Quick Reference: 19CrMoVNbN11-1 (1.4913) Steel — What You Need to Know
19CrMoVNbN11-1 (also written as EN 1.4913 or X19CrMoNbVN11-1) is a martensitic creep-resistant steel containing 10–11.5% chromium, plus molybdenum, vanadium, niobium, nitrogen, and trace boron. It is the industry standard for steam turbine blades, rotor shafts, and valve spindles in power plants operating at 540–600°C.
After quenching and tempering (+QT), it delivers tensile strength ≥900 MPa, proof stress ≥700 MPa, and a 100,000-hour creep rupture strength of approximately 95 MPa at 600°C. It is standardized under EN 10269:2013 and EN 10302:2008. There is no direct ASTM equivalent — specify by EN designation on all non-European projects.
Manufactured as open die forgings and seamless rings by Jiangsu Liangyi Co., Limited (ISO 9001:2015 certified, est. 1997, Jiangyin, Jiangsu, China) in components from 30 kg to 30 tonnes. Full EN 10204 3.1/3.2 mill test certificates are supplied with all deliveries. View the full product page →
Overview and Naming Conventions
19CrMoVNbN11-1 is a high-alloy martensitic creep-resistant steel in the 11–12% chromium family, developed specifically for high-temperature power plant components operating at 540–600°C. Under the European steel classification system (EN 10027-1 and EN 10027-2), it carries two official designations referring to exactly the same alloy:
- Numerical designation (EN material number): 1.4913
- Symbolic designation: X19CrMoNbVN11-1
Any technical datasheet, mill test certificate, or procurement document using either form refers to precisely the same chemical composition and property requirements. The "19" in the name reflects the nominal carbon content (~0.17–0.21% C × 100), while "11-1" encodes the chromium and molybdenum group contents in the EN symbolic system.
The grade was developed to fill the performance gap between conventional 9–10% Cr steels (P91, P92) and austenitic stainless steels for steam-side components at 540–600°C. Its 11% chromium level delivers substantially better steam oxidation resistance than 9Cr grades, while maintaining full martensitic hardenability and a thermal expansion coefficient (~10.5–12.0 × 10⁻⁶/K) that is compatible with ferritic piping systems — a critical advantage over austenitic grades (~16–18 × 10⁻⁶/K) in dissimilar metal joints.
19CrMoVNbN11-1 is compositionally distinct from 1.4922 (X20CrMoV11-1) and 1.4926 (X21CrMoV12-1) by virtue of its niobium and nitrogen additions, which generate fine MX-type carbide/nitride precipitates. These precipitates are the primary mechanism behind its superior long-term creep performance compared to older 12Cr grades.
Chemical Composition
The following composition limits apply per EN 10269:2013 and EN 10302:2008. All values in mass percent (wt%).
| Element | Min % | Max % | Typical % | Primary Role in Steel |
|---|---|---|---|---|
| Carbon (C) | 0.17 | 0.21 | 0.19 | Martensite formation; base strength contributor |
| Silicon (Si) | — | 0.50 | 0.30 | Deoxidation; steam oxidation resistance |
| Manganese (Mn) | 0.40 | 0.80 | 0.60 | Sulfide morphology control; hardenability |
| Phosphorus (P) | — | 0.030 | <0.020 | Impurity — grain boundary embrittler; control critical |
| Sulfur (S) | — | 0.015 | <0.005 | Impurity — reduces toughness and ductility |
| Chromium (Cr) | 10.00 | 11.50 | 10.8 | Steam oxidation & corrosion resistance; primary carbide former |
| Molybdenum (Mo) | 0.60 | 0.90 | 0.75 | Solid-solution strengthening; carbide stability |
| Vanadium (V) | 0.25 | 0.35 | 0.30 | Fine V(C,N) MX precipitate nucleation; creep strengthening |
| Niobium (Nb) | 0.060 | 0.10 | 0.08 | Nb(C,N) precipitates; prior austenite grain refinement |
| Nitrogen (N) | 0.030 | 0.080 | 0.055 | Austenite stabiliser; drives MX nitride density |
| Boron (B) | — | 0.0015 | 0.0008 | Grain boundary segregation; suppresses long-term creep damage |
| Nickel (Ni) | — | 0.40 | 0.25 | Toughness; residual — not intentionally alloyed |
| Aluminum (Al) | — | 0.040 | <0.020 | Deoxidation; AlN formation must be minimized |
Always specify both the EN composition limits and the required heat treatment condition (+QT) on your purchase order. Composition alone does not define the delivered mechanical properties — the austenitizing and tempering temperatures are critical controlled variables that determine the final creep performance of the forging. For full dimensional availability and weight range of custom open die forgings in 19CrMoVNbN11-1, see the product page.
Microstructure and Strengthening Mechanisms
In the quenched-and-tempered (+QT) condition, 19CrMoVNbN11-1 exhibits a fully tempered martensitic microstructure. Three synergistic strengthening mechanisms explain why this grade outperforms older 12Cr steels at service temperatures above 550°C.
1. MX-Type Precipitate Hardening
Combined additions of vanadium, niobium, and nitrogen promote fine MX-type carbonitrides — where M represents V or Nb and X represents C or N. These nanometre-scale precipitates (typically 5–20 nm in diameter) form during tempering at 720–780°C and remain thermodynamically stable up to approximately 620°C. Their critical function is dislocation pinning: they resist dislocation climb and glide at elevated temperatures, directly opposing the primary creep deformation mechanism. MX precipitate number density and size distribution are strongly sensitive to tempering time and temperature — a key reason precise heat treatment control is mandatory.
2. Boron Grain Boundary Segregation
The trace boron addition (max. 0.0015 wt%) produces a disproportionately large microstructural benefit. During tempering, boron atoms preferentially migrate to prior austenite grain boundaries, where they suppress grain boundary sliding — the dominant damage mechanism at elevated homologous temperatures. This effect becomes especially significant beyond 50,000 service hours, where boron-free steels suffer accelerating creep rates driven by grain boundary cavitation and void formation.
3. Solid-Solution Strengthening
Molybdenum (0.6–0.9%) and chromium dissolved in the tempered martensitic matrix provide baseline solid-solution strengthening that operates across all service temperatures. The Mo content is deliberately maintained below the level that would promote delta-ferrite formation during austenitization, which would severely compromise long-term creep ductility and fracture toughness.
The synergy between MX precipitates and boron in 19CrMoVNbN11-1 is why the grade maintains ~95 MPa creep rupture stress at 600°C for 100,000 hours — a performance level that older 12Cr steels without Nb+N additions (such as X20CrMoV11-1 / 1.4922) cannot achieve with the same chromium content.
Mechanical Properties (+QT Condition)
Minimum guaranteed room-temperature mechanical properties in the quenched and tempered (+QT) condition per EN 10269:2013, for forged sections ≤ 250 mm.
Elevated-Temperature Tensile Properties
| Temp. (°C) | Rp0.2 min (MPa) | Rm min (MPa) | Elongation A (%) |
|---|---|---|---|
| 20 | ≥ 700 | 900–1100 | ≥ 14 |
| 200 | ≥ 580 | ≥ 750 | ≥ 14 |
| 300 | ≥ 540 | ≥ 700 | ≥ 14 |
| 400 | ≥ 490 | ≥ 640 | ≥ 15 |
| 500 | ≥ 430 | ≥ 560 | ≥ 15 |
| 550 | ≥ 390 | ≥ 510 | ≥ 16 |
| 600 | ≥ 340 | ≥ 430 | ≥ 16 |
Note: Values are indicative minimums per EN 10302 property tables. Certified values appear on the EN 10204 3.1/3.2 mill test certificate for each specific production heat. Jiangsu Liangyi supplies certified 1.4913 forging parts with EN 10204 3.1/3.2 MTC as standard for every delivery.
Creep Rupture Strength
Creep rupture strength is the primary material selection criterion for 19CrMoVNbN11-1 in high-temperature power plant applications. Values below represent approximate mean 50% probability rupture stresses at stated temperature and exposure duration.
| Temperature (°C) | 10,000 h | 30,000 h | 100,000 h | 200,000 h |
|---|---|---|---|---|
| 500 | ~300 | ~260 | ~210 | ~185 |
| 540 | ~230 | ~195 | ~155 | ~135 |
| 560 | ~200 | ~165 | ~130 | ~112 |
| 580 | ~165 | ~132 | ~103 | ~88 |
| 600 | ~130 | ~105 | ~95 | ~78 |
| 620 | ~95 | ~76 | ~60 | ~50 |
Source: Interpolated from EN 10302:2008 and ECCC Data Sheets for 1.4913. For structural design, use lower confidence-bound values as required by the applicable pressure vessel or turbine design code (e.g., EN 13480, TRD, ASME).
Comparison with Related Grades at 600°C / 100,000 Hours
Despite P91 showing slightly higher 100,000-hour rupture stress at 600°C, 1.4913 is often preferred for rotating components in European power plants: it offers superior steam oxidation resistance (11% Cr vs 9% Cr), decades of EN-certified fleet service data, and a thermal expansion coefficient fully compatible with ferritic piping systems — reducing long-term maintenance costs.
Physical Properties
| Property | 20°C | 200°C | 400°C | 600°C | Unit |
|---|---|---|---|---|---|
| Density | 7.72 | 7.68 | 7.61 | 7.53 | g/cm³ |
| Thermal conductivity | 27.5 | 27.0 | 26.4 | 25.8 | W/(m·K) |
| Specific heat capacity | 480 | 510 | 560 | 640 | J/(kg·K) |
| Mean CTE (from 20°C) | — | 10.5 | 11.2 | 12.0 | ×10⁻⁶/K |
| Young's modulus | 215 | 205 | 190 | 165 | GPa |
| Electrical resistivity | 0.70 | 0.82 | 0.95 | 1.10 | µΩ·m |
The CTE of 1.4913 (~10.5–12.0 × 10⁻⁶/K) is far lower than austenitic stainless steels (~16–18 × 10⁻⁶/K), making it thermally compatible with ferritic low-alloy piping in mixed-material systems. This compatibility eliminates thermally-induced stresses at dissimilar metal welds that would otherwise shorten component life in all-austenitic designs operating through large temperature cycles.
Heat Treatment Requirements
All 19CrMoVNbN11-1 forgings must be delivered in the fully quenched and tempered (+QT) condition. The heat treatment sequence directly controls the density and distribution of MX precipitates that govern creep life over 100,000+ service hours.
PWHT for 1.4913 weld joints must be performed at 720–760°C for a minimum of 2 hours. Do not transfer PWHT parameters from P91 procedures (ASME B31.1 minimum 760°C) — the slightly higher P91 PWHT temperature risks over-tempering 1.4913 and reducing its ambient-temperature strength below the EN 10269 minimum of 900 MPa Rm.
Welding Guide for 19CrMoVNbN11-1
Preheat and Interpass Temperature Requirements
| Parameter | Requirement | Technical Rationale |
|---|---|---|
| Preheat temperature | 200–250°C | Required for all section sizes; prevents hydrogen-induced cold cracking in the HAZ |
| Interpass temperature | Max. 300°C | Exceeding causes microstructural coarsening and reduces HAZ toughness |
| Post-weld cooling hold | Cool to 80–100°C | Ensures complete martensite transformation across the full weld cross-section before PWHT |
| PWHT temperature | 720–760°C | Minimum 2 h; proportional increase with section thickness |
| PWHT heating/cooling rate | Max. 80°C/h (above 400°C) | Controlled to minimise thermal gradient stresses in large-section forgings |
Recommended Filler Materials by Process
| Process | Filler Classification | Key Considerations |
|---|---|---|
| GTAW (TIG) | W ZCrMo11-1V | Preferred for root passes; lowest hydrogen risk; use pure Ar shielding |
| SMAW (MMA) | E ZCrMo11-1V B 4 2 H5 | Low-hydrogen basic coated electrode mandatory; rebake at 300°C/1 h before use |
| GMAW (MIG/MAG) | G ZCrMo11-1V | Shield gas: Ar + 2% CO₂ or Ar + 2% O₂; avoid high CO₂ mixtures |
| SAW | S ZCrMo11-1V | Basic flux required; rebake flux at 350°C/2 h before use; monitor basicity index |
Machining Parameters
In the +QT condition (265–330 HB), 19CrMoVNbN11-1 machines comparably to medium-hardness alloy steels. The following are recommended starting-point parameters for CNC operations using coated carbide tooling.
| Operation | Speed (m/min) | Feed (mm/rev) | Depth of Cut (mm) | Coolant |
|---|---|---|---|---|
| Rough turning | 80–120 | 0.30–0.50 | 3–8 | Flood coolant required |
| Finish turning | 120–180 | 0.10–0.20 | 0.5–1.5 | Flood coolant required |
| Face milling | 80–140 | 0.12–0.20/tooth | 2–5 | Flood or MQL |
| Drilling | 20–40 | 0.08–0.15 | Full diameter | High-pressure through-tool |
| Tapping | 5–12 | Thread pitch | Full thread depth | Tapping fluid essential |
Use CVD- or PVD-coated carbide inserts (ISO grade P25–P40) for turning. Dry machining is not recommended — the work-hardening tendency of 1.4913 and its relatively low thermal conductivity make sustained dry cutting impractical. Ceramic inserts are not recommended for interrupted cuts or forged surfaces with scale.
Corrosion and Oxidation Resistance
Steam Oxidation Performance (High Temperature)
The 11% chromium content of 19CrMoVNbN11-1 forms a dense, adherent Cr₂O₃-dominated oxide scale in steam environments up to 600°C. This self-limiting scale provides significantly better protection than 9Cr grades such as P91 and P92, which develop less protective Fe₂O₃-rich scales above 550°C. In operational ultra-supercritical (USC) boilers, 1.4913 has demonstrated acceptable steam oxidation mass gain rates at 600°C over 200,000-hour service exposures, making it a long-term maintenance-efficient choice for steam-side components.
Aqueous and Atmospheric Corrosion (Ambient Conditions)
19CrMoVNbN11-1 is not a corrosion-resistant stainless steel in the conventional sense. In ambient or outdoor conditions it will rust if unprotected. All storage, transport, and pre-commissioning periods require appropriate protection: barrier coatings, vapor corrosion inhibitor (VCI) packaging, or controlled dry storage environments. This grade is not suitable for acid service, chloride, saline, or permanently wet environments.
Some specifications list 1.4913 under EN 10088 (stainless steel standards) because its Cr content exceeds 10.5%. This is technically correct but operationally misleading — in ambient humidity or outdoor service, 19CrMoVNbN11-1 will corrode and must be engineered and protected as an alloy steel, not a stainless steel, in all non-operating conditions.
International Grade Equivalents
19CrMoVNbN11-1 has no direct ASTM or ASME equivalent. It was developed within the European EN standards framework. When ordering on non-European projects, always specify as EN 1.4913 and require EN 10204 3.1 or 3.2 mill test certificates from the forging manufacturer for full material traceability.
| Standard System | Designation | Equivalence Status |
|---|---|---|
| EN (Europe) | 1.4913 / X19CrMoNbVN11-1 | Exact — primary specification standard (EN 10269, EN 10302) |
| ASTM / ASME (USA) | No direct equivalent | P91 is 9Cr — different family; specify by EN on all US-regulated projects |
| DIN (Germany, historical) | X20CrMoNiV11-1 | Predecessor — no Nb or N addition; older grade, not a current substitute |
| GB / YB (China) | No standardised equivalent | Import via EN 1.4913 specification with EN 10204 MTC from supplier |
| JIS (Japan) | No direct equivalent | Specify by EN designation on all Japanese-regulated projects |
| GOST (Russia) | No direct equivalent | 15Kh11MF is lower-alloy 12Cr — not interchangeable with 1.4913 |
| BS (UK) | Formerly BS En 56D (withdrawn) | Use EN 1.4913 on all UK / PED-governed projects |
Industrial Applications of 19CrMoVNbN11-1 Forgings
19CrMoVNbN11-1 is specified wherever engineers require the simultaneous combination of high creep rupture strength, steam oxidation resistance, and thermal expansion compatibility with ferritic piping at temperatures of 540–600°C. Jiangsu Liangyi manufactures 1.4913 forged bars, rings, and shafts to custom dimensions from 30 kg to 30 tonnes, fully heat-treated and certified to EN standards.
Steam Turbine Blades
LP and IP turbine blades in coal-fired and combined-cycle power plants at 540–600°C. The primary global application of 1.4913 forgings.
Turbine Rotor Shafts
Large open-die forged rotor discs and shaft sections for steam turbines. Single-piece weights from 500 kg to 30 tonnes in 1.4913 are routinely produced.
Valve Spindles & Bodies
Main steam stop valves, control valves, and bypass valves requiring resistance to steam erosion and creep deformation under sustained high-temperature cycling.
High-Temperature Bolting
Flange bolts, studs, and nuts for steam chests, valve bonnets, and turbine casings that must maintain clamping force under sustained temperature without stress relaxation.
Steam Chests & Casings
Turbine inner casings and steam-side covers where dimensional stability under cyclic thermal loading and long-term creep resistance are simultaneously required.
Boiler Pressure Nozzles
High-pressure boiler drum nozzles and main steam connection forgings in ultra-supercritical (USC) thermal power units operating at 600°C+ conditions.
Frequently Asked Questions About 19CrMoVNbN11-1 Steel
Contact Jiangsu Liangyi Co., Limited
For technical enquiries, custom forging quotations, or material specification questions regarding 19CrMoVNbN11-1 (1.4913) and other high-temperature steel forgings, contact our team directly:
Jiangyin City, Jiangsu Province,
China
Source Certified 19CrMoVNbN11-1 Forgings
Jiangsu Liangyi Co., Limited is an ISO 9001:2015 certified open die forging manufacturer, established in 1997 in Jiangyin, China, with 25+ years of experience supplying 1.4913 components to power generation, oil & gas, and pressure vessel industries across 50+ countries. Components from 30 kg to 30 tonnes. Full EN 10204 3.1/3.2 mill test certificates are supplied with every delivery.