EN Series

EN32B

Introduction:

EN32B is a carbon case hardening steel known for its ability to develop a hard, wear-resistant surface (case) while maintaining a tough and ductile core. This makes it ideal for components requiring surface hardness to resist wear and a core capable of absorbing impact. It is commonly supplied in the bright drawn or turned bar condition and is characterized by good machinability and weldability.

Properties of the Grade:

  • Machinability: Good machinability in its supplied condition.
  • Weldability: Excellent weldability, suitable for various welding techniques.
  • Hardenability: Limited hardenability; primarily hardened through case hardening processes.
  • Toughness: Tough core after case hardening, providing resistance to impact.

Standards and Equivalent Grades:

  • BS 970: 1955: EN32B
  • BS 970: 1991: 080A15
  • DIN: C15
  • AISI/SAE: 1015, 1016, 1018
  • IS: C14, C15Mn75
  • Wnr: 1.1141

Chemical Composition (wt. %):

Element Content (%)
Carbon (C) 0.13 – 0.18
Silicon (Si) 0.10 – 0.40
Manganese (Mn) 0.70 – 0.90
Phosphorus (P) ≤0.05
Sulfur (S) ≤0.05

Forging:

  • Forging Temperature: 850 – 1200°C
  • Cool slowly after forging.

Dimensional Tolerances:

  • Bright/Black: Best H11
  • Hot Rolled Round Bar: -0/+1 mm
  • Peeled/Ground: Best H11
  • Hot Forged Round Bar: -0/+5 mm
  • Rough Turned: -0/+3 mm

Machinability:

  • Good machinability in annealed condition.

Available Forms:

  • Round Bar
  • Flat Bar
  • Square Bar

Uses/Applications of the Grade:

EN32B is commonly used for lightly stressed components that require a hard-wearing surface and a tough core. Typical applications include:

  • Gears
  • Cams
  • Rollers
  • Bushes
  • Spindles
  • Collets

Mechanical Properties (Typical):

Property Value
Tensile Strength (Rm) 430 – 490 N/mm²
Elongation (A₅) 16 – 18%
Impact Strength (Izod) 30 J

Physical Properties (Typical):

  • Density: 7.85 g/cm³
  • Melting Point: 1420 – 1460°C
  • Thermal Conductivity: 50 W/m.K

Heat Treatment:

  • Annealing: Heat to 680 – 710°C, hold, then cool in the furnace.
  • Hardening: Heat to 780 – 820°C, quench in oil.
  • Tempering: Heat to 150 – 200°C and cool in air.
  • Case Hardening: Carburize at 880 – 920°C, quench in oil or water.

Corrosion Resistance:

  • Limited corrosion resistance; protective coating recommended.

Weldability:

  • Good weldability, preheating recommended for thicker sections.

Conclusion:

EN32B carbon steel is a versatile material that offers a combination of surface hardness and core toughness. It is ideal for applications where wear resistance is crucial, while maintaining the ability to absorb shock and impact. Its good machinability and weldability make it easy to work with, making it suitable for a range of engineering applications.