418 (Greek Ascoloy)
Request a quote for 418 (Greek Ascoloy)418, better known as Greek Ascoloy, is a 12 percent chromium martensitic stainless with a tungsten addition that holds strength and creep resistance well above the ordinary 400 series at compressor operating temperatures.
It has a long service history in steam and gas turbine compressor blades, vanes and related hot section hardware.
Stocked as bar and forging billet, supplied annealed for machining or heat treated to the ordered condition.
Sizes and stock
- Sheet / plate: through .300" THK
- Round bar: through 8" DIA
- Forgings: available by request
Processing capabilities
- Shearing, waterjet, laser and saw cut blanks
- Centerless grinding, turning and polishing
- Penetrant dye and ultrasonic inspection, chemical assay and physical testing
Specifications
Material is released to the applicable specification with mill test reports and, on request, independent lab verification.
Why engineers specify 418 (Greek Ascoloy)
- Retains strength at elevated temperature
- Good corrosion and erosion resistance for turbine airfoils
- Established compressor blade material
- Hardenable by quench and temper
Nominal chemistry
Percent by weight, nominal composition per the governing specification. The mill test report for your heat is the controlling document.
Typical mechanical properties
| Condition | Tensile strength | Yield strength | Elongation | Hardness |
|---|---|---|---|---|
| Q&T | ~140 ksi | ~110 ksi | ~15% | ~30 HRC |
Typical published values for reference only, not for design. Properties vary with section size, product form and processing. Order to the specification and condition your drawing requires.
Typical applications
- Compressor blades and vanes
- Turbine hardware
- Steam path components
- High temperature fasteners
Fabrication notes
Machining
Austenitic grades work harden quickly, so use positive rake tooling, rigid setups, generous feed and flood coolant rather than light dwelling cuts. Martensitic and precipitation hardening grades machine most easily in the annealed or solution treated condition and are aged after rough machining.
Welding
Weldable by GTAW, GMAW, resistance and electron beam methods with matching or over alloyed filler. Stabilized and low carbon grades resist sensitization in the weld zone. Precipitation hardening grades are normally welded in the solution treated condition and aged afterward.
Forming
Sheet and strip form well in the annealed condition; cold worked tempers trade formability for strength. Allow for springback and, where specified, an intermediate anneal between draws.
418 (Greek Ascoloy) compared with similar grades
Jethete M152
Higher strength 12Cr martensitic grade used in discs, blades and shafts.
403 / 410
Lower alloy turbine blade grades with lower elevated temperature strength.
Designations and cross reference
- Material family
- Stainless Steel
- Series
- 400 Series
Working from an obsolete, foreign or superseded designation? Send it over and we will cross reference it to a current grade and specification.
Quality, testing and traceability
Supplied with mill test reports and heat traceability, with penetrant dye, ultrasonic, chemical assay, hardness, corrosion and mechanical testing available on request.
We are AS9100D and ISO 9001:2015 registered. If our stock does not already carry the inspection your specification requires, we can quote the material with that work performed. More on our quality system
Available forms
Custom sizes converted from billet, plus saw cut, waterjet and near-net blanks. See custom conversions
418 (Greek Ascoloy) frequently asked questions
What is 418 (Greek Ascoloy)?
418, better known as Greek Ascoloy, is a 12 percent chromium martensitic stainless with a tungsten addition that holds strength and creep resistance well above the ordinary 400 series at compressor operating temperatures.
What forms is 418 (Greek Ascoloy) available in?
We supply 418 (Greek Ascoloy) in bar, sheet, plate, forging. Custom sizes are converted from billet, and we can provide saw cut, waterjet or near net blanks so material arrives closer to your finished part.
What specifications can 418 (Greek Ascoloy) be supplied to?
Commonly ordered specifications include AMS 5508, AMS 5616, AMS 5817. Material is released to the specification and condition on your purchase order, with mill test reports supplied as standard.
What conditions can 418 (Greek Ascoloy) be ordered in?
We can supply Q&T. If our stock is not already in the condition you need, we can quote it with the heat treatment performed before shipment.
Can you cut 418 (Greek Ascoloy) to size?
Yes. Saw cutting, waterjet, laser and shearing are available, along with trepanning, gun drilling, lathe turning and CNC machining, so you can order blanks or rough machined pieces rather than full lengths.
Do you provide test reports and additional testing on 418 (Greek Ascoloy)?
Every order ships with mill test reports and heat traceability. If your print calls for ultrasonic inspection, penetrant dye, magnetic particle, chemical assay, micrography, hardness or mechanical testing and our stock does not already carry it, we can quote the material with that work performed.
Can 418 (Greek Ascoloy) be supplied to DFARS domestic melt requirements?
Tell us at quote stage if the order is DFARS or domestic melt restricted and we will confirm availability against that requirement before you commit.
What do you need to quote 418 (Greek Ascoloy)?
Grade, form, dimensions, quantity, specification and condition, plus any testing or certification requirements and the date you need it. Send a drawing if you have one. Quotes are typically ready within 24 hours.
How does 418 (Greek Ascoloy) compare with Jethete M152?
Higher strength 12Cr martensitic grade used in discs, blades and shafts.