Se você precisa de um aço para ferramentas acessível que equilibre a usinabilidade, dureza, eoil hardening characteristics for mid-low load cold working—L6 oil hardening tool steel é a escolha perfeita. Amplamente utilizado em ferramentas de corte e pequenas matrizes de estampagem, esta liga resolve pontos problemáticos comuns, como altos custos de produção ou empenamento devido à têmpera com água. Neste guia, vamos detalhar suas principais propriedades, usos no mundo real, etapas de fabricação, and how it compares to other materials—so you can build reliable tools without overspending.
1. Material Properties of L6 Oil Hardening Tool Steel
L6’s appeal lies in its simple yet effective composition, which delivers essential cold working performance at a low cost. Let’s explore its properties in detail:
1.1 Composição Química
The elements in L6 work together to enhance hardness, usinabilidade, and oil hardenability—tailored for budget-friendly tooling. Below is its standard composition (per AISI standards):
| Element | Content Range (%) | Key Role |
|---|---|---|
| Carbon (C) | 0.60 – 0.70 | Provides sufficient hardness for cutting tools while keeping machinability high. |
| Manganese (Mn) | 0.70 – 1.00 | Melhoraoil hardening characteristics and reduces brittleness during quenching. |
| Silício (E) | 0.20 – 0.35 | Enhances strength and resistance to oxidation in cold working environments. |
| Chromium (Cr) | 0.60 – 0.90 | Boosts wear resistance and hardenability; supports uniform oil quenching. |
| Níquel (Em) | 0.50 – 0.80 | Enhances toughness and ductility—prevents tool chipping in light impact tasks. |
| Molybdenum (Mo) | ≤ 0.25 | A trace element that slightly improves hardenability (kept low for cost control). |
| Vanadium (V) | ≤ 0.10 | A minor additive that refines grain structure (minimized to reduce costs). |
| Sulfur (S) | ≤ 0.030 | Minimized to avoid weakening the steel and reducing fatigue strength. |
| Phosphorus (P) | ≤ 0.030 | Kept low to prevent brittleness, especially in cold stress conditions. |
1.2 Propriedades Físicas
These properties determine how L6 behaves during manufacturing and use—such as heat transfer and shape retention. All values are measured at room temperature unless noted:
- Densidade: 7.85 g/cm³ (consistent with most carbon/alloy steels, simplifying tool weight calculations).
- Ponto de fusão: 1450 – 1500 °C (high enough to withstand forging and heat treatment without deformation).
- Condutividade Térmica: 29 C/(m·K) (good heat transfer, helping dissipate friction heat during cutting or stamping).
- Coeficiente de Expansão Térmica: 12.1 × 10⁻⁶/°C (de 20 para 600 °C; low enough to minimize warping during oil quenching).
- Capacidade Específica de Calor: 465 J/(kg·K) (efficient at absorbing heat, useful for controlled tempering).
1.3 Propriedades Mecânicas
L6’s mechanical properties are optimized for mid-low load cold working—prioritizing a balance of hardness and machinability. Below are typical values after standard oil quenching + têmpera:
| Propriedade | Valor típico | Test Standard | Why It Matters |
|---|---|---|---|
| Dureza (CDH) | 55 – 58 | ASTM E18 | Sufficient hardness forferramentas de corte and light stamping dies; avoids excessive brittleness. |
| Resistência à tracção | ≥ 1700 MPa | ASTM A370 | Handles light to moderate cold working forces (por exemplo, shearing thin metal sheets). |
| Yield Strength | ≥ 1500 MPa | ASTM A370 | Resists permanent deformation, keeping tools dimensionally stable for 100,000+ ciclos. |
| Alongamento | ≥ 8% | ASTM A370 | Moderate ductility, reducing chipping risk in light impact tasks. |
| Impact Toughness (Entalhe em V Charpy) | ≥ 25 J. (no 20 °C) | ASTM A370 | Fair toughness—suitable for non-heavy impact tools likealargadores or small punches. |
| Fatigue Strength | ~700 MPa (10⁷ cycles) | ASTM E466 | Resists wear from repeated use (key for low-volume to mid-volume production tools). |
1.4 Other Properties
- Resistência à corrosão: Moderado. Chromium content provides basic rust protection in dry workshops; avoid prolonged moisture exposure.
- Resistência ao desgaste: Bom. Suitable for cutting soft-to-moderate hardness materials (por exemplo, alumínio, aço macio); not ideal for hard metals (HRC > 30).
- Usinabilidade: Excelente. Low alloy content and moderate hardness (when annealed to HRC 20–25) make it easy to mill, furar, and turn—machining time is 20–30% less than high-alloy tool steels.
- Hardenability: Bom. Oil quenching ensures uniform hardening for tools up to 25 mm de espessura; thicker tools may need slower quenching to avoid soft cores.
- Oil Hardening Characteristics: Outstanding. Oil quenching (contra. água) reduces thermal shock, minimizing warping—a major advantage over water-hardening steels.
- Estabilidade Dimensional: Muito bom. Low thermal expansion and gentle oil quenching keep tools dimensionally consistent after heat treatment.
2. Applications of L6 Oil Hardening Tool Steel
L6’s cost-effectiveness and balanced properties make it ideal for mid-low load cold working tools. Here are its most common uses, com exemplos reais:
2.1 Ferramentas de corte
- Exemplos: Alargadores, small drills (≤ 10 mm de diâmetro), and hand-held cutting tools for machining mild steel or aluminum.
- Why it works: Good hardness keeps edges sharp, while machinability reduces tool production costs. Um EUA. small machine shop used L6 reamers for aluminum parts—tool life was 50% longer than carbon steel reamers.
2.2 Light Stamping Dies
- Exemplos: Dies for stamping thin metal sheets (≤ 2 milímetros) into parts like electrical contacts or washer blanks.
- Why it works: Oil hardening minimizes warping, ensuring die accuracy. A Chinese electronics manufacturer used L6 stamping dies—die warping dropped by 80% contra. water-hardened steel.
2.3 Cold Shearing Tools
- Exemplos: Shear blades for cutting thin metal strips (por exemplo, copper or mild steel) in low-volume production.
- Why it works: Moderate toughness prevents blade chipping, while wear resistance handles repeated cutting. A European hobby metal shop used L6 shear blades—blade life doubled vs. aço carbono.
2.4 Small Punches and Dies
- Exemplos: Punches for creating small holes (≤ 5 milímetros) in plastic or thin metal, or dies for forming small consumer product parts.
- Why it works: Dimensional stability ensures consistent hole sizes, while affordability fits low-budget projects. A Japanese toy manufacturer used L6 punches—part defect rates fell by 35%.
3. Manufacturing Techniques for L6 Oil Hardening Tool Steel
Turning L6 into usable tools is straightforward, with a focus on leveraging its oil hardening advantage. Aqui está uma análise passo a passo:
- Fusão: Raw materials are melted in an electric arc furnace (1500–1600 °C) with cost-controlled alloy addition—nickel and chromium are kept at minimum effective levels.
- Fundição: Molten steel is poured into ingot molds or continuous casters. Resfriamento lento (30–50 °C/hour) prevents internal defects.
- Forjamento: Ingots are heated to 1100–1200 °C and pressed into tool blanks (por exemplo, 100x100x50 mm for small dies). Forging improves grain structure and strength.
- Tratamento térmico: The standard cycle for L6 (optimized for oil hardening):
- Recozimento: 800–850 °C, hold 2–3 hours, slow cool. Softens steel to HRC 20–25 for machining.
- Têmpera: 820–860 °C, hold 30–60 minutes, quench in mineral oil (60–80 °C). Hardens steel to HRC 58–60.
- Temperamento: Reheat to 180–220 °C, hold 1–2 hours, cool. Reduces brittleness and sets final hardness (HRC 55–58).
- Usinagem: Most shaping (fresagem, perfuração) is done post-annealing. High-speed steel tools work well for basic cuts; carbide tools for tight tolerances (±0,01 mm).
- Moagem: After heat treatment, tools are ground to final dimensions and sharpened—critical for cutting tools like reamers.
- Tratamento de superfície (Opcional):
- Nitriding: Adds a hard surface layer (HRC 60–65) to boost wear resistance for high-use tools.
- Galvanoplastia: Chrome coating for extra corrosion resistance (por exemplo, tools used in humid environments).
4. Estudo de caso: L6 in Light Stamping Dies for Electrical Contacts
A Korean electronics component manufacturer faced a problem: their water-hardened steel dies for electrical contacts warped during quenching, leading to inconsistent contact sizes. They switched to L6, e aqui está o que aconteceu:
- Processo: Die blanks were forged, recozido (CDH 22), machined to stamping geometry, oil-quenched (840 °C), tempered (200 °C), and ground to precision.
- Resultados:
- Die warping eliminated—contact size tolerance improved from ±0.1 mm to ±0.03 mm.
- Die life increased from 50,000 para 120,000 ciclos (140% melhoria) thanks to L6’s better wear resistance.
- Tool production costs dropped by 20%—L6’s machinability reduced manufacturing time.
- Why it works: L6’s oil hardening characteristics minimized thermal shock, evitando empenamento, while chromium and nickel boosted die durability—solving both accuracy and longevity issues.
5. L6 vs. Outros materiais
How does L6 compare to common alternatives for mid-low load cold working tools? Let’s evaluate key properties:
| Material | Dureza (CDH) | Oil Hardening? | Usinabilidade | Custo (contra. L6) | Melhor para |
|---|---|---|---|---|---|
| L6 Oil Hardening Steel | 55 – 58 | Sim | Excelente | 100% | Light stamping dies, small cutting tools, low-mid volume production |
| Water Hardening Steel (W1) | 58 – 60 | Não (água) | Bom | 70% | Very simple tools (por exemplo, chisels) – high warping risk |
| Aço carbono (1095) | 55 – 60 | Não | Bom | 60% | Baixo custo, low-wear tools (por exemplo, basic punches) |
| Liga de aço (4140) | 30 – 35 | Não | Excelente | 90% | Partes estruturais (não ferramentas de corte) |
| Aço Rápido (HSS) | 60 – 65 | Não | Pobre | 300% | High-speed cutting (not cost-sensitive) |
| S7 Shock Resistant Steel | 45 – 50 | Sim | Justo | 180% | High-impact tools (out of L6’s range) |
Key takeaway: L6 offers the best cost-performance ratio for mid-low load cold working tools. It’s cheaper than HSS or S7, more durable than carbon steel, and far less prone to warping than water-hardened steel.
Yigu Technology’s View on L6 Oil Hardening Tool Steel
Na tecnologia Yigu, L6 is our top recommendation for clients needing affordable, reliable tools for low-mid load cold working—like small machine shops or low-volume manufacturers. Its oil hardening advantage solves the common issue of warping, while its machinability cuts production costs. We often suggest L6 for reamers, light stamping dies, or small punches—applications where high alloy steels would be overkill. For businesses balancing quality and budget, L6 isn’t just a material—it’s a practical, solução econômica.
FAQ About L6 Oil Hardening Tool Steel
1. Can L6 be used for machining hard metals (por exemplo, CDH 35+ aço)?
No—L6’s wear resistance is only suitable for soft-to-moderate hardness materials (≤ HRC 30). Para metais duros, choose HSS or carbide tools—L6 will wear out too quickly, increasing tool replacement costs.
2. What’s the maximum tool thickness L6 can handle with uniform oil quenching?
L6’s hardenability is best for tools up to 25 mm de espessura. For thicker tools (25–40 mm), we recommend a pre-heat step (700–750 °C for 1 hora) before quenching to ensure the core hardens evenly—this prevents soft spots.
3. Is L6 suitable for high-volume production (100,000+ peças)?
L6 works for mid-volume production (100,000–200,000 parts) for low-load tools. For high-volume (200,000+ peças), we recommend upgrading to S7 or HSS—their better wear resistance will reduce long-term tool replacement costs.