20Mn2 carbon–manganese steel

Introduction

We manufacture forging ingots, billets, and blooms in carbon–manganese steel specifically for 20 mn2, designed for medium strength engineering applications where good toughness, hardenability, and reliable mechanical performance are required.

20Mn2 is a low carbon, high manganese engineering steel that offers improved hardenability and toughness compared to plain carbon steels of similar carbon content. The elevated manganese level enhances strength and fatigue resistance, making this grade suitable for dynamic and load-bearing components in automotive and general engineering applications.

Chemical composition

Element Content (%) Function / effect
Carbon (c) 0.16 – 0.24 Provides moderate strength with good toughness
Manganese (mn) 1.30 – 1.70 Significantly improves hardenability, strength, and toughness
Sulfur (s) 0.050 max Improves machinability; controlled to avoid brittleness
Phosphorus (p) 0.050 max Limited to maintain toughness
Silicon (si) 0.10 – 0.35 Acts as deoxidizer and improves strength
Chromium (cr) Nil Not intentionally added
Nickel (ni) Nil Not present
Molybdenum (mo) Nil Not present
Other elements No significant alloying additions

Mechanical properties (typical values, dependent on heat treatment and section size)

  • Tensile strength: Approx. 520 – 650 MPa
  • Yield strength: Approx. 300 – 420 MPa
  • Elongation: Approx. 18 – 22%
  • Hardness (normalized): Approx. 150 – 190 HB
  • Impact toughness: Good
  • Fatigue resistance: Good

Heat treatment

  • annealing: improves machinability and relieves internal stresses
  • normalizing: refines grain structure and improves strength and toughness
  • quenching: increases strength and hardness
  • tempering: balances hardness with toughness
  • 20Mn2is suitable for through hardening for moderate load applications

Key features and benefits

  • higher hardenability due to increased manganese
  • good strength and toughness balance
  • excellent fatigue and shock resistance
  • good machinability in annealed condition
  • uniform mechanical properties
  • cost-effective carbon–manganese steel

Typical applications

  • shafts and axles
  • automotive and tractor components
  • forged engineering parts
  • pins, bolts, and connecting parts
  • general machinery components

Equivalent steel grades

  • 20Mn2(is)
  • en 15 (approximate)
  • aisi 1522 (approximate)
  • din 1.1179
  • jis s20mn

Why choose 20Mn2for your application?

20Mn2is the ideal choice when better hardenability and toughness are required than standard low carbon steels. Its high manganese content provides improved mechanical performance, making it suitable for dynamic and load-bearing engineering applications.

Comparison table for similar grades

Grade Carbon (%) Key applications Heat treatment Comments
20 mn2 0.16 – 0.24 Shafts, forgings, auto parts Normalizing / q&t High manganese, good hardenability
C 20 0.17 – 0.23 General engineering Normalizing Lower hardenability
En 15 0.30 – 0.40 Engineering parts Normalizing Higher carbon
Aisi 1522 0.19 – 0.25 Automotive components Q&t American equivalent

Summary

20Mn2is a low carbon, high manganese engineering steel offering good strength, toughness, and fatigue resistance. With its excellent response to heat treatment and cost-effectiveness, it is widely used in automotive and general engineering components.