Stainless Steel 1.4422 +QT800
Heat-treated state
EN 1.4422
+QT800 = quenched and tempered, Rm 800–1000 MPa
Intermediate strength class often specified for shafts and flanges in medium-thickness sections.
Values for the +QT800 condition
Other 1.4422 tempers and conditions
1.4422 is listed in 7 conditions; see the grade overview at 1.4422.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for heavy machining or cold work before final quench-and-temper. | 600 | 800 | 20 | 24 HRC | 2.3 % IACS |
Quenched and tempered, Rm 760–960 MPa | Lower-strength, highest-toughness QT class for thick sections, welded pump casings and sour-service parts. | 640 | 850 | 19 | 26 HRC | — |
+QT800This page Quenched and tempered, Rm 800–1000 MPa | Intermediate strength class often specified for shafts and flanges in medium-thickness sections. | 700 | 900 | 18 | 29 HRC | 2.3 % IACS |
As-welded deposit | Reference condition for matching-consumable welds before post-weld tempering; a 600–650 °C PWHT restores toughness. | 700 | 900 | 15 | 33 HRC | 2.3 % IACS |
+QT900Default Quenched and tempered, Rm 900–1100 MPa | Standard stocked condition: best strength/toughness balance for pump and compressor shafts, impellers and marine hardware. | 780 | 980 | 17 | 31 HRC | — |
+C | Pick for precision shafting where h9/h11 tolerance and a ground surface are needed straight from stock. | 820 | 1,000 | 15 | 32 HRC | 2.3 % IACS |
Quenched and low-temperature tempered, Rm ≥1000 MPa | Highest strength class for small-diameter shafts and fasteners where toughness and sour-service margin can be traded away. | 880 | 1,070 | 15 | 35 HRC | 2.3 % IACS |
What is 1.4422 +QT800?
1.4422 +QT800 is 1.4422 heat treated to +QT800 — intermediate strength class often specified for shafts and flanges in medium-thickness sections. 1.4422 +QT800 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi). 1.4422 +QT800 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F). +QT900 is the default condition FabDigit quotes; +QT800 is available on request or by drawing note.
Advantages
- High strength — 700 MPa (102 ksi), better than 92% of stainless steel grades
Limitations
- Limited service temperature — 350°C (662 °F), worse than 84% of stainless steel grades
- Limited ductility — 18%, worse than 83% of stainless steel grades
1.4422 +QT800 properties
Typical room-temperature values for 1.4422 +QT800; 22 are specific to this condition. Other listed values are 1.4422 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4422 +QT800 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4422 +QT800 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4422 +QT800 is rated for continuous service to 350°C (662 °F). It conducts heat at 15.5 W/m·K (8.96 BTU/hr·ft·°F), better than 53% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
1.4422 +QT800 conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4422 +QT800 takes about 55 MJ of energy and emits 5.4 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
1.4422 +QT800's machinability is fair (40/100, better than 72% of stainless steel grades); weldability very good (78/100); formability fair (38/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4422 +QT800
Is 1.4422 easy to machine?
Machines like a 30 HRC tough stainless: rigid setups, sharp coated carbide, positive rake, 60–110 m/min, generous feed and coolant to avoid work hardening and built-up edge.
Can 1.4422 be welded?
Very good for a martensitic grade thanks to ≤0.03 %C — GTAW/GMAW/SAW with matching 12-5-2 or over-alloyed duplex/super-duplex filler, preheat 100–150 °C for thick sections and PWHT at 600–650 °C to temper the HAZ.
Can 1.4422 be formed, bent or molded?
Hot forge/roll at 1100–1150 °C with slow cooling; cold forming is limited in QT condition, so bend and form in the annealed state and re-quench-and-temper.
What surface finishes work on 1.4422?
Passivate in nitric or citric acid after machining and pickle/blast weld scale; polishes to a bright finish, and hard chrome, nitriding or PVD can be applied where wear resistance is needed.
1.4422 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cultra-low carbon (X1 designation) | ≤ 0.03 | 0.02 |
| Si | ≤ 0.7 | 0.35 |
| Mn | ≤ 2 | 0.8 |
| P | ≤ 0.03 | 0.02 |
| Slow S for weldability and toughness | ≤ 0.01 | 0 |
| Cr | 11 – 13 | 12 |
| Ni | 4.5 – 6 | 5.2 |
| Mo | 1.5 – 2.5 | 2 |
| Cu | 0.3 – 1 | 0.6 |
| N | ≤ 0.03 | 0.02 |
| Fe | balance | — |
1.4422 +QT800 — frequently asked
What is 1.4422 +QT800 used for?
1.4422 +QT800 is typically used for pump components, food processing equipment and marine hardware. In short: weldable martensitic stainless; soft martensitic pump grade; 780 MPa yield, 31 HRC.
What is the yield strength of 1.4422 +QT800?
1.4422 +QT800 has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 92% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 1.4422 +QT800 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machines like a 30 HRC tough stainless: rigid setups, sharp coated carbide, positive rake, 60–110 m/min, generous feed and coolant to avoid work hardening and built-up edge.
Can 1.4422 +QT800 be welded?
Yes — weldability is rated very good (78/100). Very good for a martensitic grade thanks to ≤0.03 %C — GTAW/GMAW/SAW with matching 12-5-2 or over-alloyed duplex/super-duplex filler, preheat 100–150 °C for thick sections and PWHT at 600–650 °C to temper the HAZ.
What surface finishes work on 1.4422 +QT800?
Passivate in nitric or citric acid after machining and pickle/blast weld scale; polishes to a bright finish, and hard chrome, nitriding or PVD can be applied where wear resistance is needed.
Can 1.4422 +QT800 be formed, bent or molded?
Hot forge/roll at 1100–1150 °C with slow cooling; cold forming is limited in QT condition, so bend and form in the annealed state and re-quench-and-temper.
What is the maximum service temperature of 1.4422 +QT800?
1.4422 +QT800 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4422 +QT900 and 1.4422-AW?
+QT900 is the default condition — standard stocked condition: best strength/toughness balance for pump and compressor shafts, impellers and marine hardware. AW: reference condition for matching-consumable welds before post-weld tempering; a 600–650 °C PWHT restores toughness. Yield strength is 780 MPa in +QT900 versus 700 MPa in AW.
Sources
- EN 10088-3 Stainless steels — Semi-finished products, bars, rods, sections — CEN (2014)
- EN 10088-1 Stainless steels — List of stainless steels — CEN (2014)
- Soft-martensitic / supermartensitic 12Cr-5Ni-2Mo stainless bar datasheet — Deutsche Edelstahlwerke (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.