Greek Ascoloy 418 Stainless Bar - AMS 5616
Greek Ascoloy stainless is a high‑performance, martensitic stainless steel long valued for its exceptional strength, toughness, and resistance to high‑temperature oxidation. Originally developed for demanding aerospace and turbine applications, it combines elevated chromium content with carefully balanced alloying elements to deliver outstanding creep resistance and stability under extreme thermal cycling. Its ability to maintain mechanical integrity at temperatures where many stainless steels soften or scale makes Greek Ascoloy a trusted choice for turbine blades, fasteners, jet‑engine components, and other critical parts where reliability is non‑negotiable.
- Inventory & Specs
- Chemical Composition
- Physical Properties
- Mechanical Properties
- Datasheet
- Additional Info
- FAQs
Inventory Size Ranges for Greek Ascoloy
| Type | Thickness | AMS Standards | UNS | Get a Quote |
|---|---|---|---|---|
| Bar | 0.250" - 6.000" | AMS 5616 | UNS S41800 | Get a Quote |
Characteristics of Greek Ascoloy
Greek Ascoloy (Type 418 / AMS 5616) is a deep‑hardening chromium‑nickel‑tungsten martensitic stainless steel designed for high‑stress, high‑temperature service up to 1200 °F. This alloy is engineered for high temperature strength and retains strength and creep resistance at elevated temperatures. Greek Ascoloy outperforms standard 12% chromium martensitic stainless steels in hot service. Greek Ascoloy is extremely deep hardenable, ensuring uniform hardness through thick sections. making it ideal for large turbine components and high load parts. This alloy has superior creep strength, temper resistance, and strong stress corrosion cracking resistance. Additionally, this grade offers goof corrosion and oxidation resistance, making it suitable for stream, combustion gases, and industrial atmospheres.
Working with Greek Ascoloy
Greek Ascoloy® is machinable in all conditions, but performance varies depending on hardness. Best practices for machining include machining before final hardening, use carbide tooling for best tool life, and apply heavy coolant to control heat and avoid work hardening. Expect machinability similar to other deep hardening martensitic stainless steels such as 422 and 403. Greek Ascoloy can be formed, but only in the annealed or normalized condition. Guidelines for forming include performing bending, shaping, and cold-working before hardening, avoiding forming after heat treatment, and warm forming for tight bends to reduce springback. Heat treatment is central to unlocking Greek Ascoloy's high temperature peformance. A typical heat treat cycle includes austenitize at 1796–1850 °F (980–1010 °C), air or oil quench depending on section size, and Double temper at ≥1148 °F (620 °C). Heat treating achieves deep hardening through thick sections, high creep strength, strong resistance to tempering, and excellent high temperature stability. Greek Ascoloy is weldable but is best welded in the annealed condition. It is recommended to preheat and post weld heat to avoid cracking and after welding, re-tempter to restore mechanical properties.
Other industry standards we comply with:
- PWA LCS
- GE Aircraft Engine (GT193)
- GE S400
- DFARS Compliant
- RR SABRe
- Line marked > .500 inch diameter
- Predominantly produced by VIM-VAR melt method. Hot rolled, fully annealed, then centerless ground or rough turned.
Common Trade Names
Industry Applications for Greek Ascoloy
- Steam turbine buckets and blades
- Gas turbine compressor parts
- High temperature bolts
- Jet engine compressor blades and vanes
- Turbine diffuser components
- Aircraft landing gear
- Petrochemical components
Chemical Composition
| Element | Min | Max | |
|---|---|---|---|
| Fe | Iron | - | 81.00 |
| Cr | Chromium | - | 13.00 |
| W | Tungsten | - | 3.00 |
| Ni | Nickel | - | 2.0 |
| C | Carbon | - | 1.00 |
Physical Properties
| Property | Value |
|---|---|
| Density | 0.284 lb/in3 (7.86 g/cm3) |
The corrosion resistance of Greek Ascoloy 418 stainless bar is similar to Alloy 410 stainless bar. This grade resists oxidation up to 1400˚F (760˚C) and may be used in continuous service at 1100˚F (593˚C). A wide range of mechanical properties can be obtained by hardening and tempering this alloy.
Mechanical Properties
Hardness
Hardness of stock is typically 250 BHN. Supplied in the fully annealed condition. Hardening of this grade is accomplished by austenitizing at 1750-1800ºF (954-982°C) followed by air or oil quench to form martensite. Immediately following austenitizing, tempering should be carried out in the range of 1000-1250ºF (538-677°C) for two hours. The hot working range is 1700-2150ºF (927-1177°C). Large sections should be preheated at 1200-1400º (649-760°C) to prevent strain cracking.
Machinability
Rating: 55% OF B-1112.
Typical stock removal rate: 90 surface feet/minute with high speed tools, 150 surface feet/minute with carbide. Best machinability is in the fully annealed condition. Greek Ascoloy 418 stainless bar has a low work hardening rate and is not "gummy" like austenitic stainless steels during machining.
Datasheet
Additional Info
A Brief History of Greek Ascoloy
Greek Ascoloy® emerged as part of the evolution of 12% chromium martensitic stainless steels, which were widely used in early turbine and high‑temperature machinery. As turbine technology advanced, engineers needed a stainless alloy that could maintain strength at elevated temperatures up to 1200°F, resist creep, tempering, and stress corrosion cracking better than standard 12% Cr steels, and provide deep hardenability for large or high stressed components.
How Greek Ascoloy Was Developed
Greek Ascoloy® was engineered by modifying the traditional 12% chromium martensitic stainless family with nickel and tungsten additions. Key metallurgical features included chromium (12–14%) for oxidation and corrosion resistance, nickel (1.8–2.2%) to stabilize martensite and improve toughness, and tungsten (2.5–3.5%) to dramatically improve creep strength and high‑temperature stability.
Early Applications of Greek Ascoloy
The earliest and most common uses of Greek Ascoloy centered on turbomachinery, where high‑temperature strength and creep resistance were essential. Other applications included stream turbine buckets and blades, gas turbine compressor parts, high temperature bolts, and components exposed to prolonged stress and heat.
How Greek Ascoloy is Used Today
Greek Ascoloy remains relevant in modern high‑temperature engineering thanks to its combination of oxidation resistance, creep strength, and mechanical stability.
- Aerospace: Compressor parts, blades, structural hardware
- Power Generation: Steam turbine buckets, blades, bolts
- Fasteners: Industrial high temperature bolts and hardware exposed to heat and stress
Your Trusted Supplier for Greek Ascoloy
United Performance Metals offers Greek Ascoloy bar 0.250" - 6.000". This grade is used for jet engine compressor blades due to resistance to stress corrosion cracking. Also used for discs in lower temperature turbine stages and for turbine diffuser components.
Product FAQs
Greek Ascoloy maintains strength and creep resistance up to 1200 °F (649 °C). It outperforms standard 12% chromium stainless steels at elevated temperatures.
Yes, Greek Ascoloy is machinable in all conditions, however, machining is easier before final hardening and carbide tooling is recommended for hardened conditions.