMS 5663 (Solution) |
|---|---|---|
| Solution | 927-1010C / 1h / AC | 954-982C / 1h / AC |
| Age Step 1 | 718C / 8h / furnace cool | 718C / 8h / furnace cool |
| Age Step 2 | 621C / 8h / AC | 621C / 8h / AC |
| Tensile | >= 1275 MPa | >= 1275 MPa |
| Yield | >= 1034 MPa | >= 1034 MPa |
| Elongation | >= 12% | >= 12% |
Difference: AMS 5663 specifies a tighter, higher solution temperature for grain-size control in critical rotating components.
Why Double Aging? (The Metallurgy)
Inconel 718 hardens via TWO precipitates:
- γ″ (Ni₃Nb) — precipitated at 718C; the PRIMARY strengthener. Tetragonal, disc-shaped.
- γ′ (Ni₃(Al,Ti)) — precipitated at 621C; secondary fine strengthening.
Aging only at 718C leaves coarse γ″ without the fine γ′ that provides additional strength and creep resistance. The 621C step is the "fine-tune."
Machining Inconel 718: 7 Practical Tips
| Tip | Detail |
|---|---|
| 1. Carbide grades | Use ceramic or coated carbide (CBN for finishing) |
| 2. Speed | 25-40 m/min turning (1/3 of steel speed) |
| 3. Feed | Heavy feed preferred (work-hardens rapidly) |
| 4. Depth | >= 0.5 mm per pass — skip spring passes |
| 5. Coolant | Flooded, high-pressure — never dry |
| 6. Rigidity | Rigid setup mandatory (chatter = work-hardening) |
| 7. Tool angle | Positive rake; hone edges |
Condition & Product Matrix
| Condition | Tensile (MPa) | Typical Use |
|---|---|---|
| Annealed (AMS 5662) | 965-1170 | Machining blanks, non-critical |
| Solution + Aged (AMS 5663) | >= 1275 | Aerospace fasteners, discs |
| Direct-Aged (DA) | >= 1380 | Highest strength, limited ductility |
| Cold-Worked | 1400+ | Springs, retainers |
Price Guide (2026, EXW)
| Form | Price |
|---|---|
| Round Bar Ø50-150 mm | \$28-45/kg |
| Plate 10-50 mm | \$30-48/kg |
| Wire Ø2-5 mm | \$35-55/kg |
Inconel 718 vs A-286 (Quick Comparison)
| Property | 718 | A-286 |
|---|---|---|
| Tensile (aged) | >= 1275 MPa | >= 895 MPa |
| Max Temp | 650C | 700C |
| Cost | 2-3x A-286 | Baseline |
| Weldability | Good (strain-age risk) | Excellent |
Why Buy From Shanghai Hangbo?
- AMS 5662/5663 certified bars, plates, wire in stock.
- EN 10204 3.1 MTC with chemistry + mechanicals per heat.
- Triple aging performed in-house on request.
- SGS/TUV/BV inspection available.
- VIM+ESR melting traceability.
Contact & Complete Product Range
Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier
Email: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com
All Grades
Ni: NI200-N6 | Monel: 400-502, K-500, R-405 | Inconel: 600-740H, X-750, 725 | Incoloy: 800-27-7MO | Hastelloy: C-276-HYBRID-BC1, N | Super Austenitic: 904L-AL-6XN | Chromium-Rich: Alloy 33 | High-Strength Stainless: Nitronic 50/60, PH13-8Mo | Chlorination: Alloy 45 | Nimonic: 75-263 | Haynes: 25-HR-160 | RA: 330/333 | Precision: 1J22-4J45 | High-Strength: 18Ni250-AerMet100 | Heating: Cr20Ni80/60 | Specialty: Alloy 20-602CA
Product Forms: Bars(6-500mm) | Tubes(OD 6-610mm) | Plates(0.1-100mm) | Forgings | Welded Pipes | Fittings | Wire(0.05-10mm) | Strip(0.02-4.0mm)
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