Cobalt Alloys HY ST31 / Stellite 31 / UNS R30031 Product Introduction
Cobalt alloys such as HY ST31 (Stellite 31) and UNS R30031 are renowned for their exceptional resistance to wear, corrosion, and high temperatures. This article provides a comprehensive introduction to these alloys, covering their chemical composition, mechanical properties, performance at different temperatures, industry applications, shapes and sizes, production standards, welding and processing capabilities, advantages and disadvantages, and comparisons with similar alloys.
Composition chimique
HY ST31 (Stellite 31) and UNS R30031 have a complex chemical composition designed to achieve their high-performance properties:
| Élément | Composition (%) |
|---|---|
| Cobalt (Co) | 30,0 – 34,0 |
| Chrome (Cr) | 27.0 – 31.0 |
| Tungstène (W) | 12.0 – 15.0 |
| Nickel (Ni) | 3,0 – 5,0 |
| Fer (Fe) | 3.0 – 4.5 |
| Molybdène (Mo) | 2.0 – 3.5 |
| Carbone (C) | 00,05 – 0,15 |
| Manganèse (Mn) | 1,0 maximum |
| Silicium (Si) | 1,0 maximum |
| Phosphore (P) | 00,04 maximum |
| Soufre (S) | 00,04 maximum |
Propriétés mécaniques
HY ST31 (Stellite 31) and UNS R30031 exhibit excellent mechanical properties suitable for high-stress applications:
| Propriété | Valeur |
|---|---|
| Résistance à la traction, ksi (MPa) | 135 (930) min |
| Limite d'élasticité (compensation de 0,2 %), ksi (MPa) | 105 (725) min |
| Allongement (% en 2 pouces) | 20 min |
| Dureté, Rockwell C (HRC) | 38 – 44 |
Caractéristiques de performance
These cobalt alloys offer outstanding performance in severe environments:
- Résistance à l'usure : Exceptional resistance to abrasion, erosion, and metal-to-metal wear, making them ideal for high-stress wear applications.
- Résistance à la corrosion : Excellent resistance to oxidation and corrosion in high-temperature and corrosive environments, including acids and alkalis.
- Résistance à haute température : Maintains strength and hardness at elevated temperatures, up to approximately 1200°F (650°C).
Applications industrielles
HY ST31 (Stellite 31) and UNS R30031 are utilized across various industries where durability and resistance to wear and corrosion are critical:
| Secteur industriel | Applications |
|---|---|
| Aérospatial | Turbine blades, combustion chambers, and high-temperature engine components. |
| Pétrole et Gaz | Valves, pump components, and drilling equipment exposed to abrasive and corrosive fluids. |
| Medical | Surgical instruments, prosthetic devices, and biomedical implants requiring wear and corrosion resistance. |
Formes et tailles
These alloys are available in various forms and sizes to suit different applications:
- Formes: Feuilles, plaques, barres, tubes et formes personnalisées.
- Tailles : Épaisseur allant de 0,025 pouces à 1,000 pouces (0,64 mm à 25,4 mm), diamètre allant de 0,25 pouces à 6,0 pouces (6,35 mm à 152,4 mm).
Normes de production
HY ST31 (Stellite 31) and UNS R30031 conform to industry standards ensuring quality and reliability:
| Formulaire de produit | Formes disponibles | Tailles disponibles | Normes de production |
|---|---|---|---|
| Barres/tiges | Barres rondes, barres carrées | Diamètre : 0,25″ – 6,0″ (6,35 mm – 152,4 mm) | ASTM A732, AMS 5759 |
| Plaques/Feuilles | Plaques, Feuilles | Épaisseur : 0,025″ – 1,000″ (0,64 mm – 25,4 mm) | ASTM A732, AMS 5537 |
| Fils | Fils | Diamètre : 0,010″ – 0,250″ (0,25 mm – 6,35 mm) | ASTM A580, AMS 5832 |
| Tubes/Tuyaux | Tubes, Tuyaux | Diamètre extérieur : 0,250″ – 6,000″ (6,35 mm – 152,4 mm) | ASTM A732, AMS 5759 |
Soudage et transformation
HY ST31 (Stellite 31) and UNS R30031 offer good weldability and machinability:
- Soudage: Peut être soudé en utilisant des méthodes standard telles que le soudage TIG et MIG avec un préchauffage et un traitement thermique post-soudage appropriés.
- Traitement: Usinables à l'aide d'outils en carbure, bien que des précautions soient nécessaires en raison de leur dureté et de leur ténacité élevées.
Avantages et inconvénients
| Aspect | Détails |
|---|---|
| Avantages | High wear resistance, excellent strength at elevated temperatures, good corrosion resistance, and versatility in various applications. |
| Désavantages | Coût plus élevé par rapport aux matériaux conventionnels, nécessite une expertise en manipulation en raison de leur haute résistance et dureté. |
Alliages similaires
| Nom de l'alliage | Comparaison |
|---|---|
| Cobalt Alloy 6 | Higher cobalt content, offering superior wear resistance and hardness compared to HY ST31 and UNS R30031. |
Comparaison d'alliages similaires
| Propriété/caractéristique | HY ST31 / UNS R30031 | Cobalt Alloy 6 |
|---|---|---|
| Teneur en cobalt (%) | 30,0 – 34,0 | 54,0 – 62,0 |
| Teneur en chrome (%) | 27.0 – 31.0 | 25.0 – 32.0 |
| Teneur en tungstène (%) | 12.0 – 15.0 | 8,0 – 10,0 |
| Dureté, Rockwell C (HRC) | 38 – 44 | 48 – 55 |
| Applications | Aerospace, Oil & Gas, Medical | Outils industriels, composants d'usure |
This detailed article provides a comprehensive introduction to HY ST31 (Stellite 31) and UNS R30031, highlighting their chemical composition, mechanical properties, performance characteristics, industry applications, available forms and sizes, production standards, welding and processing capabilities, as well as advantages, disadvantages, and comparisons with similar alloys. Engineers and professionals seeking durable materials for high-wear and corrosion-resistant applications will find this information valuable for selecting the appropriate alloy to meet their specific needs.