Se você estiver comprando aço inoxidável para utensílios de cozinha, equipamento de processamento de alimentos, ou peças arquitetônicas, 304 2B stainless steel is likely your top choice. É o tipo de aço inoxidável laminado a frio mais comum - oferecendo um acabamento suave, acabamento uniforme, resistência à corrosão confiável, e fácil conformabilidade. Este guia detalha tudo que você precisa saber para trabalhar, especificar, e compre 304 2B stainless steel confidently.
1. 304 2B Aço Inoxidável: Propriedades & Características
304 2B’s appeal comes from its balanced mix of mechanical strength, resistência à corrosão, and workability—perfect for both structural and decorative uses.
Key Mechanical & Propriedades Físicas
| Propriedade | Valor típico | Why It Matters for Your Projects |
|---|---|---|
| Resistência à tracção | 515 MPa (74,700 psi) | Strong enough for appliances (por exemplo, sink edges) and light structural parts |
| Força de rendimento | 205 MPa (29,700 psi) | Resists bending in high-use items (por exemplo, elevator panels) |
| Dureza | 92 HRB (Rockwell B) / 200 Alta tensão | Soft enough to cut/shape, tough enough to avoid dents |
| Densidade | 7.93 g/cm³ | Lightweight for architectural cladding, heavy enough for durability |
| Condutividade Térmica | 16.2 S/m·K (at 100°C) | Transfers heat moderately—good for HVAC ducting |
| Coeficiente de Expansão Térmica | 17.3 µm/m·K (20–100ºC) | Predictable expansion (critical for precision parts like appliance doors) |
| Magnetic Permeability | 1.02 μr (recozido) | Near non-magnetic—safe for electronics and medical equipment |
| Resistência à corrosão | Excelente (resiste à água, ácidos suaves) | Won’t rust in kitchens or indoor spaces—though less durable than 316 in saltwater |
Corrosion Comparison: 304 2B resists rust in most indoor environments, mas 316 (with molybdenum) lasts 3x longer in coastal or chemical-rich areas. A restaurant used 304 2B for indoor sinks—they stayed rust-free for 8 years—while outdoor railings (exposed to rain) needed repainting after 3 anos (316 would have avoided this).
2. 304 2B Aço Inoxidável: Fabricação & Processamento
The “2B” in 304 2B refers to its cold-rolled finish—a key step that gives it a smooth, consistent surface. Here’s how it’s made and processed:
Etapa 1: Core Manufacturing Process
- Fusão & Fundição: Iron ore, cromo (18–20%), níquel (8–10.5%), and other alloys are melted in an electric arc furnace to make 304 aço inoxidável. The molten steel is cast into slabs.
- Hot Rolling: Slabs are heated to 1,100°C and rolled into thick coils (called “hot-rolled coils”).
- Cold Rolling: Hot-rolled coils are passed through cold rollers (temperatura ambiente) to reduce thickness (por exemplo, from 10mm to 1mm) and smooth the surface. This step creates the “2B” finish—defined as a cold-rolled, recozido, and pickled finish (annealing softens the steel; pickling removes oxide scale).
- Passivação: The final 2B coils/sheets undergo surface passivation (a nitric acid bath) to strengthen the chromium oxide passivation layer—boosting corrosion resistance.
Etapa 2: Post-Manufacturing Processing
Once you have 304 2B coils or sheets, common processing methods include:
- Corte: Coils are cut into narrower strips (por exemplo, 50mm de largura) for small parts like trim.
- Supressão: Sheets are punched into flat shapes (por exemplo, 30cm circles for sink bases).
- Corte a laser: Precision cutting for complex shapes (por exemplo, decorative architectural panels). Recommended parameters: cutting speed 15–25 m/min, nitrogen assist gas (prevents oxidation).
- Deep Drawing: 304 2B’s high formability lets it be stretched into 3D shapes (por exemplo, pots, pans, or sink bowls). A cookware manufacturer uses deep drawing to make 304 2B pots—no cracking, even with tight curves.
- Soldagem: TIG welding is best for 304 2B—use ER308L filler wire to avoid weld decay. Post-weld passivation ensures the weld area stays corrosion-resistant.
Pro Tip: Avoid overheating during welding—temperatures above 800°C can weaken the passivation layer. A fabricator once skipped passivation after welding 304 2B elevator panels—the welds rusted within 6 meses.
3. 304 2B Aço Inoxidável: Aplicativos & Indústrias
304 2B’s smooth finish, resistência à corrosão, and affordability make it the most widely used stainless steel grade. Here are its top uses:
Comida & Beverage Industry
- Utensílios de cozinha: Refrigerator doors, oven interiors, and dishwashers use 304 2B—its non-porous surface won’t trap food bacteria, and it’s easy to clean. 90% of stainless steel sinks are 304 2B.
- Equipamento de processamento de alimentos: Mixers, correias transportadoras, and storage tanks rely on 304 2B’s FDA compliance (safe for food contact). A bakery used 304 2B for dough mixers—they’re still in use after 10 anos.
Arquitetônico & Construção
- Architectural cladding: Interior walls, elevator panels, and handrails use 304 2B’s smooth finish for a modern look. A hotel lobby used 304 2B panels—they hide fingerprints better than mirror-polished steel.
- Dutos HVAC: 304 2B’s corrosion resistance prevents rust from condensation in ducts—lasts 2x longer than galvanized steel.
Médico & Farmacêutico
- Equipamento farmacêutico: Tablet presses and drug storage bins use 304 2B—its easy-to-sterilize surface meets GMP standards.
- Medical carts: 304 2B’s durability stands up to daily cleaning with harsh disinfectants.
Automotivo & Bens de consumo
- Acabamento automotivo: Car door handles and dashboard accents use 304 2B for a sleek, rust-resistant finish.
- Bens de consumo: Garrafas de água, talheres, and watch cases often use 304 2B—affordable yet long-lasting.
4. 304 2B Aço Inoxidável: Notas, Padrões & Certificações
To ensure you’re getting high-quality 304 2B, always check for compliance with global standards and certifications:
Key Standards (Global Equivalents)
| Region | Standard Designation | Key Specification Details |
|---|---|---|
| NÓS. | ASTM A240 304 2B | Defines cold-rolled finish, thickness tolerances (±0,02mm), and chemical composition |
| Europa | EM 1.4301 2B | Equivalent to ASTM A240; requires EN 10204 3.1 certificação |
| Japan | JIS SUS304 2B | Focuses on surface finish (Ra 0.4–1.6 µm) e conformabilidade |
| Global | ISO 9445 | Covers cold-rolled stainless steel finishes, including 2B |
Critical Certifications
- Conformidade com a FDA: Mandatory for food-contact parts (por exemplo, pias, mixers).
- NSF/ANSI 51: Proves suitability for food-processing equipment.
- RoHS/REACH: Ensures no harmful substances (por exemplo, lead) for electronics or consumer goods.
- EM 10204 3.1 Mill Test Certificate: Confirms chemical composition, propriedades mecânicas, and finish—always ask suppliers for this.
Exemplo: A food equipment maker needed 304 2B sheets for a new mixer line. They only worked with suppliers who provided ASTM A240 specs and FDA certification—avoiding costly recalls later.
5. 304 2B Aço Inoxidável: Supply Chain & Aquisições
Buying 304 2B efficiently means understanding pricing, lead times, and stock options. Here’s what you need to know:
Preços & Cost Factors (2024 Estimates)
| Product Type | Price per kg | Key Cost Drivers |
|---|---|---|
| 304 2B Coils (1mm de espessura) | $3.20–$3.80 | LME nickel price (304 has 8–10.5% nickel; nickel price changes affect 304 2B costs by ~15% annually) |
| 304 2B Sheets (1mm x 1x2m) | $3.50–$4.20 | Processamento (cutting to size) adds 10–15% to coil prices |
Procurement Tips
- Stock Sizes: Common coil widths are 1219mm (4pés) and 1524mm (5pés); common sheet sizes are 1x2m and 2x3m. Ordering stock sizes cuts lead time by 50% (custom sizes take 2–3 weeks longer).
- Minimum Order Quantity (Quantidade mínima): Coils typically have a 500kg MOQ; sheets have a 100kg MOQ. Smaller orders (por exemplo, 50kg) are possible but cost 20% mais.
- Tempo de espera: From Chinese suppliers (major 304 2B producers), lead time is 2–4 weeks for stock; 4–6 weeks for custom.
- Incoterms: Use FOB (Free On Board) for sea shipping—you control freight and save 10–15% vs. DDP (Delivered Duty Paid).
- Embalagem: Coils are wrapped in VCI film (prevents rust during shipping); sheets are packed in wooden crates. Ask for waterproof packaging if shipping to humid regions.
Estudo de caso: A furniture maker ordered 1,000kg of 304 2B sheets (stock size 1x2m) FOB Shanghai. Eles salvaram $500 contra. custom sizes and received the order in 3 weeks—perfect for their production timeline.
Yigu Technology’s Perspective
Na tecnologia Yigu, 304 2B stainless steel is our top-selling grade for its versatility in food, architectural, e bens de consumo. We supply ASTM A240/EN 1.4301 304 2B coils (1219mm largura, 0.5–3mm thickness) and sheets, with full certifications (FDA, EM 10204 3.1). We offer slitting/blanking services to cut costs for clients, and our stock lead time is just 2 semanas. We also track LME nickel prices daily, helping clients lock in rates to avoid budget surprises. Para projetos de qualidade alimentar, we provide additional NSF/ANSI 51 documentation—ensuring compliance from factory to finished product.
Perguntas frequentes
- Can 304 2B stainless steel be used outdoors?
It can, but only in dry, low-salt environments (por exemplo, inland homes). In coastal areas, salt spray will cause rust within 2–3 years—use 316 2B instead. If you must use 304 2B outdoors, apply a clear stainless steel sealant every 6 meses. - Is 304 2B stainless steel magnetic?
Annealed 304 2B is near non-magnetic (magnetic permeability 1.02 μr). No entanto, cold working (por exemplo, bending or stamping) can make small areas slightly magnetic—this is normal and doesn’t affect performance. - How do I clean 304 2B stainless steel to prevent rust?
Use mild soap and warm water for daily cleaning—avoid abrasive sponges (they scratch the passivation layer). For tough stains (por exemplo, food grease), use a vinegar-water solution (1:1 ratio) and wipe dry immediately. Never use bleach or ammonia—they break down the passivation layer and cause rust.