Stainless Steel 1.4905-QT (Quenched and tempered)
Heat-treated state
EN 1.4905
Used for thick turbine/valve forgings where accelerated cooling is needed to obtain full martensite through-section.
Values for the QT condition
Other 1.4905 tempers and conditions
1.4905 is listed in 5 conditions; see the grade overview at 1.4905.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Intermediate machining/forming condition for bar and forging stock; must be re-normalized and tempered before service. | 400 | 620 | 25 | 200 HB | — |
NTDefault normalized (1040–1090 °C) and tempered (730–780 °C) | Standard delivery condition for tubes, pipe and plate; tempered martensite giving the certified creep and impact properties. | 520 | 700 | 22 | 20 HRC | — |
QTThis page Quenched and tempered | Used for thick turbine/valve forgings where accelerated cooling is needed to obtain full martensite through-section. | 560 | 750 | 20 | 22 HRC | 3 % IACS |
As-welded deposit | Condition of matching E911 weld deposits before the mandatory 750–770 °C PWHT; hard, low-toughness, never left in service. | 800 | 1,000 | 10 | 40 HRC | 2.8 % IACS |
Normalized | Transient condition after normalizing or after welding — hard and brittle; tempering at 730–780 °C is mandatory before use. | 900 | 1,250 | 10 | 43 HRC | 2.8 % IACS |
What is 1.4905-QT?
1.4905-QT is 1.4905 heat treated to QT — used for thick turbine/valve forgings where accelerated cooling is needed to obtain full martensite through-section. 1.4905-QT has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 218 GPa (31.6 Msi). 1.4905-QT has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,420°C (2,588 °F). NT is the default condition FabDigit quotes; QT is available on request or by drawing note.
Advantages
- Low embodied carbon — 2.9 kg CO₂/kg, better than 98% of stainless steel grades
- Conducts heat well — 26 W/m·K (15 BTU/hr·ft·°F), better than 96% of stainless steel grades
- High electrical conductivity — 3 % IACS, better than 95% of stainless steel grades
- High strength — 560 MPa (81.2 ksi), better than 85% of stainless steel grades
Limitations
- Needs corrosion protection — 30/100, worse than 99% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Difficult to weld — 40/100, worse than 83% of stainless steel grades
- Limited formability — 22/100, worse than 82% of stainless steel grades
- Limited ductility — 20%, worse than 79% of stainless steel grades
1.4905-QT properties
Typical room-temperature values for 1.4905-QT; 23 are specific to this condition. Other listed values are 1.4905 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4905-QT has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
1.4905-QT has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 218 GPa (31.6 Msi).
Thermal6
1.4905-QT is rated for continuous service to 600°C (1,112 °F). It conducts heat at 26 W/m·K (15 BTU/hr·ft·°F), better than 96% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
1.4905-QT conducts electricity at 3 % IACS, better than 95% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), worse than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4905-QT takes about 36 MJ of energy and emits 2.9 kg of CO₂ — less than 99% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
1.4905-QT's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability fair (40/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4905-QT
Is 1.4905 easy to machine?
Machine in the annealed or tempered condition with rigid setups, sharp carbide tooling, low speed/high feed and copious coolant — work-hardening and poor chip-breaking make it slower than plain alloy steel.
Can 1.4905 be welded?
Use matching E911/9Cr-1Mo-W consumables with 200–300 °C preheat/interpass, control interpass below ~350 °C, cool to ~100 °C before the mandatory 750–770 °C PWHT to restore toughness.
Can 1.4905 be formed, bent or molded?
Hot form at 1100–900 °C followed by full re-normalizing and tempering; cold bending is limited and requires post-form stress relief.
What surface finishes work on 1.4905?
Not corrosion resistant in wet service — protect with paint, aluminizing or chromizing; pickle/passivate only per boiler-cleaning practice.
1.4905 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 |
|---|---|---|
| C | 0.09 – 0.13 | 0.11 |
| Si | 0.1 – 0.5 | 0.2 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.02 | — |
| S | ≤ 0.01 | — |
| Cr | 8.5 – 9.5 | 9 |
| Mo | 0.9 – 1.1 | 1 |
| W | 0.9 – 1.1 | 1 |
| V | 0.18 – 0.25 | 0.22 |
| Nb | 0.06 – 0.1 | 0.08 |
| N | 0.05 – 0.09 | 0.07 |
| Ni | ≤ 0.4 | 0.2 |
| Almax, soluble Al | ≤ 0.02 | — |
| Bmax (residual) | ≤ 5×10⁻⁴ | — |
| Fe | balance | — |
1.4905-QT — frequently asked
What is 1.4905-QT used for?
1.4905-QT is typically used for steam turbine rotors, boiler tubes and headers, high-temperature bolting and power plant piping. In short: 9Cr creep-resistant steel; 600 °C steam service; mandatory post-weld heat treatment.
What is the yield strength of 1.4905-QT?
1.4905-QT has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 85% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4905-QT easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Machine in the annealed or tempered condition with rigid setups, sharp carbide tooling, low speed/high feed and copious coolant — work-hardening and poor chip-breaking make it slower than plain alloy steel.
Can 1.4905-QT be welded?
With care — weldability is rated fair (40/100). Use matching E911/9Cr-1Mo-W consumables with 200–300 °C preheat/interpass, control interpass below ~350 °C, cool to ~100 °C before the mandatory 750–770 °C PWHT to restore toughness.
What surface finishes work on 1.4905-QT?
Not corrosion resistant in wet service — protect with paint, aluminizing or chromizing; pickle/passivate only per boiler-cleaning practice.
Can 1.4905-QT be formed, bent or molded?
Hot form at 1100–900 °C followed by full re-normalizing and tempering; cold bending is limited and requires post-form stress relief.
What is the maximum service temperature of 1.4905-QT?
1.4905-QT is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4905-NT and 1.4905-N?
NT is the default condition — standard delivery condition for tubes, pipe and plate; tempered martensite giving the certified creep and impact properties. N: transient condition after normalizing or after welding — hard and brittle; tempering at 730–780 °C is mandatory before use. Yield strength is 520 MPa in NT versus 900 MPa in N.
Sources
- EN 10216-2 — Seamless steel tubes for pressure purposes, non-alloy and alloy steels with specified elevated temperature properties — CEN (2020)
- EN 10222-2 — Steel forgings for pressure purposes, ferritic and martensitic steels for elevated temperature — CEN (2017)
- VdTÜV-Werkstoffblatt 522 — X11CrMoWVNb9-1 (E911) — VdTÜV (2004)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Creep-strength enhanced ferritic (CSEF) steel property compilations for P91/P92/E911 — EPRI / ECCC (2018)
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.