Aço inoxidável, Austenítico
S34700 (347) Stainless Steel Sheet
Columbium stabilizes this alloy making it immune to chromium carbide precipitation.
Alloy 347 is recommended for welded applications that can not tolerate a post anneal. The alloy can operate between 800-1600°F.
347 stainless steel is a high-performance austenitic stainless steel com niobium stabilization that ensures excellent corrosion resistance, mechanical strength, and high-temperature stability. It is widely used in chemical, industrial, aerospace, food processing, and high-temperature applications.
BAIXAR PDF
ATENÇÃO
Se você não encontrar o que procura, entre em contato com seu centro de serviço local com seus requisitos específicos.
347 Stainless Steel Related Specifications
| Sistema / Padrão | País / Região | Grau / Designação |
| AISI | EUA | 347 |
| UNS | Internacional | S34700 |
| PT-BR / nº de série. | Europa | 1.4550 |
| Nome em Português | Europa | X6CrNiNb18-10 |
| ASTM A240 | EUA | 347 (plate, sheet, strip) |
| ASTM A182 | EUA | F347 (forgings, flanges, fittings) |
| ASTM A213 | EUA | TP347 (boiler / HX tubes) |
| ASTM A312 | EUA | TP347 (seamless pipe) |
| GB | China | 06Cr18Ni11Nb |
| JIS | Japão | SUS347 |
| BS | Reino Unido | 347S31 |
| AFNOR | França | Z6CNb18-10 |
Propriedades
Composição Química
S34700 Sheet
ASTM A240
| Elemento Químico | % Presente |
| Carbono (C) | 0.00 - 0.08 |
| Cromo (Cr) | 17.00 - 19.00 |
| Níquel (Ni) | 9.00 - 13.00 |
| Manganês (Mn) | 0.00 - 2.00 |
| Fósforo (P) | 0.00 - 0.04 |
| Enxofre (S) | 0.00 - 0.03 |
| Silício (Si) | 0.00 - 0.75 |
| Nióbio (Colúmbio) (Nb) | 0.00 - 1.00 |
| Ferro (Fe) | Equilíbrio |
Propriedades Mecânicas
Sheet
ASTM A240
| Propriedade Mecânica | Valor |
| Tensão de Escoamento | 205 MPa |
| Resistência à Tração | 515 MPa |
| Alongamento A50 mm | 40 Minutos % |
Propriedades Físicas Gerais
| Propriedade Física | Valor |
| Densidade | 7.96 g/cm³ |
Applications of 347 Stainless Steel
347 stainless steel is a stabilized austenitic stainless steel containing niobium (columbium), which improves resistance to corrosão intergranular after exposure to high temperatures. Its excellent mechanical properties and corrosion resistance make it suitable for a wide range of high-temperature and industrial applications.
1. High-Temperature Applications
Furnace components and heat exchangers
Boiler parts, superheater and evaporator tubes
Exhaust stacks and high-temperature ducting
Industrial ovens and kilns
2. Chemical and Petrochemical Industry
Processing equipment and piping in moderately corrosive environments
Pressure vessels and tanks for chemical storage
Heat-resistant piping carrying steam or hot liquids
3. Food and Beverage Processing
Equipment exposed to elevated temperatures
Heat exchangers and evaporators
Components requiring good corrosion resistance and stability at high temperature
4. Aerospace and Automotive
Exhaust systems and turbochargers
High-temperature components in engines and power plants
5. Industrial Equipment
Springs, fasteners, and structural components for high-temperature service
Mechanical equipment exposed to heat and corrosion simultaneously
6. Architectural Applications
Structures and components exposed to outdoor weather and moderate corrosive conditions
Decorative elements requiring durability and stability at elevated temperatures
Resumo
347 stainless steel is ideal for high-temperature and industrial applications, where intergranular corrosion resistance, mechanical strength, and stability at elevated temperatures are critical. Common industries include chemical processing, food and beverage, aerospace, automotive, and industrial equipment.
Characteristics of 347 Stainless Steel
347 stainless steel is a stabilized austenitic stainless steel containing niobium (columbium), which enhances resistance to corrosão intergranular after exposure to high temperatures. It offers good mechanical properties, excellent corrosion resistance, and high-temperature stability, making it suitable for demanding applications.
1. High-Temperature Stability
Excelente resistência a corrosão intergranular after exposure to temperatures of 425–870°C (800–1600°F)
Niobium stabilization prevents precipitação de carbeto de cromo during welding and heat exposure
Suitable for furnace parts, heat exchangers, and boiler components
2. Resistência à Corrosão
Boa resistência a oxidation, atmospheric corrosion, and mild chemical attack
Performs better than 304 and similar to 321 in high-temperature corrosive environments
Low susceptibility to pitting and crevice corrosion in moderately aggressive media
3. Propriedades Mecânicas
High strength and toughness, even at elevated temperatures
Can be cold-worked to improve strength
Excellent ductility for forming, bending, and shaping
4. Weldability
Easily welded using conventional methods: TIG, MIG, SMAW, or resistance welding
Niobium stabilization reduces risk of sensibilização in the heat-affected zone
Suitable for welded components in chemical, food, and high-temperature applications
5. Formabilidade e Fabricação
Good cold and hot workability
Can be rolled, drawn, or pressed into complex shapes
Suitable for sheets, plates, tubes, and structural components
6. Heat Resistance
Pode resistir continuous service up to 870°C (1600°F)
Resistant to scaling and oxidation in oxidizing atmospheres
Resumo
347 stainless steel combines high-temperature stability, excellent corrosion resistance, and strong mechanical properties. Seu niobium stabilization prevents intergranular corrosion, making it ideal for high-temperature industrial equipment, chemical processing, aerospace, and food processing applications.
Informações Adicionais
Fabricação
Fabrication of 347 Stainless Steel
347 stainless steel is a aço inoxidável austenítico estabilizado com titânio designed to resist intergranular corrosion during welding and high-temperature service. It combines excellent corrosion resistance, good weldability, and mechanical strength, making it suitable for a wide range of fabrication processes in industrial and high-temperature applications.
Formando
347 stainless steel has good cold formability na condição recozida.
Can be bent, deep-drawn, stamped, and roll-formed.
Because of work-hardening, intermediate annealing may be required during extensive forming operations to restore ductility.
2. Corte e Cisalhamento
Can be cut with standard techniques such as shearing, sawing, and laser cutting.
Tools must be sharp to minimize work-hardening at the cut edges.
3. Usinagem
347 is moderately difficult to machine due to austenitic toughness and work-hardening tendency.
Usar carbide tooling for better performance, proper feed rates, and cooling lubricants to control heat and tool wear.
4. Soldagem
Excellent weldability with conventional processes: TIG, MIG, SMAW.
A estabilização com titânio previne corrosão intergranular near the weld.
Eletrodos de solda, como 347 or 308L are commonly used.
Post-weld annealing is typically não exigido for corrosion resistance, but stress relief may be applied in high-temperature applications.
5. Cold Working
Cold working increases strength significantly due to work-hardening.
Extensive cold work reduces ductility; recozimento may be required to restore formability for further fabrication.
6. Hot Working
Hot working is typically performed between 1010–1175°C (1850–2150°F).
Proper temperature control ensures uniform mechanical properties and prevents grain growth.
7. Surface Finishing
Can be supplied in a range of finishes (2B, BA, or polished).
Work-hardened areas may require additional finishing for aesthetics or corrosion resistance.
Resumo
347 stainless steel is versatile and easily fabricated, offering excellent weldability, corrosion resistance, and strength. Its titanium stabilization makes it particularly suitable for welding and high-temperature applications, while its workability allows for forming, machining, and finishing across a wide range of industrial uses.
Soldabilidade
Weldability of 347 Stainless Steel
347 stainless steel is a aço inoxidável austenítico estabilizado com titânio that offers excelsa soldabilidade. Its titanium content prevents the formation of chromium carbides during welding, reducing the risk of corrosão intergranular in the heat-affected zone (HAZ). This makes 347 highly suitable for welded structures and components exposed to elevated temperatures.
1. Compatible Welding Processes
TIG (GTAW) – Preferred for precision welding and thin sections.
MIG (GMAW) – Common for thicker sections and high-productivity applications.
Shielded Metal Arc Welding (SMAW) – Suitable for field and maintenance welding.
Resistance welding – Spot and seam welding can be used effectively.
2. Benefícios da Estabilização de Titânio
Titanium reacts with carbon to form stable titanium carbides.
Prevents precipitação de carbeto de cromo, avoiding sensitization in the HAZ.
Ensures corrosion resistance is maintained after welding, even without post-weld annealing.
3. Filler Material Selection
Filler metals matching 347 are commonly used for optimum corrosion resistance.
ER347 or 308L filler rods are suitable depending on base material thickness and application.
Low-carbon fillers reduce carbide precipitation risk in general austenitic stainless steel applications.
4. Heat Input and Distortion
347 has alta expansão térmica, which can lead to distortion if not controlled.
Usar low to moderate heat input to reduce warping and maintain dimensional stability.
Adequate fixturing and sequence planning help minimize residual stresses.
5. Post-Weld Treatment
Usually, post-weld annealing is não exigido because titanium stabilization protects against intergranular corrosion.
Stress relief may be applied for high-temperature service or when dimensional stability is critical.
6. Aplicações Relacionadas à Soldabilidade
High-temperature boilers and furnace components
Equipamentos para processamento químico e petroquímico
Heat exchangers
Pressure vessels and piping systems requiring welded assemblies
Resumo
347 stainless steel exhibits excelsa soldabilidade due to its titanium stabilization, allowing it to maintain corrosion resistance in welded areas without the need for extensive post-weld heat treatment. Proper filler selection, heat control, and welding technique ensure strong, durable, and corrosion-resistant welds suitable for high-temperature and industrial applications.
Usinabilidade
Machinability of 347 Stainless Steel
347 stainless steel, a aço inoxidável austenítico estabilizado com titânio, has usinabilidade moderada similar to other austenitic grades such as 304 and 321. While it is tougher and more work-hardening than carbon steels, careful tooling and machining practices allow for efficient processing and good surface finishes.
1. Comportamento de Encruamento
347 stainless steel exhibits work-hardening during cutting, which increases tool wear if not properly managed.
Continuous, consistent cutting helps prevent excessive hardening on the surface.
2. Recomendações de Ferramentas
Carbide tooling is preferred for higher productivity and tool life.
High-speed steel (HSS) tools can be used at slower cutting speeds with careful feed control.
Positive rake angles reduce cutting forces and heat generation.
3. Velocidades e Avanços de Corte
Slower cutting speeds than those used for carbon steels are recommended.
Usar moderate to heavy feeds to keep the tool engaged and minimize work-hardening.
4. Resfriamento e lubrificação
Aços inoxidáveis austeníticos possuem low thermal conductivity, so heat control is critical.
Flood coolant or high-performance cutting oils help reduce heat, improve surface finish, and extend tool life.
5. Formação de Cavaco
Chips are typically tough and stringy, making them difficult to evacuate.
Use chip breakers or insert geometries designed for stainless steel to manage chips effectively.
6. Acabamento Superficial
Good surface finishes can be achieved with proper tool geometry, cutting parameters, and cooling.
Avoid dwell or pauses on the workpiece, as these can create hardened spots and reduce finish quality.
Resumo
347 stainless steel has usinabilidade moderada compared with other austenitic grades. Success in machining relies on sharp tools, controlled cutting parameters, proper cooling, and feed rates to counteract work-hardening and achieve high-quality finished components.
Resistência à corrosão
Corrosion Resistance of 347 Stainless Steel
347 stainless steel is a aço inoxidável austenítico estabilizado com titânio with excellent corrosion resistance. The titanium stabilization prevents chromium carbide precipitation during welding, reducing the risk of corrosão intergranular, particularly in the heat-affected zone (HAZ). This makes 347 ideal for welded assemblies and high-temperature applications.
1. Resistência Geral à Corrosão
Funciona bem em atmospheric, industrial, and mildly corrosive environments.
Resistant to oxidation at moderate elevated temperatures.
Suitable for general chemical, petrochemical, and process equipment.
2. Resistência à Corrosão Intergranular
Titanium binds with carbon to form stable titanium carbides.
Prevents chromium depletion at grain boundaries, which avoids sensibilização.
Especially beneficial in welded areas where intergranular corrosion is a concern.
3. Resistance to Chlorides
Exhibits moderate resistance to chloride-induced corrosão por pites e frestas.
Not as resistant as Mo-bearing grades like 316, but better than carbon steels or unstabilized austenitic grades in welded components.
4. Corrosão em Alta Temperatura
Suitable for use in continuous service up to ~870°C (1600°F) in oxidizing atmospheres.
Titanium stabilization provides good resistance to carbide precipitation and oxidation during high-temperature service.
5. Comparison to Other Austenitic Grades
Better corrosion resistance than 304 in welded conditions due to titanium stabilization.
Slightly less corrosion-resistant than 316 in chloride-rich environments.
Superior intergranular corrosion resistance compared to unstabilized 321 or 304 stainless steels.
6. Applications Leveraging Corrosion Resistance
Heat exchangers and furnace components
Equipamentos químicos e petroquímicos
Pressure vessels and piping systems
Components exposed to elevated temperatures or welding
Resumo
347 stainless steel combines excellent general corrosion resistance with superior resistance to intergranular corrosion, making it highly suitable for welded and high-temperature applications. Titanium stabilization ensures reliable long-term performance, especially in industrial and chemical environments.
Laminação a Frio
Cold Working of 347 Stainless Steel
347 stainless steel is an austenitic, titanium-stabilized stainless steel with good cold-working properties. Cold working increases the material’s Força e dureza while reducing ductility. The titanium stabilization helps maintain corrosion resistance, even in heavily worked conditions.
1. Comportamento de Encruamento
347 stainless steel work-hardens during cold deformation, although slightly less aggressively than 301 or 304.
Strength increases significantly with deformation, but ductility decreases.
2. Processos de Trabalho em Comum para Gripe
Rolamento: For sheets, strips, and plates.
Desenho For wires, tubes, and rods.
Dobragem e Conformação: For clips, springs, and structural components.
Estampagem e Repuxo: For complex parts.
3. Mechanical Properties Control
Cold working allows precise adjustment of resistência à tração, limite de escoamento e dureza.
Trabalho a frio extensivo pode exigir intermediate annealing to restore ductility for further forming.
4. Efeito na Resistência à Corrosão
A estabilização com titânio previne precipitação de carbeto de cromo, maintaining corrosion resistance even after significant cold work.
Unlike unstabilized austenitic grades, 347 maintains resistance to intergranular corrosion in welded or heavily worked areas.
5. Considerações Pós-Formatação
In highly cold-worked parts, têmpera de recozimento can be performed to relieve residual stresses and restore formability if required.
Cold working may also induce some magnetism due to martensitic transformation, though minimal in 347 compared to 301.
6. Applications Utilizing Cold Work
Springs and clips
Structural components requiring high strength
Industrial equipment requiring formability and corrosion resistance
Tubes, rods, and wire for chemical and high-temperature service
Resumo
347 stainless steel exhibits good cold-working characteristics, allowing it to achieve higher strength through work hardening while maintaining corrosion resistance thanks to titanium stabilization. Proper management of deformation and occasional annealing enables high-performance components for industrial and high-temperature applications.
Tratamento Térmico
Heat Treatment of 347 Stainless Steel
347 stainless steel is a aço inoxidável austenítico estabilizado com titânio. Unlike martensitic or precipitation-hardening grades, it is not hardened by conventional heat treatment. Heat treatment is mainly used to restore ductility, relieve stresses, and maintain corrosion resistance, especially after cold working or welding.
1. Annealing / Solution Treatment
Propósito:
Relieve stresses from cold working or forming
Restore ductility
Dissolve any unwanted precipitates
Typical Temperature: 1010–1120°C (1850–2050°F)
Refrigeração: Rapid air or water quenching to preserve a fully austenitic structure
Efeito:
Returns mechanical properties to annealed condition
Maintains corrosion resistance due to titanium stabilization
2. Alívio do estresse
Propósito: Reduzir tensões residuais de conformação, dobramento ou soldagem
Faixa de Temperatura: 450–650°C (840–1200°F)
Efeito: Minimizes distortion and reduces the risk of stress corrosion cracking without significantly changing mechanical properties
3. Cold-Worked Condition Considerations
Cold working increases strength but reduces ductility.
Revenimento intermediário may be performed between forming operations to restore ductility and workability.
Repeated cold work and annealing allow precise control over strength and hardness.
4. Post-Weld Heat Treatment
Welding 347 stainless steel typically does not require post-weld annealing for corrosion resistance, thanks to titanium stabilization.
Stress relief annealing may be applied in high-temperature service or where dimensional stability is critical.
5. Limitações
Tratamento térmico faz não aumenta significativamente a dureza; 347 relies on cold working for strength enhancement.
Prolonged high-temperature exposure above ~500°C can reduce the effects of prior cold work.
Resumo
Heat treatment of 347 stainless steel is focused on stress relief, ductility restoration, and maintaining corrosion resistance, rather than hardening. Solution annealing and controlled stress relief help ensure optimal mechanical and chemical performance for welded, cold-worked, and high-temperature components.
Resistência ao calor
Heat Resistance of 347 Stainless Steel
347 stainless steel is a aço inoxidável austenítico estabilizado com titânio with good high-temperature properties. It is specifically designed for applications requiring resistance to carbide precipitation and oxidation em altas temperaturas.
1. Temperatura de Serviço Contínuo
Suitable for continuous service in oxidizing atmospheres up to ~870°C (1600°F).
A estabilização com titânio previne corrosão intergranular and maintains strength during long-term exposure to elevated temperatures.
Exposição Intermitente
Tolerar intermittent exposure up to ~925°C (1700°F) without significant scaling or degradation.
Useful for components subject to occasional thermal cycling or transient heating.
3. Resistência à Oxidação
Forma um camada protetora de óxido de cromo that resists scaling in oxidizing environments.
Not suitable for prolonged exposure to strongly oxidizing or sulfidizing atmospheres at extreme temperatures; for these, specialized high-temperature grades such as 310 are recommended.
4. Efeitos Térmicos nas Propriedades Mecânicas
Retains good tensile strength and ductility at elevated temperatures.
High-temperature exposure does not significantly reduce corrosion resistance, due to titanium stabilization.
Prolonged exposure above 900°C can lead to grain growth, which may reduce toughness.
5. Aplicações Relacionadas à Resistência ao Calor
Componentes de caldeira e forno
Heat exchangers
Equipamentos para processamento químico e petroquímico
High-temperature piping and welded assemblies
6. Comparison to Other Austenitic Grades
Heat resistance is better than 304 in welded or high-temperature applications.
Slightly lower high-temperature strength than 310 but more corrosion-resistant than unstabilized 304 in the HAZ.
Titanium stabilization ensures reliability in long-term service at elevated temperatures.
Resumo
347 stainless steel provides excelente desempenho em altas temperaturas up to ~870°C for continuous service. Its titanium stabilization prevents carbide precipitation, maintaining corrosion resistance and mechanical strength in welded and heat-exposed components, making it ideal for industrial and high-temperature applications.
Conformação a Quente
Heat Resistance of 347 Stainless Steel
347 stainless steel is a aço inoxidável austenítico estabilizado com titânio with good high-temperature properties. It is specifically designed for applications requiring resistance to carbide precipitation and oxidation em altas temperaturas.
1. Temperatura de Serviço Contínuo
Suitable for continuous service in oxidizing atmospheres up to ~870°C (1600°F).
A estabilização com titânio previne corrosão intergranular and maintains strength during long-term exposure to elevated temperatures.
Exposição Intermitente
Tolerar intermittent exposure up to ~925°C (1700°F) without significant scaling or degradation.
Useful for components subject to occasional thermal cycling or transient heating.
3. Resistência à Oxidação
Forma um camada protetora de óxido de cromo that resists scaling in oxidizing environments.
Not suitable for prolonged exposure to strongly oxidizing or sulfidizing atmospheres at extreme temperatures; for these, specialized high-temperature grades such as 310 are recommended.
4. Efeitos Térmicos nas Propriedades Mecânicas
Retains good tensile strength and ductility at elevated temperatures.
High-temperature exposure does not significantly reduce corrosion resistance, due to titanium stabilization.
Prolonged exposure above 900°C can lead to grain growth, which may reduce toughness.
5. Aplicações Relacionadas à Resistência ao Calor
Componentes de caldeira e forno
Heat exchangers
Equipamentos para processamento químico e petroquímico
High-temperature piping and welded assemblies
6. Comparison to Other Austenitic Grades
Heat resistance is better than 304 in welded or high-temperature applications.
Slightly lower high-temperature strength than 310 but more corrosion-resistant than unstabilized 304 in the HAZ.
Titanium stabilization ensures reliability in long-term service at elevated temperatures.
Resumo
347 stainless steel provides excelente desempenho em altas temperaturas up to ~870°C for continuous service. Its titanium stabilization prevents carbide precipitation, maintaining corrosion resistance and mechanical strength in welded and heat-exposed components, making it ideal for industrial and high-temperature applications.
