Stainless Steel 1.4411 QT-SOUR
Hardness band
EN 1.4411
QT-SOUR = qT ≤23 HRC
Over-tempered variant used where NACE MR0175/ISO 15156 hardness limits apply to wetted castings.
Values for the QT-SOUR condition
Other 1.4411 tempers and conditions
1.4411 is listed in 6 conditions; see the grade overview at 1.4411.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
QT-SOURThis page QT ≤23 HRC | Over-tempered variant used where NACE MR0175/ISO 15156 hardness limits apply to wetted castings. | 570 | 790 | 20 | 21 HRC | 2.2 % IACS |
QT1Default Austenitized ~1020 °C, air quenched, double tempered ~600–620 °C | Standard delivery condition of EN 10283/EN 10213 castings — best balance of 540 MPa+ yield, high impact toughness and weld repairability. | 620 | 850 | 18 | 28 HRC | — |
hot isostatically pressed casting, then quenched and tempered | Specified for fatigue-critical or radiographically strict castings; HIP closes microporosity and lifts ductility/toughness. | 640 | 880 | 21 | 29 HRC | 2.2 % IACS |
Quenched and tempered at lower temperature for higher strength | Pick when higher yield is required for shafts, runner blades or highly loaded valve internals and some toughness can be traded away. | 800 | 980 | 14 | 34 HRC | 2.2 % IACS |
Spheroidize annealed | Intermediate foundry condition only — hard untempered martensite, low toughness; never ship in this state. | 850 | 1,150 | 8 | 41 HRC | 2.2 % IACS |
Hardened | Hardened but untempered stage of the QT cycle; used only as an intermediate before tempering or for hardness reference. | 950 | 1,250 | 7 | 44 HRC | 2.2 % IACS |
What is 1.4411 QT-SOUR?
1.4411 QT-SOUR is 1.4411 heat treated to QT-SOUR — over-tempered variant used where NACE MR0175/ISO 15156 hardness limits apply to wetted castings. 1.4411 QT-SOUR has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi). 1.4411 QT-SOUR 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). QT1 is the default condition FabDigit quotes; QT-SOUR is available on request or by drawing note.
Advantages
- High strength — 570 MPa (82.7 ksi), better than 85% of stainless steel grades
Limitations
- Limited formability — 14/100, worse than 92% of stainless steel grades
- Limited service temperature — 350°C (662 °F), worse than 84% of stainless steel grades
- Limited ductility — 20%, worse than 79% of stainless steel grades
1.4411 QT-SOUR properties
Typical room-temperature values for 1.4411 QT-SOUR; 23 are specific to this condition. Other listed values are 1.4411 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4411 QT-SOUR 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
1.4411 QT-SOUR has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4411 QT-SOUR is rated for continuous service to 350°C (662 °F). It conducts heat at 17.5 W/m·K (10.1 BTU/hr·ft·°F), better than 72% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4411 QT-SOUR conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4411 QT-SOUR takes about 55 MJ of energy and emits 4.2 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
1.4411 QT-SOUR's machinability is fair (42/100, better than 79% of stainless steel grades); weldability very good (75/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4411 QT-SOUR
Is 1.4411 easy to machine?
Machine in the tempered condition with rigid setups, sharp carbide (or ceramic-free) tooling, moderate speed and heavy positive feed to cut under the work-hardened skin; flood coolant and avoid dwelling.
Can 1.4411 be welded?
Weld with matching low-carbon 16-5-2 or over-alloyed 309LMo/duplex filler, 100–160 °C preheat and interpass control, then a post-weld temper at ~590–620 °C to restore toughness in the HAZ.
Can 1.4411 be formed, bent or molded?
Sand or investment cast with generous feeding on heavy sections; no cold forming — reshaping is done by hot work above 1000 °C followed by the full quench-and-double-temper cycle.
What surface finishes work on 1.4411?
Grind/blast, then pickle and passivate (nitric or citric) to restore the passive film; can be electropolished or mirror-polished for cavitation-resistant hydraulic surfaces, and accepts hard-chrome or thermal-spray overlays.
1.4411 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 |
|---|---|---|
| Clow carbon keeps martensite soft and weldable | ≤ 0.06 | 0.04 |
| Si | ≤ 0.8 | 0.5 |
| Mn | ≤ 1 | 0.7 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 15 – 17 | 16 |
| Ni | 4 – 6 | 5 |
| Modistinguishes 1.4411 from 1.4405 (0.7–1.5 Mo) | 1.5 – 2 | 1.7 |
| Nproducer practice; not always specified | ≤ 0.06 | 0.03 |
| Fe | balance | — |
1.4411 QT-SOUR — frequently asked
What is 1.4411 QT-SOUR used for?
1.4411 QT-SOUR is typically used for high-head hydraulic turbine runners, offshore pump castings and seawater-handling components. In short: highest-Mo soft martensitic; sour-service capable casting; best pitting resistance here.
What is the yield strength of 1.4411 QT-SOUR?
1.4411 QT-SOUR has a typical yield strength of 570 MPa (82.7 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 85% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1.4411 QT-SOUR easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine in the tempered condition with rigid setups, sharp carbide (or ceramic-free) tooling, moderate speed and heavy positive feed to cut under the work-hardened skin; flood coolant and avoid dwelling.
Can 1.4411 QT-SOUR be welded?
Yes — weldability is rated very good (75/100). Weld with matching low-carbon 16-5-2 or over-alloyed 309LMo/duplex filler, 100–160 °C preheat and interpass control, then a post-weld temper at ~590–620 °C to restore toughness in the HAZ.
What surface finishes work on 1.4411 QT-SOUR?
Grind/blast, then pickle and passivate (nitric or citric) to restore the passive film; can be electropolished or mirror-polished for cavitation-resistant hydraulic surfaces, and accepts hard-chrome or thermal-spray overlays.
Can 1.4411 QT-SOUR be formed, bent or molded?
Sand or investment cast with generous feeding on heavy sections; no cold forming — reshaping is done by hot work above 1000 °C followed by the full quench-and-double-temper cycle.
What is the maximum service temperature of 1.4411 QT-SOUR?
1.4411 QT-SOUR 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 1.4411-QT1 and 1.4411-H?
QT1 is the default condition — standard delivery condition of EN 10283/EN 10213 castings — best balance of 540 MPa+ yield, high impact toughness and weld repairability. H: hardened but untempered stage of the QT cycle; used only as an intermediate before tempering or for hardness reference. Yield strength is 620 MPa in QT1 versus 950 MPa in H.
Sources
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASTM A743/A743M — Castings, Iron-Chromium-Nickel corrosion resistant (CA6NM family reference) — ASTM (2019)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- Soft-martensitic cast stainless steel data (16Cr-5Ni-Mo hydro and pump castings) — Steel foundry datasheets (2022)
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.