1. Designation and Standard

• Basic Overview

• Name: 20MnCrS5

• Standards:

European Standard: EN 10084 (Case hardening steels)

German Equivalent: DIN 1.7147

Comparable Chinese Grade: 20MnCr5 (but with higher sulfur content)

• Type:

Low-carbon alloy case hardening steel, specifically designed to enhance surface hardness and core toughness. Ideal for wear-resistant and fatigue-resistant components such as gears and shafts.

2. Chemical Composition

C：≤ 0.22%

Si：≤ 0.40%

Mn：1.10 – 1.50

P：≤ 0.035%

S：0.010 – 0.040

Cr：1.00 – 1.30

3. Mechanical Properties (after appropriate heat treatment)

• Tensile Strength (σb): ~1482 MPa — High strength for demanding applications.

• Yield Strength (σ0.2): ~1232 MPa — High resistance to plastic deformation.

• Elongation (δ5): 13% — Moderate ductility for forming and shaping.

• Reduction of Area (ψ): 57% — Indicates excellent plasticity during fracture.

• Impact Toughness (αku): 73 J/cm² — Good toughness under impact loads.

• Hardness: ~357 HB — High surface hardness for wear resistance.

4. Key Characteristics

• High Strength: Optimized alloying and heat treatment deliver superior load-bearing capacity.

• Excellent Wear Resistance: Chromium contributes to long-lasting durability in abrasive environments.

• Good Toughness: Maintains structural integrity under complex and cyclic loading, resisting brittle failure.

• Enhanced Machinability: Sulfur improves chip formation and tool life, ensuring high surface finish quality.

• Moderate Weldability: Suitable for fusion and friction welding, with recommended preheating and post-weld treatment to avoid cracking.

5. Heat Treatment Processes

Carburizing: Performed at 900–950°C, this process diffuses carbon into the surface, increasing surface hardness.

Quenching: Converts the carburized layer into hard martensitic microstructure for strength and wear resistance.

Tempering: Reduces brittleness and enhances toughness, optimizing the steel’s overall mechanical balance.

6. Typical Applications

20MnCrS5 is widely used in:

• Transmission Gears: In automotive and industrial machinery for reliable power delivery under load.

• Bearings: Withstand both radial and axial loads with high hardness and minimal wear.

• Guide Rails: Ensures smooth, accurate movement in machine tools and automation equipment.

• Other Components:

Shafts, cams, and rollers

Connecting rods under dynamic loading

Gears in non-impact pumps

Rotors, clutches, and pressure vessel bolts

7. Processing Notes

Forging: Requires careful control of heating temperature, pressure, and deformation ratio to avoid overheating or burning.

Rolling: Suitable for certain dimensions; temperature and reduction must be tightly controlled to ensure dimensional accuracy.

Machining: After heat treatment, higher hardness makes machining more challenging. Use carbide tools, lower cutting speeds, and higher feed rates.

Surface Treatment: Depending on end use, optional treatments like shot peening, sandblasting, electroplating, or coating can improve surface quality and resistance.

8. Summary

With its outstanding tensile strength, wear resistance, toughness, and machinability, 20MnCrS5 stands out as a representative material among case-hardened structural steels. Its ability to perform reliably under severe operating conditions and its adaptability to precision processing make it ideal for critical transmission components. Whether in high-speed gear systems or finely machined shafts, 20MnCrS5 delivers both performance and productivity.

9. About Suzhou Bolaibao Metal

At Shanghai Bolaisheng Metal, we provide long-term, stable supply of premium 20MnCrS5 alloy steel, backed by expert material selection support and customized processing solutions. With years of experience in the metal industry, we are committed to helping customers in automotive, aerospace, and machinery sectors achieve high-performance results with greater processing efficiency.

Contact us today for technical datasheets, samples, or application advice!

• Tel: +86 15366282159

• Email: sale@bolaibao1.com

• Website: www.blbszmetal.com