Si vous recherchez un matériau qui résiste à la fois à la corrosion acide et à la croissance bactérienne, idéal pour les produits chimiques, nourriture, or pharmaceutical use—UNS N08020 (Menuisier 20 Équivalent) est un premier choix. Cet alliage nickel-chrome-molybdène est réputé pour sa polyvalence dans les environnements difficiles, correspondant à la performance de Carpenter 20. Ce guide détaille ses principales propriétés, utilisations réelles, méthodes de fabrication, et comment il se compare à d'autres matériaux, afin que vous puissiez prendre des décisions éclairées pour vos projets.
1. Material Properties of UNS N08020 Carpenter 20 Équivalent
The strength of UNS N08020 lies in its balanced composition and well-rounded characteristics. Let’s explore each property clearly.
1.1 Composition chimique
Every element works together to boost corrosion resistance and durability. Below is its typical composition (by weight):
| Élément | Gamme de contenu (%) | Key Role |
|---|---|---|
| Nickel (Dans) | 32–38 | Base metal—provides ductility and protects against stress cracking |
| Chrome (Cr) | 19–21 | Enhances oxidation resistance and fights pitting in acidic liquids |
| Molybdène (Mo) | 2.0–3,0 | Boosts resistance to strong acids (like sulfuric and phosphoric acid) |
| Fer (Fe) | Balance | Adds structural strength and reduces material cost |
| Carbone (C) | Max 0.07 | Minimizes carbide formation (prevents intergranular corrosion) |
| Manganèse (Mn) | Max 2.0 | Aids in manufacturing (par ex., welding and casting) |
| Silicium (Et) | Max 1.0 | Reduces oxidation at high temperatures |
| Soufre (S) | Max 0.03 | Kept low to prevent brittleness and corrosion in harsh environments |
| Cuivre (Cu) | 3.0–4.0 | Improves resistance to sulfuric acid and prevents bacterial growth |
| Niobium (Nb) | 0.1–0,3 | Stabilizes the alloy and enhances high-temperature strength |
| Titane (De) | 0.1–0,3 | Works with niobium to prevent intergranular corrosion |
1.2 Propriétés physiques
These traits make UNS N08020 easy to design with for industrial tasks:
- Densité: 8.0 g/cm³ (lighter than Hastelloy alloys, similar to stainless steel)
- Point de fusion: 1350–1400°C (2460–2550°F) – handles high-heat processes like welding
- Conductivité thermique: 15.0 Avec(m·K) at 20°C (68°F); increases to 22.0 Avec(m·K) at 600°C – efficient heat transfer
- Thermal Expansion Coefficient: 16.0 μm/(m·K) (20–100°C); 18.5 μm/(m·K) (20–600°C) – minimal warping when heated
- Electrical Resistivity: 110 Ω·mm²/m at 20°C – suitable for electrical components in corrosive areas
- Propriétés magnétiques: Non-magnetic – ideal for medical or electronic equipment where magnetism is a problem
1.3 Propriétés mécaniques
UNS N08020 balances strength and flexibility, même dans des conditions difficiles. All values below are for the annealed (traité thermiquement) version:
| Propriété | Valeur (Room Temperature) |
|---|---|
| Résistance à la traction | Min 550 MPa (80 ksi) |
| Limite d'élasticité | Min 240 MPa (35 ksi) |
| Élongation | Min 35% (dans 50 mm) |
| Dureté | Max 180 HB (Brinell) |
| Résistance à la fatigue | 220 MPa (10⁷ cycles) |
| Résistance au fluage | Maintains strength up to 700°C (1290°F) |
1.4 Autres propriétés
- Résistance à la corrosion: Excellent in sulfuric acid (even at high concentrations) and acidic brines – outperforms stainless steel and Monel 400.
- Oxidation Resistance: Resists scaling in air up to 900°C (1650°F) for short periods – ideal for furnace components.
- Stress Corrosion Cracking (SCC) Resistance: Resists SCC in chloride-rich solutions (a common issue for 316 acier inoxydable).
- Pitting Resistance: High resistance to pitting in salty or acidic liquids (suitable for marine and chemical applications).
- Hot/Cold Working Properties: Easy to hot forge (at 1100–1200°C) and cold form (par ex., flexion, estampillage) – retains strength after shaping.
2. Applications of UNS N08020 Carpenter 20 Équivalent
UNS N08020’s mix of corrosion resistance and bacterial protection makes it perfect for demanding industries. Voici ses utilisations les plus courantes, avec des exemples concrets:
2.1 Chemical Processing Equipment
- Use Case: A chemical plant in India uses UNS N08020 for sulfuric acid storage tanks. The tanks have lasted 8 years with no corrosion—compared to 3 years for stainless steel tanks.
- Other Uses: Acid mixers, échangeurs de chaleur, and pipework for strong acids.
2.2 Food Processing Equipment
- Use Case: A dairy factory in the Netherlands uses UNS N08020 for milk pasteurization tanks. The alloy’s copper content prevents bacterial growth (like E. coli), meeting strict food safety standards.
2.3 Pharmaceuticals
- Use Case: A pharmaceutical company in the U.S. uses UNS N08020 for drug mixing tanks. The alloy is non-toxic (meets FDA rules) and resists corrosion from acidic drugs.
2.4 Marine Applications
- Use Case: A shipyard in South Korea uses UNS N08020 for seawater cooling systems. The system has run for 10 years without pitting—stainless steel systems failed after 4 années.
2.5 Échangeurs de chaleur
- Use Case: A power plant in Germany uses UNS N08020 for heat exchanger tubes. The tubes handle acidic coolant—they’ve lasted 7 années, par rapport à 4 years for carbon steel tubes.
3. Manufacturing Techniques for UNS N08020 Carpenter 20 Équivalent
To maximize UNS N08020’s performance, manufacturers use these specialized methods:
- Fonderie: Investment casting (using a wax mold) is ideal for complex shapes (par ex., corps de vannes). The low sulfur content prevents defects during casting.
- Forgeage: Hot forging (at 1100–1200°C) shapes the alloy into strong parts like pump impellers. Cold forging (à température ambiante) is used for small components (par ex., boulons) to boost hardness.
- Soudage: Gas Tungsten Arc Welding (GTAW) is recommended. Use matching filler metals (par ex., ERNiCrMo-3) to maintain corrosion resistance. Pre-weld cleaning (to remove oils) is critical for strong welds.
- Usinage: Utiliser des outils en carbure (they stay sharp longer). Add coolant (par ex., mineral oil) to prevent overheating—UNS N08020 can work-harden if cut too quickly.
- Traitement thermique:
- Recuit: Heat to 980–1050°C, cool rapidly (air or water) – softens the alloy for forming and restores ductility.
- Stress Relieving: Heat to 700–800°C, cool slowly – reduces internal stresses after welding or cold working.
- Traitement de surface: Passivation (using nitric acid) enhances pitting resistance. No painting is needed— the alloy’s natural surface resists rust in most environments.
4. Étude de cas: UNS N08020 in a Sulfuric Acid Reactor
A chemical company in Brazil needed a reactor to produce fertilizers. The reactor uses 93% sulfuric acid at 150°C—their old reactor (316 acier inoxydable) failed after 2 years due to corrosion.
They switched to a UNS N08020 reactor. Here’s the result:
- Lifespan: The reactor has run for 6 years with no corrosion.
- Économies de coûts: Les coûts de maintenance ont diminué 60% (no need for frequent part replacements).
- Performance: The alloy’s even heat transfer improved fertilizer production efficiency by 12%.
This case proves why UNS N08020 is the top choice for sulfuric acid processes.
5. Comparative with Other Materials
How does UNS N08020 Carpenter 20 Equivalent stack up against other common materials? The table below compares key properties:
| Matériel | Résistance à la corrosion (Sulfuric Acid) | Résistance à la traction (MPa) | Max Service Temp (°C) | Coût (Relative) |
|---|---|---|---|---|
| UNS N08020 | Excellent | 550 | 700 | Moyen-élevé |
| Acier inoxydable 316 | Pauvre | 515 | 870 | Faible |
| Titanium Alloy Ti-6Al-4V | Bien (dilute acids) | 860 | 400 | Très élevé |
| Inconel 625 | Excellent (high temps) | 930 | 980 | Haut |
| Hastelloy C22 | Excellent (mixed acids) | 690 | 650 | Haut |
| Monel 400 | Bien (seawater) | 550 | 480 | Moyen |
| Acier au carbone | Very Poor | 400 | 425 | Très faible |
Key Takeaways:
- UNS N08020 outperforms stainless steel and carbon steel in sulfuric acid corrosion resistance.
- It’s more affordable than titanium alloys and Inconel, making it a cost-effective choice for chemical tasks.
- Inconel 625 works better at extreme temps, but UNS N08020 offers better value for sulfuric acid applications.
Yigu Technology’s Perspective
Chez Yigu Technologie, we recommend UNS N08020 (Menuisier 20 Équivalent) for clients in chemical, nourriture, and pharmaceutical industries. Its excellent sulfuric acid resistance and bacterial protection make it a reliable, long-lasting solution. Our team provides custom machining and heat treatment for UNS N08020 components, ensuring they meet strict industry standards. For projects needing a balance of corrosion resistance and safety, UNS N08020 delivers unmatched value.
FAQ
1. Is UNS N08020 (Menuisier 20 Équivalent) suitable for food processing?
Oui! Its copper content prevents bacterial growth, and it’s non-toxic (répond aux normes FDA). It’s ideal for tanks, convoyeurs, and mixers that handle acidic or high-moisture food products.
2. Can UNS N08020 handle concentrated sulfuric acid?
Absolument. It resists 93% concentrated sulfuric acid even at high temperatures (jusqu'à 150°C)—way better than stainless steel, which corrodes quickly in strong sulfuric acid.
3. What’s the typical lifespan of UNS N08020 parts in chemical processing?
In harsh sulfuric acid environments, UNS N08020 parts last 6–10 years—2–3 times longer than stainless steel parts. Proper maintenance (par ex., recuit) can extend this lifespan even further.