1.4547 / UNS S31254 / F44 / 254 SMO: Product Introduction
1.4547, also known as UNS S31254, F44, or commonly referred to as 254 SMO, is a high-alloy austenitic stainless steel with excellent corrosion resistance. This article provides a detailed introduction to 1.4547/UNS S31254/F44/254 SMO, covering its chemical composition, mechanical properties, performance at different temperatures, industry applications, shapes and sizes, production standards, welding and processing capabilities, advantages and disadvantages, and a comparison with similar alloys.
Composizione chimica
1.4547/UNS S31254/F44/254 SMO has a specific chemical composition that contributes to its corrosion resistance and mechanical properties:
| Elemento | Composizione (%) |
|---|---|
| Cromo (Cr) | 19.5 – 20.5 |
| Nichel (Ni) | 17.5 – 18.5 |
| Molibdeno (Mo) | 6.0 – 6.5 |
| Rame | 00,5 – 1,0 |
| Azoto (N) | 0.18 – 0.22 |
| Carbonio (C) | 00,020 massimo |
| Silicon (Si) | 00,80 massimo |
| Manganese (Mn) | 1,00 massimo |
| Fosforo (P) | 00,030 massimo |
| Zolfo (S) | 00,010 massimo |
Proprietà meccaniche
1.4547/UNS S31254/F44/254 SMO exhibits excellent mechanical properties suitable for various applications:
| Proprietà | Valore |
|---|---|
| Resistenza alla trazione, ksi (MPa) | 100 (690) min |
| Limite di snervamento (compensazione dello 0,2%), ksi (MPa) | 50 (345) min |
| Allungamento (% in 2 pollici) | 35 min |
| Durezza, Rockwell B (HRB) | 55 max |
Caratteristiche prestazionali
1.4547/UNS S31254/F44/254 SMO offers outstanding performance across diverse conditions:
- Resistenza alla corrosione: Excellent resistance to both uniform corrosion and localized corrosion, including pitting and crevice corrosion, in chloride-containing environments.
- High Temperature Strength: Maintains strength and toughness at elevated temperatures, suitable for applications in marine and chemical processing industries.
- Saldabilità: Good weldability with conventional methods, such as TIG and MIG welding, ensuring ease of fabrication.
Applicazioni industriali
1.4547/UNS S31254/F44/254 SMO is utilized in industries requiring robust corrosion resistance and high strength:
| Settore industriale | Applicazioni |
|---|---|
| Elaborazione chimica | Heat exchangers, evaporators, and reactor tanks. |
| Olio e gas | Offshore platforms, pipelines, and valves in harsh environments. |
| Marino | Seawater desalination, marine exhaust systems, and shipbuilding. |
Forme e dimensioni
1.4547/UNS S31254/F44/254 SMO is available in various forms and sizes to meet specific application needs:
- Forme: Sheets, plates, bars, tubes, pipes, fittings, and welding consumables.
- Taglie: Thickness ranging from 0.1 mm to 50 mm for plates, and diameter ranging from 6 mm to 300 mm for round bars.
Standard di produzione
1.4547/UNS S31254/F44/254 SMO adheres to international production standards ensuring quality and performance:
| Forma del prodotto | Forme disponibili | Taglie disponibili | Standard di produzione |
|---|---|---|---|
| Lastre/Fogli | Fogli, Piatti | Spessore: 0,1 mm – 50 mm | ASTM A240, EN 10088 |
| Barre/Aste | Barre tonde, Barre quadrate | Diametro: 6 mm – 300 mm | ASTM A276, EN 10088 |
| Tubi/tubi | Senza soluzione di continuità, saldato | Diametro esterno: 6 mm – 300 mm | ASTM A312, ASTM A358 |
Saldatura e lavorazione
1.4547/UNS S31254/F44/254 SMO offers good weldability and processing characteristics:
- Saldatura: Can be welded using standard methods like TIG, MIG, and submerged arc welding, with post-weld heat treatment recommended to maintain corrosion resistance.
- Lavorabilità: Machinable with appropriate tooling and cutting speeds due to its high work hardening rate.
Vantaggi e svantaggi
| Aspetto | Dettagli |
|---|---|
| Vantaggi | Exceptional corrosion resistance, high strength, excellent weldability, and suitability for critical applications in aggressive environments. |
| Svantaggi | Higher initial cost compared to standard stainless steels, requires expertise in handling and fabrication due to its high alloy content. |
Similar Alloys
| Alloy Name | Confronto |
|---|---|
| 904L (UNS N08904) | Lower alloy content, slightly lower corrosion resistance compared to 1.4547/UNS S31254/F44/254 SMO, but more cost-effective. |
| Duplex Stainless Steels (e.g., UNS S31803) | Offers a balance of strength and corrosion resistance, suitable for similar applications in marine and chemical industries. |
Comparison of Similar Alloys
| Proprietà/funzionalità | 1.4547/UNS S31254/F44/254 SMO | 904L (UNS N08904) | Duplex Stainless Steel (UNS S31803) |
|---|---|---|---|
| Contenuto di cromo (%) | 19.5 – 20.5 | 20.0 – 25.0 | 21.0 – 23.0 |
| Contenuto di nichel (%) | 17.5 – 18.5 | 23.0 – 28.0 | 4.5 – 6.5 |
| Contenuto di molibdeno (%) | 6.0 – 6.5 | 4.0 – 5.0 | 2.5 – 3.5 |
| Resistenza alla corrosione | Eccellente resistenza alla corrosione indotta da cloruri, compresa vaiolatura e corrosione interstiziale. | Good corrosion resistance, lower than 1.4547/UNS S31254/F44/254 SMO in chloride environments. | Balanced corrosion resistance, lower than 1.4547/UNS S31254/F44/254 SMO in extreme chloride environments. |
| Applicazioni | Chemical processing, oil and gas, marine environments. | Chemical and pharmaceutical industries, paper production. | Petrolio e gas, lavorazioni chimiche, ambienti marini. |
This comprehensive article introduces 1.4547/UNS S31254/F44/254 SMO, highlighting its 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 highly corrosion-resistant materials for critical applications will find this information valuable in selecting the appropriate alloy to meet specific operational requirements.