Si trabajas en industrias como la automotriz., aeroespacial, o maquinaria pesada, Necesitas acero que equilibre un duro, wear-resistant surface with a tough core.EN 18NiCrMo14-6 case hardening steel—a European-standard alloy rich in nickel, cromo, y molibdeno, ofrece exactamente eso. Esta guía desglosa sus propiedades clave., aplicaciones del mundo real, proceso de fabricación, y cómo se compara con otros materiales, helping you choose the right steel for high-stress, wear-prone parts.
1. Material Properties of EN 18NiCrMo14-6 Case Hardening Steel
EN 18NiCrMo14-6’s unique alloy composition (especially high nickel and molybdenum) makes it ideal for case hardening. Let’s explore its properties in detail.
1.1 Composición química
EN 18NiCrMo14-6 follows strict European standards (EN 10084), ensuring consistent performance for case hardening. Below is its typical chemical makeup:
| Element | Symbol | Content Range (%) | Key Role |
|---|---|---|---|
| Carbon (do) | do | 0.15 – 0.21 | Low enough for ductile core; reacts with carburizing to form hard surface |
| Níquel (En) | En | 3.00 – 3.50 | Boosts core toughness and fatigue resistance |
| Chromium (cr) | cr | 1.40 – 1.70 | Improves hardenability and surface wear resistance |
| Molibdeno (Mes) | Mes | 0.45 – 0.55 | Enhances high-temperature strength and prevents temper brittleness |
| Manganese (Mn) | Mn | 0.50 – 0.80 | Increases workability and tensile strength |
| Silicio (Y) | Y | 0.15 – 0.35 | Aids deoxidation during steelmaking |
| Sulfur (S) | S | ≤ 0.035 | Controlled to avoid brittleness |
| Phosphorus (PAG) | PAG | ≤ 0.035 | Minimized to prevent cracking |
| Cobre (Cu) | Cu | ≤ 0.30 | Trace element with no major performance impact |
1.2 Physical Properties
These properties describe how EN 18NiCrMo14-6 behaves under physical conditions like temperature and magnetism:
- Densidad: 7.85 gramos/cm³ (same as most nickel-chromium-molybdenum steels)
- Punto de fusión: 1,420 – 1,460 °C (2,588 – 2,660 °F)
- Conductividad térmica: 44.0 W/(m·K) en 20 °C (room temperature)
- Coeficiente de expansión térmica: 11.8 × 10⁻⁶/°C (de 20 – 100 °C)
- Propiedades magnéticas: Ferromagnetic (attracts magnets), useful for sorting and non-destructive testing.
1.3 Propiedades mecánicas
Mechanical properties of EN 18NiCrMo14-6 depend on case hardening (carburación + temple + templado). Below are typical values for thesuperficie (case) ycentro:
| Propiedad | Measurement Method | Surface (Caso) Valor | Core Value |
|---|---|---|---|
| Dureza (Rockwell) | CDH | 58 – 62 CDH | 30 – 35 CDH |
| Dureza (Vickers) | HV | 550 – 600 HV | 280 – 320 HV |
| Resistencia a la tracción | MPa | — | ≥ 900 MPa |
| Yield Strength | MPa | — | ≥ 650 MPa |
| Alargamiento | % (en 50 milímetros) | — | ≥ 15% |
| Impact Toughness | J (en 20 °C) | — | ≥ 60 J |
| Fatigue Limit | MPa (rotating beam) | — | ≥ 450 MPa |
1.4 Other Properties
EN 18NiCrMo14-6’s standout properties make it perfect for case-hardened parts:
- Case Hardening Depth: Típicamente 0.8 – 2.0 milímetros (adjustable via carburizing time/temperature) — enough for wear-prone surfaces like gear teeth.
- Resistencia al desgaste: Hard surface (from carburizing) resists abrasion, while the tough core absorbs impact.
- Fatigue Resistance: Nickel and molybdenum improve resistance to repeated loads—critical for gears and shafts.
- Hardenability: Excellent—can be case-hardened evenly across large or complex parts (p.ej., ejes).
- Resistencia a la corrosión: Moderado (better than standard carbon steels); needs coatings (like zinc plating) for wet/harsh environments.
- Core Hardness: Balanced toughness (30 – 35 CDH) prevents parts from breaking under impact.
2. Applications of EN 18NiCrMo14-6 Case Hardening Steel
EN 18NiCrMo14-6’s hard surface and tough core make it ideal for parts that face both wear and impact. Here are its key uses:
- Engranajes: El #1 application—including automotive transmission gears, industrial gearbox gears, and aerospace engine gears (where wear and torque meet).
- Ejes: Drive shafts in trucks, maquinaria industrial, and turbines (needing a hard outer layer to resist wear and a tough core to handle torque).
- Ejes: Automotive axles (especially heavy-duty trucks) and agricultural machinery axles—absorbing impact while resisting wear.
- Pinions: Small gears in gearboxes or steering systems (relying on precise case hardening for smooth operation).
- Componentes automotrices: Clutch hubs, árboles de levas, and differential parts—high-stress parts needing wear resistance.
- Maquinaria Industrial: Conveyor drive gears, ejes de bomba, and compressor components—operating under long hours and heavy loads.
- Componentes aeroespaciales: Landing gear shafts and engine accessory gears (where reliability and weight balance matter).
- Agricultural Machinery: Tractor gearboxes and harvester shafts—handling dusty, high-impact conditions.
- Mining Equipment: Crusher gears and conveyor shafts—resisting abrasion from rocks and heavy loads.
3. Manufacturing Techniques for EN 18NiCrMo14-6
Producing EN 18NiCrMo14-6 requires precise steps to achieve the perfect case-hardened finish. Here’s the typical process:
- Steelmaking:
- Most EN 18NiCrMo14-6 is made using an Electric Arc Furnace (EAF) with vacuum degassing. This removes impurities and ensures precise control of alloy elements (especially nickel and molybdenum) to meet EN 10084 estándares.
- Laminación:
- After steelmaking, the metal is Hot Rolled (en 1,150 – 1,250 °C) into billets, verja, or sheets. For precision parts, it’s then Cold Rolled (room temperature) to improve surface finish and dimensional accuracy.
- Precision Forging:
- Partes complejas (like gears or shafts) are forged into near-final shapes at high temperatures. This refines the grain structure, enhancing core toughness—critical for high-stress applications.
- Mecanizado (Pre-Carburizing):
- Forged parts are machined to near-final dimensions using Torneado (for cylindrical shapes like shafts) o Molienda (for gears). A small tolerance (0.1 – 0.2 milímetros) is left for post-heat treatment grinding.
- Tratamiento térmico (Case Hardening):
- The most critical step—creating a hard surface and tough core:
- Carburación: Heat the part to 880 – 930 °C in a carbon-rich atmosphere (natural gas or propane) para 4 – 12 horas. Carbon diffuses into the surface (0.8 – 2.0 mm de profundidad) to raise carbon content to 0.8 – 1.0%.
- Temple: Rapidly cool the part in oil or high-pressure gas to harden the carbon-rich surface.
- Tempering: Reheat to 180 – 220 °C to reduce brittleness while maintaining surface hardness.
- The most critical step—creating a hard surface and tough core:
- Mecanizado (Post-Carburizing):
- Parts are Ground to final dimensions (removing the small pre-carburizing tolerance). This ensures ultra-smooth surfaces (critical for gear teeth) y tolerancias estrictas (±0,005 mm).
- Tratamiento superficial:
- Optional steps to enhance performance:
- Nitriding: Adds a thin, extra-hard layer (if even higher wear resistance is needed).
- Blackening: Forms a protective oxide layer to prevent minor rust.
- Revestimiento: Zinc plating or powder coating for corrosion resistance in wet environments.
- Optional steps to enhance performance:
- Control de calidad:
- Rigorous testing ensures quality:
- Chemical analysis: Verify alloy content via spectrometry.
- Case hardening depth test: Measure surface carbon penetration (using microhardness testing).
- Hardness testing: Check surface (CDH) and core (CDH) dureza.
- Non-destructive testing: Ultrasonic testing for internal cracks; magnetic particle testing for surface defects.
- Dimensional inspection: Use CMMs (Máquinas de medición de coordenadas) para comprobar las tolerancias.
- Rigorous testing ensures quality:
4. Estudios de caso: EN 18NiCrMo14-6 in Action
Real-world examples show how EN 18NiCrMo14-6 solves industry challenges.
Estudio de caso 1: Automotive Gear Failure Analysis
A heavy-duty truck manufacturer faced frequent gear failures in their transmission (lasting only 150,000 km). The original gears used a low-nickel case hardening steel, which had a brittle core and uneven case depth. Switching to EN 18NiCrMo14-6 gears (with controlled carburizing to 1.2 mm case depth) extended gear life to 400,000 km. This reduced warranty claims by 80% y salvado $500,000 anualmente.
Estudio de caso 2: Mining Equipment Pinion Optimization
A mining company struggled with pinion failures in their crusher (cada 3 meses) due to abrasion and impact. They replaced the existing steel with EN 18NiCrMo14-6 pinions, paired with nitriding surface treatment. Post-switch, pinion life increased to 12 meses, reducir el tiempo de inactividad por mantenimiento 75% and replacement costs by 60%.
5. EN 18NiCrMo14-6 vs. Other Materials
How does EN 18NiCrMo14-6 compare to other case hardening steels and materials? The table below breaks it down:
| Material | Similarities to EN 18NiCrMo14-6 | Diferencias clave | Mejor para |
|---|---|---|---|
| AISI 52100 | Grado de rodamiento; ferromagnetic | No nickel; not case-hardened (through-hardened); brittle core | Standard bearings (not gears/shafts) |
| JIS SUJ2 | Carbon-chromium alloy; resistente al desgaste | No nickel; through-hardened; lower toughness | Japanese automotive bearings |
| GCr15 | Grado de rodamiento; carbon-chromium | No nickel; through-hardened; poor impact resistance | Chinese industrial bearings |
| 100Cr6 | European standard; through-hardened | No nickel; brittle core; not for case hardening | Light-duty bearings |
| EN 100CrMo7 | Chromium-molybdenum alloy; resistente al desgaste | Low nickel; through-hardened; lower core toughness | Heavy-duty bearings (not gears) |
| AISI M50 | High-temperature strength | No nickel; through-hardened; for high-speed bearings | Aerospace turbine bearings |
| Acero inoxidable (AISI 416) | Resistente a la corrosión | Lower surface hardness; more expensive; weaker core | Food processing gears (wet environments) |
| Ceramic Components (Al₂O₃) | Resistente al desgaste | Frágil (no impact resistance); very expensive | Alta precisión, low-impact parts (not gears) |
| Componentes de plástico (PA66) | Resistente a la corrosión | Low strength; no high-load use | Light-duty, low-speed parts (p.ej., engranajes de juguete) |
Yigu Technology’s Perspective on EN 18NiCrMo14-6
En Yigu Tecnología, EN 18NiCrMo14-6 is our top choice for clients needing case-hardened parts like gears and shafts. Its nickel-molybdenum blend delivers the perfect balance of surface wear resistance and core toughness—critical for heavy automotive and mining applications. We use precise carburizing (controlling depth to ±0.1 mm) and post-heat treatment grinding to ensure parts meet tight tolerances. For clients in harsh environments, we add nitriding or zinc plating, making EN 18NiCrMo14-6 parts last 2–3x longer than standard case hardening steels.
FAQ About EN 18NiCrMo14-6 Case Hardening Steel
- What is the ideal case hardening depth for EN 18NiCrMo14-6?
It depends on the application: 0.8 – 1.2 mm for gears (balanced wear and flexibility), 1.5 – 2.0 mm for shafts/axles (higher wear resistance), and can be adjusted via carburizing time and temperature. - Can EN 18NiCrMo14-6 be used in corrosive environments?
It has moderate corrosion resistance. For wet or chemical-rich environments (p.ej., marine or food processing), apply zinc plating or powder coating to prevent rust and extend service life. - How does EN 18NiCrMo14-6 differ from through-hardened steels like AISI 52100?
EN 18NiCrMo14-6 is case-hardened (hard surface, tough core) for wear + resistencia al impacto, making it ideal for gears/shafts. AISI 52100 is through-hardened (uniformly hard, brittle core), better suited for bearings that don’t face heavy impact.