En18C alloy steel

Introduction

We manufacture forging ingots, billets, and blooms in alloy steel specifically for En18C, developed for high-strength engineering and automotive applications requiring improved toughness and cleanliness.

En18C is a medium carbon chromium alloy steel, similar in chemistry to En18, but supplied with controlled sulphur content to enhance machinability. It offers high tensile strength, good toughness, and excellent wear resistance after heat treatment.

The chromium content improves hardenability and wear resistance, enabling effective through hardening. En18C provides better machinability than standard En18 while maintaining good dimensional stability after heat treatment, making it suitable for forging and precision machining operations.

This grade delivers a reliable balance of strength, machinability, and durability for demanding industrial applications.

Chemical composition

Element Content (%) Function / effect
Carbon (c) 0.35 – 0.45 Provides strength and hardness
Manganese (mn) 0.60 – 0.90 Improves hardenability and toughness
Silicon (si) 0.15 – 0.35 Enhances strength and elasticity
Chromium (cr) 0.90 – 1.20 Increases hardness and wear resistance
Sulphur (s) 0.040 – 0.070 Improves machinability
Phosphorus (p) Max 0.035 Controlled impurity

Mechanical properties (typical, depending on condition & heat treatment)

  • Tensile strength: 800 – 950 MPa
  • Yield strength: 600 – 750 MPa
  • Hardness: 26 – 32 hrc
  • Impact toughness: moderate to good
  • Fatigue resistance: good

Heat treatment

  • Annealing: used to soften the steel and improve machinability before final processing.
  • Quenching: heating to approximately 830 – 860°c, followed by rapid cooling to achieve a hardened structure.
  • Tempering: performed to relieve internal stresses and improve toughness while retaining required hardness.

Heat treatment cycles can be adjusted to balance machinability, strength, and toughness as per application requirements.

Key features and benefits

  • Improved machinability compared to En18
  • Good through-hardening capability
  • High strength with adequate toughness
  • Good wear resistance
  • Dimensional stability after heat treatment
  • Suitable for forging and machining

Typical applications

  • Machined shafts and spindles
  • Gears and pinions
  • Studs, bolts, and fasteners
  • Automotive and general engineering components
  • Parts requiring extensive machining

Equivalent steel grades

En18C is comparable to the following grades:

  • 41Cr4s (free-machining variant)
  • Din 1.7035 with controlled sulphur
  • AISI / SAE 5140 (modified)

(exact equivalence depends on sulphur control and supply condition.)

Why choose En18C alloy steel?

En18C is ideal for components requiring good mechanical strength along with improved machinability. It reduces machining time and tool wear while delivering reliable performance in medium to high-stress applications.

Comparison table for similar grades

Grade Carbon (%) Key applications Heat treatment Comments
En18C 0.35 – 0.45 Machined shafts, gears Quenching & tempering Better machinability
En18 0.35 – 0.45 General engineering Q&t Standard grade
41Cr4 0.38 – 0.45 Automotive components Q&t Close equivalent
En19 0.38 – 0.45 Heavy-duty parts Q&t Higher strength

Summary

En18C is a machinability-enhanced chromium alloy steel offering good strength, wear resistance, and dimensional stability. It is widely used in automotive and engineering applications where machining efficiency is critical.