Stainless Steel 1.4923 +QT1
Heat-treated state · default condition
EN 1.4923
+QT1 = hardened and high-temperature tempered, Rm 800–950 MPa
Standard creep-service condition for steam-turbine bolting and high-temperature fasteners; best toughness/relaxation balance.
Values for the +QT1 condition
Other 1.4923 tempers and conditions
1.4923 is listed in 3 conditions; see the grade overview at 1.4923.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Delivery condition for bar/forging stock that will be machined rough and then hardened and tempered by the fabricator. | 450 | 720 | 20 | 20 HRC | — |
+QT1DefaultThis page Hardened and high-temperature tempered, Rm 800–950 MPa | Standard creep-service condition for steam-turbine bolting and high-temperature fasteners; best toughness/relaxation balance. | 680 | 880 | 17 | 27 HRC | — |
Hardened and tempered to higher strength, Rm 900–1050 MPa | Choose when higher proof stress (Rp0.2 ≥ 700 MPa) is required for bolting or blades, accepting lower ductility and toughness. | 780 | 970 | 15 | 31 HRC | — |
What is 1.4923 +QT1?
1.4923 +QT1 is 1.4923 heat treated to +QT1 — standard creep-service condition for steam-turbine bolting and high-temperature fasteners; best toughness/relaxation balance. 1.4923 +QT1 has a yield strength of 680 MPa (98.6 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 91% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 216 GPa (31.3 Msi). 1.4923 +QT1 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,420°C (2,588 °F).
Advantages
- High electrical conductivity — 3 % IACS, better than 95% of stainless steel grades
- Low embodied carbon — 3.2 kg CO₂/kg, better than 95% of stainless steel grades
- High strength — 680 MPa (98.6 ksi), better than 91% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Needs corrosion protection — 42/100, worse than 90% of stainless steel grades
- Difficult to weld — 30/100, worse than 88% of stainless steel grades
- Limited ductility — 17%, worse than 86% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Low fracture toughness — 80 MPa·√m (72.8 ksi·√in), worse than 79% of stainless steel grades
1.4923 +QT1 properties
Typical room-temperature values for 1.4923 +QT1; 18 are specific to this condition. Other listed values are 1.4923 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4923 +QT1 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
1.4923 +QT1 has a yield strength of 680 MPa (98.6 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 91% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 216 GPa (31.3 Msi).
Thermal6
1.4923 +QT1 is rated for continuous service to 550°C (1,022 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
1.4923 +QT1 conducts electricity at 3 % IACS, better than 95% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (42/100), worse than 90% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4923 +QT1 takes about 46 MJ of energy and emits 3.2 kg of CO₂ — less than 88% of stainless steel grades. Typical recycled content is 55%.
Manufacturability8
1.4923 +QT1's machinability is fair (35/100, better than 51% of stainless steel grades); weldability poor (30/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4923 +QT1
Is 1.4923 easy to machine?
Machine in the +A or fully tempered condition with rigid setups, sharp carbide tooling, low speed and generous coolant; work-hardening and poor chip breaking make it roughly one-third as machinable as 1212.
Can 1.4923 be welded?
Weldable with matching 12CrMoV or Cr-Mo filler using 250–350 °C preheat, controlled interpass and mandatory post-weld temper at 700–750 °C to avoid untempered martensite cracking.
Can 1.4923 be formed, bent or molded?
Hot work at 1100–850 °C followed by slow cooling and annealing; cold forming is limited to minor straightening because of the high tempered-martensite strength.
What surface finishes work on 1.4923?
Passivate or grind/polish after heat treatment; anodizing is not applicable — nitriding, chrome plating or high-temperature anti-seize coatings are used for bolting.
1.4923 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 | 0.18 – 0.24 | 0.21 |
| Si | ≤ 0.5 | 0.3 |
| Mn | 0.4 – 0.9 | 0.6 |
| Pimpurity | ≤ 0.03 | — |
| Simpurity | ≤ 0.02 | — |
| Cr | 11 – 12.5 | 11.8 |
| Mo | 0.8 – 1.2 | 1 |
| Ni | 0.3 – 0.8 | 0.55 |
| V | 0.25 – 0.35 | 0.3 |
| Fe | balance | — |
1.4923 +QT1 — frequently asked
What is 1.4923 +QT1 used for?
1.4923 +QT1 is typically used for steam turbine bolts and studs, turbine rotor discs, high-temperature valve stems and power plant fasteners. In short: standard 12Cr bolting steel; 680 MPa yield to 550 °C; requires post-weld temper.
What is the yield strength of 1.4923 +QT1?
1.4923 +QT1 has a typical yield strength of 680 MPa (98.6 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 91% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.4923 +QT1 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine in the +A or fully tempered condition with rigid setups, sharp carbide tooling, low speed and generous coolant; work-hardening and poor chip breaking make it roughly one-third as machinable as 1212.
Can 1.4923 +QT1 be welded?
Not readily — weldability is rated poor (30/100). Weldable with matching 12CrMoV or Cr-Mo filler using 250–350 °C preheat, controlled interpass and mandatory post-weld temper at 700–750 °C to avoid untempered martensite cracking.
What surface finishes work on 1.4923 +QT1?
Passivate or grind/polish after heat treatment; anodizing is not applicable — nitriding, chrome plating or high-temperature anti-seize coatings are used for bolting.
Can 1.4923 +QT1 be formed, bent or molded?
Hot work at 1100–850 °C followed by slow cooling and annealing; cold forming is limited to minor straightening because of the high tempered-martensite strength.
What is the maximum service temperature of 1.4923 +QT1?
1.4923 +QT1 is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties — CEN (2013)
- EN 10088-3 — Stainless steels: technical delivery conditions for semi-finished products, bars, rods — CEN (2014)
- DIN 17240 — Heat resisting and highly heat resisting materials for bolts and nuts — DIN (1976)
- GB/T 1221 / GB/T 8732 (1Cr12MoV ) — SAC (2007)
- 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)
- X22CrMoV12-1 (1.4923) turbine bolting steel datasheet — European special steel producers (2022)
- 1Cr12MoV — Mysteel / 1688 (2025)
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.