EN24 (817M40) — Alloy Steel Grade Specification, Properties & Equivalents
EN24 (817M40) is a high-strength, versatile alloy steel widely used in demanding Indian industrial applications. Known for its excellent combination of toughness, ductility, and wear resistance, EN24 (817M40) finds favour with manufacturers across automotive, oil & gas, and heavy
EN24 (817M40) is a high-strength, versatile alloy steel widely used in demanding Indian industrial applications. Known for its excellent combination of toughness, ductility, and wear resistance, EN24 (817M40) finds favour with manufacturers across automotive, oil & gas, and heavy machinery sectors. This grade responds well to heat treatment, allowing for tailored mechanical properties to meet specific performance requirements. Procurement engineers and fabricators in India rely on EN24 (817M40) for critical components requiring high tensile strength and reliable service life under stress. Its widespread availability from major Indian steel producers ensures a consistent supply chain for diverse manufacturing needs, making EN24 (817M40) a cornerstone material for robust engineering solutions.
Chemical Composition of EN24 (817M40)
EN24 (817M40) Chemical Composition
| Element | EN24 (817M40) % |
| Carbon (C) | 0.35 - 0.45 |
| Silicon (Si) | 0.10 - 0.35 |
| Manganese (Mn) | 0.45 - 0.70 |
| Phosphorus (P) | Max 0.035 |
| Sulphur (S) | Max 0.040 |
| Chromium (Cr) | 0.90 - 1.50 |
| Molybdenum (Mo) | 0.25 - 0.40 |
| Nickel (Ni) | 1.30 - 1.80 |
| (As received condition, typically normalized) |
Mechanical Properties of EN24 (817M40)
EN24 (817M40) Mechanical Properties (Typical values for hardened and tempered condition)
| Property | EN24 (817M40) Value |
| Ultimate Tensile Strength (UTS) | 900 - 1100 MPa |
| Yield Strength (YS) | 750 - 850 MPa |
| Elongation at Break | 12 - 18 % |
| Impact Strength (Charpy V-notch) | 60 - 80 J |
| Hardness (Brinell) | 270 - 330 HB |
| Density | 7.85 g/cm³ |
| Modulus of Elasticity | 190 - 210 GPa |
EN24 (817M40) Available Forms in India
| Shape | Typical Sizes | Standard Length |
| Round Bars | 15 mm - 250 mm Diameter | 6.0 mtr |
| Square Bars | 20 mm x 20 mm to 100 mm x 100 mm | 6.0 mtr |
| Forged Blocks | Customizable | As required |
| Sheet/Plates | 3 mm - 25 mm Thickness | Standard sheets |
EN24 (817M40) Real-world Applications
- Automotive Industry: Crankshafts, gears, drive shafts, connecting rods.
- Oil & Gas: Downhole drilling tools, valve components, high-pressure fittings.
- Heavy Machinery: Axles, heavy-duty gears, high-strength bolts, specialized shafts.
- Aerospace: Landing gear components, structural parts requiring high fatigue strength.
- Mining Equipment: Wear-resistant parts, shafts, and high-stress components.
- Defense: Critical components in armored vehicles and weaponry.
- General Engineering: High-performance pins, studs, and couplings.
- Tooling: Mandrels and forming tools requiring good toughness.
EN24 (817M40) Machinability & Weldability
EN24 (817M40) alloy steel offers moderate machinability in its annealed or normalized condition, becoming more difficult after hardening and tempering. For optimal machining, it is recommended to work with EN24 (817M40) in the softer states. Using carbide or high-speed steel tooling with slower cutting speeds and ample lubrication is advised. Typical machining operations for EN24 (817M40) include turning, milling, drilling, and tapping. When considering welding EN24 (817M40), pre-heating to 200-300°C is crucial to prevent cracking, especially in thicker sections. Low-hydrogen electrodes (e.g., E7018, E8018) are recommended. Post-weld heat treatment (PWHT), typically a stress-relieving anneal at 550-650°C, followed by slow cooling, is essential for EN24 (817M40) to reduce residual stresses and recover toughness adjacent to the weld. Ensuring proper joint preparation and interpass temperature control is vital for successful welding of EN24 (817M40).
EN24 (817M40) Heat Treatment & Processing
EN24 (817M40) alloy steel exhibits excellent response to heat treatment, allowing for a wide range of mechanical properties. Typically supplied in the normalized condition (around 850°C followed by air cooling), it can be further hardened by austenitizing at 820-850°C and quenching in oil or water, depending on the section size and desired hardness. Tempering EN24 (817M40) is critical for achieving optimal toughness and ductility; temperatures typically range from 500°C to 650°C, with lower temperatures yielding higher strength and hardness but reduced ductility. For example, tempering at 550°C might yield around 900-1000 MPa UTS, while tempering at 630°C could result in 750-850 MPa UTS with improved toughness. Annealing EN24 (817M40) at 800-850°C followed by slow furnace cooling provides maximum softness for machining. Normalizing at 840-870°C refines the grain structure and improves uniformity before subsequent hardening. Understanding the precise heat treatment parameters for EN24 (817M40) is key to unlocking its full potential for specific applications.
Sourcing EN24 (817M40) in India
EN24 (817M40) steel is readily available across India from major producers like SAIL, JSW Steel, and Jindal Stainless, as well as numerous smaller specialized mills and stockists. Key consumption and distribution hubs include Mumbai and Pune, with significant availability also in Chennai and other industrial centers. Minimum Order Quantities (MOQs) for readily stocked sizes like round bars (e.g., 50mm to 150mm) can be as low as 1-2 metric tons, while larger or custom-profiled EN24 (817M40) requirements may necessitate higher MOQs. The price band for EN24 (817M40) typically ranges from INR 150/kg to INR 220/kg, varying significantly with international nickel and chromium prices, order volume, and specific mill source. Reputable suppliers will provide Mill Test Certificates (MTC) confirming chemistry and mechanical properties as per the relevant IS or ASTM standards for EN24 (817M40).
EN24 (817M40) International Equivalents
| Standard | Code |
| BS | 817M40 |
| EN | 40CrMoV2-1 (approximate) |
| ASTM | 4140 / 4142 (similar, but EN24 has higher Ni content) |
| JIS | SCM440 (similar, but EN24 has higher Ni content) |
| DIN | 41CrMo4 (similar, but EN24 has higher Ni content) |
| GOST | 40Kh (similar, but EN24 has higher Ni content) |
FAQs about EN24 (817M40)
What is the primary advantage of using EN24 (817M40) steel?
The primary advantage of EN24 (817M40) steel lies in its exceptional balance of high tensile strength, toughness, and wear resistance, particularly after heat treatment. This makes EN24 (817M40) ideal for components subjected to severe stress, shock, and fatigue, offering reliable performance in demanding engineering applications across various Indian industries.
Can EN24 (817M40) be welded easily?
Welding EN24 (817M40) requires careful procedures. Preheating to 200-300°C and using low-hydrogen electrodes are essential to prevent cracking. Post-weld heat treatment, such as a stress-relieving anneal, is critical for EN24 (817M40) to restore its mechanical properties near the weld zone and reduce residual stresses. Proper execution ensures the integrity of welded EN24 (817M40) components.
What is the typical heat treatment for EN24 (817M40) steel for maximum strength?
For maximum strength in EN24 (817M40) steel, a typical heat treatment involves hardening by austenitizing at 820-850°C followed by quenching in oil. Subsequently, tempering at a lower temperature, generally between 500°C and 550°C, is performed. This process yields high tensile and yield strengths for EN24 (817M40), albeit with slightly reduced toughness compared to higher tempering temperatures.
Where is EN24 (817M40) commonly used in India by manufacturers?
Manufacturers in India extensively use EN24 (817M40) for critical automotive parts like crankshafts and gears, heavy machinery components such as axles and high-stress shafts, and oil & gas exploration tools. Its high strength-to-weight ratio and durability make EN24 (817M40) a preferred choice for applications demanding robust performance and longevity.
What is the difference between EN24 (817M40) and AISI 4140 steel?
While both EN24 (817M40) and AISI 4140 are medium carbon alloy steels used for high-strength applications, EN24 (817M40) typically contains a higher percentage of Nickel (1.30-1.80%) compared to 4140. This higher nickel content in EN24 (817M40) generally imparts improved toughness and hardenability, making it a premium choice for more severe service conditions.
What MTC should I expect when sourcing EN24 (817M40) in India?
When sourcing EN24 (817M40) in India, you should expect a Mill Test Certificate (MTC) that details the specific heat batch's chemical composition, including percentages of Carbon, Manganese, Chromium, Molybdenum, and Nickel. The MTC for EN24 (817M40) will also confirm mechanical properties such as Ultimate Tensile Strength (UTS), Yield Strength (YS), Elongation, and Hardness, typically tested as per relevant IS or ASTM standards.
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