Alloy steels
Alloy steels are carbon steels with intentional additions of chromium, molybdenum, nickel, vanadium or aluminum to gain hardenability, hot strength or wear resistance.
Alloy steels: alloys supplied by Dustre
Forms: Bar, Pipe, Forging and flange, Casting, Plate, Fitting. Click an alloy to see standards by form, composition, properties and equivalents.
| Material | UNS | W.Nr. / EN | Forms |
|---|---|---|---|
| 300M steel (modified 4340)Alloy steel · Ultra-high-strength low-alloy steel: 4340 with silicon and vanadium | K44220 | Sem equivalente EN direto | Bar, Pipe, Forging and flange, Casting |
| SAE 4140Alloy steel · Chromium-molybdenum low-alloy steel for quenching and tempering | G41400 | 42CrMo4 | Bar, Plate, Pipe, Forging and flange |
| SAE 4340Alloy steel · High-hardenability nickel-chromium-molybdenum low-alloy steel | G43400 | ≈ 34CrNiMo6 | Bar, Plate, Pipe, Forging and flange |
| 8550 steel – 34CrAlNi7-10 (W.Nr. 1.8550)Alloy steel · Cr-Al-Ni-Mo nitriding steel | Sem UNS | 1.8550 | Bar, Forging and flange |
| ASTM A182 F1Alloy steel · Forged carbon-molybdenum (C-½Mo) steel for elevated temperature | K12822 | ≈ 16Mo3 | Plate, Pipe, Forging and flange, Fitting, Casting |
| ASTM A182 F5Alloy steel · Forged 5Cr-½Mo steel for high temperature and sulfidizing media | K41545 | X16CrMo5-1 | Bar, Plate, Pipe, Forging and flange, Fitting, Casting |
| ASTM A182 F9Alloy steel · Forged 9Cr-1Mo steel for high temperature and sulfidizing media | K90941 | X11CrMo9-1 | Plate, Pipe, Forging and flange, Fitting, Casting |
| ASTM A182 F11 Class 2Alloy steel · Forged 1¼Cr-½Mo steel for steam and elevated temperature | K11572 | ≈ 13CrMo4-5 | Plate, Pipe, Forging and flange, Fitting, Casting |
| ASTM A182 F22 / P22 (2¼Cr-1Mo)Cr-Mo alloy steel · All standards by product form | K21590 | 1.7380 10CrMo9-10 | Bar, Plate, Pipe, Forging and flange, Fitting, Casting |
| ASTM A182 F91 Type 1Alloy steel · Modified 9Cr-1Mo-V-Nb ("P91") steel for creep | K90901 | X10CrMoVNb9-1 | Plate, Pipe, Forging and flange, Fitting, Casting |
| Maraging 250Alloy steel · Age-hardenable 18Ni(250) maraging steel | K92890 | 1.6359 | Bar, Plate, Forging and flange |
| SAE 9315 – AMS 6263Alloy steel · High-hardenability Ni-Cr-Mo carburizing steel | G93150 | ≈ 15NiCr13 | Bar, Pipe, Forging and flange |
Did not find the alloy? See all materials or ask the technical team.
Which alloy resists each environment
Indicative summary from the corrosive media calculator, under typical conditions. For your medium, concentration and temperature, use the calculator.
| Material | Fresh water (200 ppm Cl⁻, 25 °C) | Seawater (20,000 ppm Cl⁻, 25 °C) | Sulfuric acid 20 %, 40 °C | Air at 800 °C |
|---|---|---|---|---|
| ASTM A182 F5 | — | — | — | not recommended |
| ASTM A182 F9 | — | — | — | not recommended |
| ASTM A182 F11 Class 2 | — | — | — | not recommended |
| ASTM A182 F22 / P22 (2¼Cr-1Mo) | — | — | — | not recommended |
| ASTM A182 F91 Type 1 | — | — | — | not recommended |
About alloy steels
Two uses dominate. Mechanical construction: 4140 and 4340 (Cr-Mo and Cr-Ni-Mo) for shafts, gears and pins, quenched and tempered; 8620 and 9315 for carburizing; 8550 (34CrAlNi7-10) for nitriding. High temperature and pressure: the Cr-Mo grades F11 (1¼Cr), F22 (2¼Cr), F5, F9 and F91 (9Cr-1Mo-V) for refinery flanges, fittings and vessels, resistant to creep and hydrogen attack.
Each element plays a role: chromium and molybdenum increase hardenability and hot strength; nickel gives toughness; vanadium refines the grain and holds creep strength; aluminum allows nitriding.
See also
Frequently asked questions
4140 or 4340?
4340 contains nickel and through-hardens in larger sections with more toughness; 4140 serves shafts and pins up to about 100 mm at lower cost.
What is F22 used for?
Flanges, fittings and forgings for refineries and boilers between 400 and 550 °C, where carbon steel loses strength and suffers hydrogen attack.