Aço para rolamento EN 100CrMo7: Precisa saber sobre propriedades e usos

Se você trabalha em setores como automotivo, mineração, ou aeroespacial, você entende a importância de um aço para rolamentos confiável. EN 100CrMo7 bearing steel—a European-standard alloy with added molybdenum—stands out for its excellent fatigue resistance and hardenability. Este guia irá guiá-lo através de suas principais propriedades, aplicações do mundo real, processo de fabricação, e como ele se compara a outros materiais, helping you make informed decisions for your projects.

1. Material Properties of EN 100CrMo7 Bearing Steel

EN 100CrMo7’s unique composition, especially the addition of molybdenum, gives it distinct advantages over standard bearing steels. Let’s break down its properties in detail.

1.1 Composição Química

EN 100CrMo7 follows strict European standards (EM 10083-3), garantindo qualidade consistente. Abaixo está sua composição química típica:

1.2 Propriedades Físicas

These properties describe how EN 100CrMo7 behaves under physical conditions like temperature and magnetism:

• Densidade: 7.85 g/cm³ (same as most carbon-chromium-molybdenum steels)
• Ponto de fusão: 1,410 – 1,450 °C (2,570 – 2,640 °F)
• Condutividade Térmica: 45.5 C/(m·K) no 20 °C (temperatura ambiente)
• Coeficiente de Expansão Térmica: 11.4 × 10⁻⁶/°C (de 20 – 100 °C)
• Propriedades Magnéticas: Ferromagnético (atrai ímãs), making it easy to sort and inspect.

1.3 Propriedades Mecânicas

Mechanical properties determine how EN 100CrMo7 performs under force. Todos os valores abaixo são medidos após tratamento térmico padrão (têmpera e revenido):

1.4 Outras propriedades

EN 100CrMo7’s standout properties make it ideal for high-demand applications:

• Resistência ao desgaste: Alto carbono e cromo formam carbonetos duros, reduzindo o desgaste por contato rolante ou deslizante.
• Resistência à fadiga: Molybdenum improves its ability to withstand millions of load cycles—critical for long-lasting bearings in heavy machinery.
• Resistência à corrosão: Moderado; requires coatings (like zinc plating or nitriding) para ambientes úmidos ou agressivos (inferior ao aço inoxidável).
• Temperabilidade: Excellent—can be heat-treated to uniform hardness even in thick sections, ensuring consistent performance in large components.
• Estabilidade Dimensional: Maintains shape under temperature changes and stress, perfect for precision parts like bearing races.

2. Applications of EN 100CrMo7 Bearing Steel

EN 100CrMo7’s combination of strength, resistência, and wear resistance makes it suitable for a wide range of high-stress applications. Aqui estão seus usos mais comuns:

• Rolamentos: The primary application—including heavy-duty ball bearings, rolamentos de rolos, and needle bearings for industrial machinery and mining equipment.
• Elementos rolantes: Bolas, rolos, or needles inside bearings rely on EN 100CrMo7’s wear resistance to handle heavy loads.
• Corridas: Inner and outer rings of bearings (onde os elementos rolantes se movem) are often made from this steel for durability.
• Componentes Automotivos: High-stress parts like camshafts, elevadores de válvula, and transmission gears—especially in heavy-duty trucks.
• Máquinas Industriais: Caixas de velocidades, sistemas de transporte, and pumps that operate under high loads and long hours.
• Componentes Aeroespaciais: Small but critical bearings in aircraft engine accessories and landing gear (where reliability is non-negotiable).
• Dispositivos Médicos: Precision bearings in surgical tools and diagnostic equipment (thanks to its dimensional stability).
• Motores Elétricos: Bearings in large industrial motors that generate high heat (benefiting from molybdenum’s high-temperature strength).
• Agricultural Machinery: Bearings in tractors and harvesters that handle dusty, high-load conditions.
• Mining Equipment: Bearings in crushers and conveyor belts—where resistance to wear and impact is essential.

3. Manufacturing Techniques for EN 100CrMo7

Producing EN 100CrMo7 requires precise steps to meet European standards and ensure optimal performance. Here’s the typical manufacturing process:

1. Siderurgia:

• Most EN 100CrMo7 is produced using an Forno Elétrico a Arco (EAF) (for recycling scrap steel) ou um Forno de oxigênio básico (BOF) (para produção à base de minério de ferro). The process focuses on adjusting the chemical composition—especially adding molybdenum—to meet EN 10083-3 requisitos.

2. Rolando:

• Depois da siderurgia, o metal é Laminado a Quente (no 1,100 – 1,200 °C) into billets, bares, or sheets to shape it. Para peças de precisão, é então Laminado a Frio (à temperatura ambiente) para melhorar o acabamento superficial e a precisão dimensional.

3. Tratamento térmico:

• This step is crucial to unlock EN 100CrMo7’s full potential:
• Têmpera: Heat the steel to 830 – 870 °C, then rapidly cool it in oil or water to harden it.
• Temperamento: Reaquecer para 160 – 220 °C to reduce brittleness while maintaining high hardness and toughness.
• Carburização: Às vezes usado para peças que necessitam de uma camada externa dura (por exemplo, dentes de engrenagem)—heat in a carbon-rich atmosphere to increase surface carbon content.

4. Precision Forging:

• For complex shapes (like custom bearing components), the steel is heated and forged into near-final shapes. This improves grain structure and enhances mechanical properties.

5. Usinagem:

• Tratamento pós-térmico, parts are machined to their final dimensions using Virando (para peças cilíndricas como pistas de rolamento) ou Moagem (para superfícies ultra-lisas, which reduce friction in bearings).

6. Tratamento de superfície:

• Etapas opcionais para melhorar o desempenho:
• Nitretação: Creates a hard outer layer to boost wear and corrosion resistance.
• Escurecimento: Forms a protective oxide layer to prevent minor rust.

7. Controle de qualidade:

• Rigorous inspections ensure quality:
• Análise química (para verificar o conteúdo do elemento).
• Teste de dureza (usando máquinas Rockwell ou Vickers).
• Testes não destrutivos (ultrasonic testing to detect internal cracks).
• Verificações dimensionais (using calipers or CNC measuring tools to ensure parts fit).

4. Estudos de caso: EN 100CrMo7 in Action

Real-world examples highlight how EN 100CrMo7 solves industry challenges.

Estudo de caso 1: Mining Equipment Bearing Reliability

A mining company faced frequent bearing failures in their conveyor belt systems (lasting only 3 meses). The original bearings used standard 100Cr6 steel, which couldn’t handle the high impact and dust. Switching to EN 100CrMo7 bearings—paired with nitriding surface treatment—extended bearing life to 12 meses. This reduced maintenance downtime by 75% and cut replacement costs by 60%.

Estudo de caso 2: Durabilidade do rolamento do motor elétrico

A manufacturer of large industrial motors noticed bearings failing after 10,000 horas de uso (due to high heat). They switched to EN 100CrMo7 bearings, which benefit from molybdenum’s high-temperature strength. Pós-troca, bearing life increased to 25,000 horas, and the company saved $200,000 annually in maintenance costs.

5. EN 100CrMo7 vs. Outros materiais de rolamento

How does EN 100CrMo7 compare to other common bearing steels and materials? The table below breaks down the key differences:

Yigu Technology’s Perspective on EN 100CrMo7

Na tecnologia Yigu, EN 100CrMo7 is our top choice for clients in mining, heavy automotive, e máquinas industriais. Its molybdenum addition gives it unmatched fatigue resistance and high-temperature performance—critical for harsh environments. We pair it with precision forging and nitriding to maximize durability, delivering parts that last 2–3x longer than standard 100Cr6. For clients needing reliable, low-maintenance bearings, EN 100CrMo7 is a cost-effective solution that minimizes downtime and replacement costs.

FAQ About EN 100CrMo7 Bearing Steel

1. Why is molybdenum added to EN 100CrMo7?

Molybdenum improves EN 100CrMo7’s high-temperature strength and toughness, making it suitable for applications like mining equipment and industrial motors that generate heat or face heavy impacts.

2. Can EN 100CrMo7 be used in corrosive environments?

It has moderate corrosion resistance. For wet or corrosive environments (por exemplo, processamento marinho ou de alimentos), apply a surface treatment like nitriding or zinc plating to prevent rust and extend service life.

3. How does EN 100CrMo7 compare to 100Cr6?

EN 100CrMo7 has added molybdenum, which boosts fatigue resistance and high-temperature strength. It’s better for heavy-duty, aplicações de alto estresse (mineração, heavy trucks), while 100Cr6 is ideal for lighter-duty uses (light machinery, motores pequenos).