Stainless Steel 418, also known as ‘Greek Ascoloy’ (UNS S41800) is engineered for use in high-stress components.
| % | C | Cr | W | Ni | P | S | Si | Mn | Fe |
|---|---|---|---|---|---|---|---|---|---|
| Min | 0.15 | 12.00 | 2.50 | 1.80 | - | - | - | - | Balance |
| Max | 0.20 | 14.00 | 3.50 | 2.20 | 0.04 | 0.03 | 0.50 | 0.50 | - |
Stainless Steel 418, also known as ‘Greek Ascoloy’ (UNS 41800) is a heat resisting martensitic chromium-tungsten-nickel stainless steel. Greek Ascoloy is engineered for use in high-stress components up to 649 ⁰C.
Typical heat treatment at 980⁰C -1010⁰C, followed by air or oil quenching (depending on material thickness) and 2-hour tempering twice at minimum 620⁰C gives Greek Ascoloy (Alloy 418) a superior creep strength and resistance to stress-corrosion cracking and tempering as compared to the general properties of 12% chromium stainless steels.
Filler metal, UNS S41880, has extra molybdenum (0.50 max.), copper (0.50 max.) and tin (0.05 max.) for effective welding process.
| Mechanical & Physical Properties | 21⁰C |
|---|---|
| Ultimate Tensile Strength /MPa | 965 |
| 0.2% Yield Strength /Mpa | 760 |
| Elongation % | 15 |
| Hardness (Brinell) | 302-352 (311 max. for annealed material) |
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