AMS 5599 Material: Properties, Equivalent, Chemical Composition

AMS 5599 defines the sheet, strip and plate form of Alloy 625 (UNS N06625) — a nickel-chromium-molybdenum-niobium superalloy prized for its corrosion resistance and high temperature strength. For procurement and design decisions, AMS 5599 material behaves consistently with commercial Inconel® 625 (UNS N06625): expect excellent resistance to chloride pitting and crevice corrosion, high tensile strength across a wide temperature range, and good weldability without age hardening. For buyers seeking mill-certified stock and fast shipping from China, MWalloys supplies AMS 5599 material at factory prices with prompt inventory dispatch.

What is AMS 5599 Material?

AMS 5599 is the SAE/AMS specification for corrosion- and heat-resistant nickel alloy sheet, strip and plate (nominally up to 1.000 in / 25.4 mm thick) produced to the Alloy 625 chemistry and condition for annealed / solution treated material. The spec is commonly issued as AMS 5599 with revision letters (e.g., AMS 5599H / AMS 5599J) and is the aerospace/aerospace-grade sheet/plate specification used by industry to ensure consistent chemistry, mechanical properties and traceability for UNS N06625 material.

Chemical composition & physical properties

Below is a practical composition and key physical numbers you can rely on for design and procurement. Actual certified material will show manufacturer test reports; use this as the engineering baseline.

Typical composition (nominal / weight %) — Alloy 625 / AMS 5599

(AMS 5599 gives the exact composition limits and testing requirements — consult the spec for procurement certificates.)

Physical properties (typical engineering values)

• Density: ≈ 8.44 g/cm³ (≈ 0.305 lb/in³).

• Melting range: broad solidus-liquidus window typical for nickel-based alloys (consult Special Metals data for precise values).

• Corrosion behavior: excellent general corrosion resistance in oxidizing and many reducing environments; strong resistance to pitting and crevice corrosion due to Cr + Mo; niobium stabilizes against sensitization.

Mechanical properties and hardness

AMS 5599 defines required mechanical testing; the values below reflect typical mill-certified annealed material in sheet/plate form. For critical designs, always use certs from the specific heat lot.

Typical mechanical values (annealed / solution treated condition):

• Yield strength (0.2% offset): ≈ 200 – 310 MPa (varies with thickness and temper).

• Tensile strength (ultimate): ≈ 550 – 900 MPa depending on temp and form.

• Elongation (in 2 in / 50 mm): typically ≥ 30% in annealed sheet.

• Hardness (HRC / HRB / HV): typical annealed hardness around HRB 80–95 (approx. ~<25 HRC), but hardness depends on cold work and product form. Use Rockwell or Vickers values from mill reports for exact numbers.

Temperature behavior: Alloy 625 retains good strength up to several hundred degrees Celsius and is used in elevated temperature applications up to about 980°C for short exposures; creep performance and specific elevated-temperature properties must be taken from product data and AMS/ASME rules when designing for long dwell times at high T.

Specification snapshot — what procurement teams need to know

Below are key procurement checkpoints extracted from AMS 5599 (summary, not a substitute for the actual standard).

AMS 5599 — succinct procurement checklist

• Form covered: sheet, strip and plate up to 1.000 in (25.4 mm) nominal.

• Condition: annealed / solution heat treated; acceptance testing includes chemical, tensile, hardness and intergranular corrosion when specified.

• Mill report (MTR) / Certification: must show heat number, chemical analysis, mechanical test results and any nondestructive / special tests required by the purchase order.

• Traceability: full heat/lot traceability back to melting required for aerospace or safety-critical parts.

Specification table (quick view)

Equivalents and cross-references

When specifying AMS 5599 material or sourcing from stockists, it's helpful to know the commonly accepted equivalents:

• UNS number: N06625 (widely used identifier).

• Trade names / producer names: Inconel® 625 (Special Metals), Haynes® 625 (similar chemistry in some variants), Alloy 625 (generic).

• Commonly referenced standards: ASTM B443 (sheet/strip), ASTM B446 (bar/rod), AMS 5869 (plate) — note that AMS 5599 is the aerospace sheet/plate spec; always confirm the exact spec required by the buyer.

Equivalency note: “Equivalent” in specification language usually means the chemistry and testing match the requirement. Many suppliers will list AMS 5599, ASTM and UNS cross-references; nevertheless, procurement for aerospace or safety parts must call out the exact AMS number required on the PO.

Fabrication, welding and heat-treatment guidance

Alloy 625 is valued because it attains high strength without precipitation hardening; this affects fabrication:

• Welding: Alloy 625 welds readily by common fusion and solid-state processes. Filler of matching composition is normally used to retain corrosion resistance and high-temperature strength in the weld. Post-weld heat treatment is not required for strength, but recommended when joint properties or stress relief are necessary — consult welding procedure specifications and the AMS standard.

• Forming: good ductility in the annealed condition; processes like bending and roll forming are routine for sheet and strip. Cold work will raise strength but may reduce corrosion resistance in some environments.

• Heat treatment: AMS 5599 calls for solution anneal and quench conditions appropriate to sheet/plate form. Alloy 625 is not age-hardening in the same way as precipitation-hardenable superalloys; its high strength comes from solid-solution strengthening (Mo + Nb).

Designers should ask suppliers for WPS/PQR and post-weld mechanical tests if welded assemblies will see elevated temperatures or corrosive media.

Typical applications and sectors

Alloy 625 (AMS 5599 sheet/plate) is used where corrosion resistance, fabrication flexibility and stability at temperature are required. Representative sectors:

• Aerospace: exhaust systems, heat shields, high-temp ductwork and chemical transport items where AMS specs are mandatory.

• Oil & gas / chemical processing: piping cladding, heat exchangers, valves, and components exposed to chloride or sour environments.

• Marine: seawater components, seafloor connectors and fittings due to resistance to pitting and crevice corrosion.

• Power & nuclear: components exposed to high temperature and corrosive service.

• Additive & specialty manufacturing: powders and wire in 3D printing or overlay applications (certified powder sources must be used).

Purchasing considerations & MWalloys supply offer

If you are sourcing AMS 5599 material, the following checklist will reduce risk:

• Confirm the exact AMS revision required on the PO (AMS 5599 has revisions; the lettered revision may matter for acceptance criteria).

• Specify form, temper and thickness (AMS 5599 covers up to 1.000 in).

• Demand mill test reports (MTRs) showing full chemical and mechanical results, and include inspection hold points if required.

• Ask for traceability to the melting heat number for safety-critical applications.

• Consider supply chain: Alloy 625 contains high nickel and molybdenum content and pricing/availability follow the nickel market; long lead times can occur during tight supply.

MWalloys offering: MWalloys supplies AMS 5599 / Alloy 625 sheet, strip and plate from our China stock. We provide:

• 100% factory price (direct mill relationships — lower landed cost for bulk buyers).

• Fast dispatch from stock for common sizes and thicknesses (standard sheets & cut-to-size).

• Full documentation: MTRs, heat numbers and inspection reports per buyer requirements.
  If you want immediate stock availability and a mill-certified quotation, contact MWalloys with material size, thickness and required certification level.

2025 global price comparison (practical ranges & market drivers)

Metal prices vary by product form, thickness, certificate level and order quantity. Below is a snapshot of typical market ranges for 2025 (presented as ranges to reflect form and regional spread). These are industry observed ranges synthesized from market reports and distributor price guides — use them for budgeting, not as firm offers.

Notes before the table:

• Prices fluctuate with nickel commodity markets (LME), producer surcharges and local premiums.

• “Sheet/plate” represents mill products (not fabricated or machined parts).

• Always request a current firm quote; the table is for comparative planning only.

2025 price ranges (approximate, USD)

Market drivers (short list):

• Nickel LME price swings and Indonesian NPI/Refining capacity impact raw material cost.

• Demand from oil & gas, power and aerospace can tighten supply for certified mill products.

• Order size, certification level (e.g., aerospace AMS certification), and required testing add to final cost.

FAQs

1. Is AMS 5599 the same as Inconel 625?
   AMS 5599 is the AMS specification for sheet/strip/plate produced to the Alloy 625 chemistry (UNS N06625). Inconel® 625 is a trade name for similar chemistry; specify AMS 5599 on the purchase order when you need that particular specification.

2. What is the UNS number for AMS 5599 material?
   UNS N06625 is the common identifier for Alloy/Inconel 625 chemistry.

3. What thicknesses does AMS 5599 cover?
   The spec covers sheet, strip and plate up to 1.000 in (25.4 mm) nominal thickness; for thicker plate verify alternative AMS or ASTM specs.

4. Does Alloy 625 need age-hardening?
   No — Alloy 625 attains its strength by solid-solution strengthening (Mo + Nb); it does not rely on age hardening like some other superalloys.

5. Can AMS 5599 material be welded without loss of corrosion resistance?
   Yes — when welded with matching filler and proper procedure, welds can retain resistance. For critical applications request welding procedures and test records.

6. Typical density and hardness values?
   Density ≈ 8.44 g/cm³. Annealed hardness is moderate (typically under ~25 HRC); measure hardness on your supplied MTR for exact numbers.

7. What industries most commonly demand AMS 5599?
   Aerospace, chemical processing, oil & gas, marine and power/nuclear sectors.

8. How volatile is pricing in 2025?
   Prices track nickel markets; 2025 saw significant regional variability and occasional price corrections. Expect quotes to reflect LME and surcharge adjustments. Always get a current quote.

9. Are there close substitutes to Alloy 625?
   Hastelloy C276 and some other nickel-based alloys offer alternative corrosion resistance profiles, but each alloy has different strengths; substitution requires engineering review.

10. What documentation should I require from suppliers?
    Mill Test Report (MTR), heat/lot number, chemical and mechanical test results, and any special nondestructive or traceability reports demanded by the purchase order or governing standard.

Practical notes for engineers and purchasers

• Always call out the AMS revision letter and required testing (e.g., intergranular corrosion, pitting testing) on the PO.

• For welded assemblies that will see high stress at temperature, request PQR/WPS from your fabricator and check for post-weld testing.

• If cost is a driver, compare sourcing regions: China often has lower mill prices for bulk but check lead time and certification. MWalloys can provide mill direct factory pricing with fast dispatch from stock for common specs.

Closing summary

AMS 5599 is the dependable aerospace/industrial sheet/plate specification for Alloy 625 (UNS N06625). The material’s combination of nickel, chromium, molybdenum and niobium gives it balanced high-temperature strength and top-tier corrosion resistance that many industries rely on. For buyers, the technical checks are straightforward: confirm the AMS revision, request full MTRs, and be clear about form/thickness and any special tests. For supply, MWalloys offers certified AMS 5599 plate and sheet at factory pricing with fast inventory shipment from China — contact us with sizes and certificates required to receive a formal quotation.

Authoritative references

• • SAE AMS 5599J — Aerospace Material Specification (full text / revision J PDF)
  • Special Metals — INCONEL® alloy 625 Technical Bulletin (composition, properties, guidance)