Se você estiver trabalhando em construção de carga média, maquinaria, ou projetos de infraestrutura, ST35 structural steel is a reliable, escolha econômica. Conhecido por sua boa conformabilidade, soldabilidade, e força equilibrada, é usado em tudo, desde estruturas de edifícios até sistemas de transporte. Este guia explica o que é ST35, como funciona, and where it adds the most value—so you can make confident material decisions.
1. Material Properties of ST35 Structural Steel
ST35’s performance is rooted in its carefully controlledcomposição química and predictable physical, mecânico, and functional traits. Below’s a detailed breakdown:
Composição Química: Simple, Balanced, and Cost-Effective
ST35 is a low-alloy structural steel—its composition focuses on basic elements to deliver reliability without extra alloy costs.
| Element | Content Range | Key Role |
|---|---|---|
| Carbon (C) | 0.14–0.22% | Provides moderateresistência à tracção while keeping the steel easy to weld |
| Manganese (Mn) | 0.35–0.65% | Enhances toughness and prevents cracking duringhot rolling |
| Silicon (E) | Up to 0.40% | Acts as a deoxidizer (removes oxygen to avoid porous defects in beams/columns) |
| Sulfur (S) | Max 0.050% | Strictly limited (high levels reducesoldabilidade and cause brittleness) |
| Phosphorus (P) | Max 0.040% | Controlled to avoid cold brittleness (protects performance in cool climates) |
| Chromium (Cr), Níquel (Em), Molybdenum (Mo), Vanadium (V), Cobre (Cu) | Trace amounts or absent | Kept low to keep costs down (ST35 prioritizes affordability over extreme strength) |
Propriedades Físicas: Consistent for Easy Design
ST35’s physical traits are consistent across batches, making it simple to integrate into projects:
- Densidade: ~7850 kg/m³ (same as most structural steels—easy to calculate weight for beams or vehicle frames)
- Thermal conductivity: 50–60 W/(m·K) (spreads heat evenly—reduces warping when welding industrial structures)
- Specific heat capacity: ~490–500 J/(kg·K) (resists temperature spikes—reliable for outdoor infrastructure like highway bridges)
- Coefficient of thermal expansion: 12–13.5 µm/(m·K) (low enough to handle seasonal temperature swings in transmission towers)
- Magnetic properties: Ferromagnetic (easy to inspect with magnetic particle testing for defects in machinery frames)
Propriedades Mecânicas: Balanced for Mid-Load Projects
ST35’s mechanical strength is tailored for applications that don’t require ultra-high strength—but still need durability.
| Mechanical Property | Valor típico | Why It Matters for ST35 Users |
|---|---|---|
| Resistência à tracção | 335–435 MPa | Handles moderate pulling forces (ideal forbuilding columns ouconveyor systems) |
| Força de rendimento | ~235 MPa | Maintains shape under load (prevents bending insuspension components ouequipment supports) |
| Elongation at break | 25–35% | Stretches easily without breaking (simple to form intobeams ouquadros de veículos) |
| Reduction of area | 40–50% | Indicates high ductility (avoids snapping intrusses ouengine parts) |
| Dureza | 130–190 HB (Brinell); 85–100 HRB (Rockwell) | Soft enough for easyusinabilidade (cuts quickly into custom parts) |
Other Key Properties
- Resistência à corrosão: Low (needs paint, galvanizing, or coating for outdoor use—critical for marine structures ou wind turbine towers)
- Fatigue resistance: Moderado (handles repeated stress in conveyor systems ou quadros de veículos for years)
- Weldability: Bom (requires minimal pre-heating—perfect for on-site welding of bridge girders ou factory frames)
- Usinabilidade: Fair to good (cuts easily with standard tools—saves time when making engine parts ou safety structures)
- Formabilidade: Bom (bends with basic press brakes—ideal for shaping highway barriers ou building trusses)
2. Applications of ST35 Structural Steel
ST35’s balance of affordability, conformabilidade, and strength makes it a top choice across industries. Here’s where it shines:
Construction
ST35 is a workhorse for mid-rise buildings, pontes, and industrial structures:
- Beams, columns, and frames: Supports floors and roofs in 5–15 story buildings (por exemplo, office buildings, small apartment complexes).
- Bridge girders and trusses: Used in medium-span bridges (50–100 meters) for local roads or rural highways.
- Industrial structures: Frames for factories, warehouses, or workshops (handles light-to-moderate equipment loads).
- Example: A European construction firm used ST35 for a 12-story office building—its conformabilidade let them create custom beam shapes, e soldabilidade cut on-site construction time by 15%.
Infrastructure
ST35 keeps critical infrastructure running smoothly:
- Railway tracks and supports: Holds rail lines in place (isso é resistência à fadiga handles repeated train loads).
- Highway bridges and barriers: Makes up guardrails and small bridge components (affordable enough for large-scale projects).
- Marine structures (piers, docks): Used in low-salt areas (with galvanizing) for small pier frames or walkways.
- Example: A Southeast Asian DOT used ST35 for highway guardrails—they cost 30% less than stainless steel, and with paint, lasted 10 years without rust.
Mechanical Engineering
Machinery makers rely on ST35 for easy-to-shape, peças duráveis:
- Machinery frames: Holds motors and components in place for small-to-medium machines (por exemplo, packaging equipment).
- Equipment supports: Bases for generators, compressors, or pumps (isso é yield strength prevents tipping).
- Conveyor systems: Frames and rollers for moving grain, gravel, or packaged goods (ductilidade handles minor impacts).
- Example: A U.S. manufacturing plant used ST35 for conveyor frames—they were 20% cheaper than Grade 50 steel and lasted 8 years with no repairs.
Automotivo & Energy
ST35 plays a role in vehicle and energy projects where cost and formability matter:
- Automotivo: Vehicle frames for small cars, suspension components for trucks, and low-stress engine parts (por exemplo, brackets).
- Energy: Secondary components in wind turbine towers (por exemplo, access ladders) e power plant structures (por exemplo, pipe supports).
- Example: A Chinese automaker used ST35 for compact car frames—its conformabilidade let them create aerodynamic shapes, e usinabilidade speeded up production.
3. Manufacturing Techniques for ST35 Structural Steel
Producing ST35 is straightforward—its simple composition means fewer steps than high-alloy steels. Here’s the process:
Primary Production: Making Raw ST35 Steel
- Blast furnace process: Melts iron ore with coke and limestone to produce pig iron (the base material for ST35).
- Basic oxygen steelmaking (BOS): Blows pure oxygen into pig iron to adjust carbon content (to 0.14–0.22%) and remove impurities like sulfur.
- Electric arc furnace (EAF): Melts scrap steel (used for smaller batches of ST35—more flexible for custom orders).
Secondary Production: Shaping ST35 into Usable Forms
- Hot rolling: Heats ST35 to 1100–1250°C, then rolls it into beams, columns, plates, ou bars (most common method—boosts strength and ductility).
- Cold rolling: Rolls ST35 at room temperature for parts that need a smooth surface (por exemplo, automotive body components or small engine parts—improves precision but reduces ductility slightly).
Tratamento térmico: Optimizing ST35’s Performance
- Normalizing: Heats ST35 to 850–900°C, then cools in air (refines grain structure—enhances resistência à tracção para bridge girders ou machinery frames).
- Annealing: Heats to 700–750°C, then cools slowly (softens the steel—improves usinabilidade for cutting custom conveyor parts ou suspension components).
Fabricação: Turning ST35 into Finished Products
- Cutting: Usos oxy-fuel cutting (thick ST35 plates for building columns), plasma cutting (medium-thickness sheets for barriers), ou corte a laser (thin parts for engine brackets).
- Bending: Uses press brakes or rolling machines (easy to shape into curved beams ou vehicle frame rails—thanks to ST35’s high conformabilidade).
- Welding: Joins parts with arc welding (on-site construction), MIG welding (high-volume parts like conveyor frames), ou TIG welding (precision parts like engine components).
- Assembly: Puts together fabricated parts (por exemplo, attaching beams para columns) using bolts or welding.
4. Case Studies: ST35 Structural Steel in Action
These real-world examples show how ST35 solves problems and saves money for businesses.
Estudo de caso 1: 12-Story Office Building (Germany)
- Challenge: Need an affordable steel for beams and columns that’s easy to weld on-site.
- Solution: Used ST35—its soldabilidade let workers join parts without expensive pre-heating, e conformabilidade allowed custom beam shapes for the building’s unique design.
- Results: Construction finished 3 weeks early; material costs were 25% lower than using high-strength steel. The building’s structure remains stable after 10 years.
Estudo de caso 2: Highway Guardrails (Thailand)
- Challenge: Need a low-cost steel for 50 km of guardrails that can withstand rain and mild humidity.
- Solution: Used ST35 with a powder-coat finish—its acessibilidade fit the budget, and the coating boosted resistência à corrosão.
- Results: Guardrails cost $15/linear meter (contra. $20 for stainless steel) and showed no rust after 8 years. Maintenance costs dropped by 40%.
Estudo de caso 3: Conveyor Frames (U.S. Manufacturing Plant)
- Challenge: Need a steel for conveyor frames that’s easy to cut and lasts under daily use.
- Solution: Used ST35—its usinabilidade let the plant cut custom parts in-house, e resistência à fadiga handled 12-hour daily operation.
- Results: Conveyor frames lasted 8 years (contra. 5 years for aluminum); in-house machining saved $5,000/year in outsourcing costs.
5. ST35 Structural Steel vs. Outros materiais
How does ST35 stack up against alternatives? This table helps you choose the right material for your project:
| Material | Yield Strength (MPa) | Custo (per kg) | Key Advantage | Best For |
|---|---|---|---|---|
| Aço Estrutural ST35 | ~235 | $1.20–$1.80 | Balanced strength, conformabilidade, e custo | Mid-rise buildings, conveyor frames, guardrails |
| Alumínio (6061-T6) | 276 | $3.00–$4.00 | Lightweight, melhor resistência à corrosão | Aircraft parts, lightweight vehicle components |
| Aço inoxidável (304) | 205 | $4.00–$5.00 | Excellent corrosion resistance | Coastal infrastructure, food-processing equipment |
| Cast Iron | ~200 (compressive) | $1.50–$2.00 | High compressive strength | Manhole covers, low-impact machinery bases |
| Concrete | 40 (compressive) | $0.10–$0.20 | Ultra-low cost, high compressive strength | Building foundations, low-rise walls |
Key Takeaways
- Cost vs. Desempenho: ST35 is cheaper than aluminum or stainless steel while offering better tensile strength than cast iron or concrete.
- Workability: ST35 is easier to weld and form than stainless steel or cast iron—saves time on fabrication.
- Valor: It’s the best choice for mid-load projects where you don’t need ultra-high strength but want reliability (por exemplo, small office buildings, conveyor systems).
6. Yigu Technology’s Perspective on ST35 Structural Steel
Na tecnologia Yigu, we see ST35 as a “workhorse material” for mid-scale projects. Its biggest strength isn’t just its technical properties—it’s its ability to balanceacessibilidade, conformabilidade, econfiabilidade—solving the “cost vs. performance” problem many clients face. We recommend pairing ST35 with galvanizing for outdoor use (comohighway bridges) and usingnormalizing heat treatment for parts needing extra strength (e.g.,machinery frames). For projects that don’t require Grade 50 ou 80 aço, ST35 is the smart, escolha econômica.
FAQ About ST35 Structural Steel
1. Can ST35 be used outdoors?
Yes—but it needs protection. ST35 has lowresistência à corrosão, so add a coating likehot-dip galvanizing, epoxy paint, or zinc spray. We’ve supplied galvanized ST35 forhighway guardrails esmall piers—they lasted 10+ years in rainy or humid climates.
2. Is ST35 strong enough for building columns?
Absolutely—for mid-rise buildings (5–15 stories). ST35’syield strength (~235 MPa) eresistência à tracção (335–435 MPa) easily support floor loads and wind forces in these structures. For taller buildings (20+ histórias), we recommend higher-strength steel like Grade 50.
3. How does ST35 compare to Grade 50 aço?
ST35 is cheaper and more formable, but Grade 50 is stronger. ST35 costs ~30% less and is easier to weld/form—ideal for mid-load projects (por exemplo, conveyor frames). Nota 50 has a higheryield strength (~345 MPa)—better for tall buildings or heavy machinery.