What is 1.4558 (X2NiCrAlTi32-20) Steel?
Main characteristics: Good corrosion resistance to SCC, pitting, and crevice corrosion; high-temperature oxidation resistance up to 1000°C; cryogenic toughness down to −196°C; excellent weldability; nuclear and offshore grade qualification.
Main applications: Nuclear power, oil & gas, LNG cryogenic, petrochemical, turbomachinery, and industrial valve industries.
Production Standards & Compliance
All Jiangsu Liangyi 1.4558 (X2NiCrAlTi32-20) forgings comply with the following international standards:
- EN 10216-5:2014 — EU standard for seamless stainless steel pressure tubes
- EN 10297-2:2005 — EU standard for seamless round stainless steel tubes for mechanical and general engineering
- EN 10088-1:2005 — EU standard for stainless steels, includes 1.4558 grade
- API 6A — Global oil and gas standard for wellhead and Christmas tree equipment
- NORSOK M122 / M123 — Offshore oil and gas material standards (North Sea)
- ASTM B409 / ASTM B564 / ASME BPVC — North American standards, equivalent to UNS N08811
Chemical Composition
Strictly controlled per EN 10088-1 to ensure consistent corrosion resistance, high-temperature stability, and cryogenic toughness across all production heats.
| Element | EN Standard Range |
|---|---|
| Carbon (C) | Max 0.03% |
| Silicon (Si) | Max 0.7% |
| Manganese (Mn) | Max 1.0% |
| Nickel (Ni) | 32.0% – 35.0% |
| Phosphorus (P) | Max 0.020% |
| Sulfur (S) | Max 0.015% |
| Chromium (Cr) | 20.0% – 23.0% |
| Titanium (Ti) | Max 0.60% |
| Aluminum (Al) | 0.15% – 0.45% |
| Iron (Fe) | Balance |
Mechanical Properties
Stable mechanical properties after standard +AT (Solution Annealed & Treated) heat treatment per EN standards. The low-temperature impact toughness at −196°C makes this alloy suitable for LNG and cryogenic applications.
| Property | Test Condition | EN Standard Value |
|---|---|---|
| Tensile Strength (Rm) | +AT | 450 – 700 MPa |
| 0.2% Proof Strength (Rp0.2) | +AT | Min 180 MPa |
| Longitudinal Impact Energy (KV) | +20°C | Min 120 J |
| Transverse Impact Energy (KV) | +20°C | Min 90 J |
| Transverse Impact Energy (KV) | −196°C | Min 60 J |
| Longitudinal Elongation (A) | +AT | Min 35% |
| Transverse Elongation (A) | +AT | Min 30% |
| Hardness (HB) | +AT | Typically 130–180 HB |
International Material Equivalents
| Standard System | Grade Name | Main Standards |
|---|---|---|
| European EN | 1.4558, X2NiCrAlTi32-20 | EN 10088-1, EN 10216-5 |
| German DIN | X2NiCrAlTi32-20 | DIN 17400 |
| ASTM/UNS | UNS N08811 (Alloy 800HT) | ASTM B409, ASTM B564 |
| ASME Code | Alloy 800HT equivalent | ASME BPVC Section II Part B |
| NORSOK (Oil & Gas) | Per NORSOK M122/M123 | NORSOK M122, NORSOK M123 |
Physical Properties
| Property | Value | Test Temperature |
|---|---|---|
| Density (ρ) | 7.95 g/cm³ | 20°C |
| Melting Range | 1350–1400°C | — |
| Thermal Conductivity (λ) | 11.5 W/(m·K) | 20°C |
| Thermal Conductivity (λ) | 18.5 W/(m·K) | 500°C |
| Thermal Expansion Coefficient (α) | 15.0 × 10⁻⁶/K | 20–100°C |
| Thermal Expansion Coefficient (α) | 16.5 × 10⁻⁶/K | 20–500°C |
| Specific Heat Capacity (c) | 460 J/(kg·K) | 20°C |
| Electrical Resistivity (ρ) | 1.03 × 10⁻⁶ Ω·m | 20°C |
| Elastic Modulus (E) | 195 GPa | 20°C |
| Elastic Modulus (E) | 170 GPa | 500°C |
Corrosion Resistance
The outstanding corrosion resistance of 1.4558 (X2NiCrAlTi32-20) comes from its high nickel (32–35%) and chromium (20–23%) content combined with ultra-low carbon (max 0.03%) and aluminum-titanium stabilization:
- General Corrosion: High nickel content provides resistance to hydrochloric, phosphoric, and sulfuric acids over a wide range of concentrations and temperatures.
- Stress Corrosion Cracking (SCC): Austenitic stainless steel with nickel content over 30% becomes highly resistant to chloride-induced SCC — essential for offshore oil & gas and marine applications.
- Pitting & Crevice Corrosion: The Ni + Cr combination provides a high PREN (Pitting Resistance Equivalent Number), suitable for seawater and aggressive chloride media.
- High-Temperature Oxidation: Aluminum forms a stable Al₂O₃ protective scale, resisting sulfidation and oxidation up to 1000°C in cyclic thermal service.
- Sensitization Prevention: Ultra-low carbon (C ≤ 0.03%) and titanium-aluminum stabilization prevent intergranular corrosion (IGC) and heat-affected zone sensitization.
- Sour Service (H₂S): 1.4558 meets NACE MR0175/ISO 15156 for sour oil and gas environments with H₂S levels above 300 ppm.
Weldability
1.4558 (X2NiCrAlTi32-20) has good weldability due to its ultra-low carbon content, which minimizes carbide precipitation at grain boundaries during the welding thermal cycle.
- Preheating: Not required for sections under 25 mm. For thicker sections, preheating to 100–150°C reduces hydrogen-induced cracking risk.
- Post-Weld Heat Treatment (PWHT): Generally not required for corrosion service. Solution annealing (+AT at 1050–1100°C) may be required for nuclear pressure vessels and certain critical applications.
- Filler Metal: AWS A5.11 ENiCrFe-2 or ENiCrMo-6 electrodes; AWS A5.14 ERNiCrMo-3 (Alloy 625) wire for GMAW or GTAW. Minimum 55% nickel content required.
- Welding Processes: GTAW (TIG), GMAW (MIG), SMAW, SAW, and FCAW all applicable. GTAW with argon back-purging recommended for root passes.
- Interpass Temperature: Maximum 150°C.
- NDT After Welding: PT or RT per EN ISO 17635 or ASME Section V. Procedure qualification per ISO 15614-1 (WPQR) or ASME Section IX.
Heat Treatment
Standard heat treatment: +AT (Solution Annealed & Treated) per EN 10216-5 and EN 10088-3.
| Treatment | Temperature Range | Cooling | Purpose |
|---|---|---|---|
| Solution Annealing (+AT) | 1050°C – 1100°C | Water quench or rapid air cool | Dissolve carbides, homogenize microstructure, restore corrosion resistance |
| Stress Relief (optional) | 870°C – 950°C | Furnace cool to 600°C, then air cool | Reduce residual stresses in complex weldments without sensitizing |
| Stabilization Anneal (optional) | 900°C – 925°C | Air cool | Precipitate Ti/Al carbides, prevent HAZ sensitization in welded assemblies |
1.4558 vs Similar Alloy Grades
| Property | 1.4558 (X2NiCrAlTi32-20) | 1.4876 (Alloy 800H) | 316L (1.4404) | 904L (1.4539) |
|---|---|---|---|---|
| Ni Content | 32–35% | 30–35% | 10–14% | 23–28% |
| Cr Content | 20–23% | 19–23% | 16–18% | 19–23% |
| Max Carbon (C) | 0.03% | 0.10% | 0.03% | 0.02% |
| Max Service Temp | 1000°C | 1050°C | 870°C | 400°C |
| Cryogenic (min) | −196°C | −100°C | −196°C | −196°C |
| SCC Resistance | Excellent | Very Good | Limited | Excellent |
| Nuclear Grade | Yes | Yes | No | No |
| NORSOK Qualified | Yes (M122/M123) | Limited | Partial | Partial |
Full-Process Production & Machining Capabilities
Forging & Heat Treatment Equipment
- 2000T / 4000T / 6300T hydraulic forging presses; 0.75T–9T electro-hydraulic forging hammers; manipulators with 60T lifting capacity
- 1M & 5M seamless ring rolling machines for custom diameter rolled rings
- 30T EAF, LF, VOD steel melting equipment for full chemical composition control
- Heating forging furnaces (max 150T capacity); hydrogen bake-out furnaces up to 14M length
- Semi-automatic heat treatment system with furnaces up to 18M length and quenching tanks up to 16M depth
Precision Machining & Quality Inspection
Complete rough and finish machining through vertical lathes, parallel lathes, extra-large parallel lathes, CNC boring machines, milling machines, planning machines, and column drills. All 1.4558 forgings undergo: chemical composition testing (OES), mechanical property testing (tensile, impact, hardness), non-destructive testing (UT, PT, MT), metallographic inspection, and dimensional inspection.
Uses & Global Applications
⚙️ Oil & Gas / Offshore
API 6A wellhead components: casing heads, tubing heads, tubing spools, hangers, flanges, studded crosses, connectors, and flexible joints. NORSOK M122/M123 compliant.
❄️ LNG Cryogenic
Cryogenic butterfly and gate valve bodies, stems, and bonnets operating at −196°C. Meets EN 12516 and BS 6364 cryogenic valve standards. Minimum 60 J Charpy at −196°C.
⚛️ Nuclear Power
Reactor coolant pump rotors, impellers, casings, containment seal chambers, and butterfly valve main shafts for Nuclear Safety Class 1 applications (AP1000 PWR).
🔧 Industrial Valves
Ball valve bodies, bonnets, valve bodies, stems, closures, seat rings, valve cores, and discs for cryogenic butterfly valves (HPBV) and sour service environments.
💨 Turbomachinery
Centrifugal compressor impellers, shrouded impellers, gas compressor turbine blades, and main shafts for industrial turbines across Asia and Europe.
🏭 Pressure Vessels & Heat Exchangers
Pump casings, reactor nozzles, tube sheets, shells, channel flanges, baffle plates, and nozzles for global petrochemical and power generation projects.
Case Studies
LNG Terminal Project — Europe | 2024
Custom X2NiCrAlTi32-20 forged valve bodies for LNG cryogenic terminal. Full EN 10204 3.2 documentation. Performance at −196°C confirmed on-spec by third-party inspection.
LNG Cryogenic · European ClientOffshore Oil & Gas Project — Gulf of Mexico | 2024
1.4558 seamless rolled rings for offshore wellhead API 6A system. Full DNV-GL 3.2 certification. Delivered FOB Shanghai within agreed schedule. Long-term supply cooperation.
API 6A · Gulf of MexicoNuclear Power Plant Project — Asia-Pacific | 2024
Reactor coolant pump casings and impellers for AP1000 pressurized water reactor plants in China and Southeast Asia. Nuclear Safety Class 1 requirements. Third-party witnessed inspection.
Nuclear Safety Class 1 · Asia-PacificQuality Certifications & Full Traceable Material
Jiangsu Liangyi holds ISO 9001:2015 and API 6A certification. Our facility operates an in-house ISO/IEC 17025-compliant metallurgical laboratory. All 1.4558 forged parts are shipped with EN 10204 3.1 or 3.2 material test reports.
EN 10204 3.2 countersignature is available through internationally recognized third-party inspection organizations: DNV-GL, Bureau Veritas, Lloyd's Register, ABS, RINA, and TÜV. This ensures full material traceability from raw steel heat number to final part.
1.4558 Forging Price & Free Quote
How to Order — 6 Steps
Send Inquiry with Drawings or Specifications
Email to sales@jnmtforgedparts.com or WhatsApp +86-13585067993. Include material spec 1.4558 / X2NiCrAlTi32-20, order quantity, and inspection requirements.
Receive Free Quotation Within 24 Hours
Detailed quotation including unit price, heat treatment, testing scope, and certification options (EN 10204 3.1 or 3.2).
Order Confirmation
Formal purchase order covering product specifications, certification type (3.1 or 3.2), delivery terms (FOB, CIF, EXW), and inspection standards (EN, ASTM).
Full-Process Production with Witnessing Option
Steel melting (EAF/LF/VOD) → open die forging or ring rolling → heat treatment (+AT) → rough machining → NDT → finish machining → final inspection. Third-party inspectors may witness any stage.
Third-Party Inspection & EN 10204 Certification
EN 10204 3.1 or 3.2 material test reports prepared and countersigned by DNV-GL, Bureau Veritas, Lloyd's Register, ABS, RINA, or TÜV.
Shipment with Full Documentation
Wooden case packaging for sea freight. Full document set: commercial invoice, packing list, certificate of origin, bill of lading, material certificates.