C40E Alloy Steel Bar C40E Round Bars C40E Rods

Product Description

C40E (1.1186) Carbon Steel Overview

C40E is a non-alloy medium-carbon engineering steel categorized under the EN 10083-2 standard. It is a "special" quality steel, meaning it has closely controlled chemical composition and higher purity levels (specifically lower sulfur and phosphorus content) compared to standard C40. This makes it particularly suitable for induction hardening and heavy-duty forging.

Chemical Composition (Typical %)

Mechanical Properties (Quenched & Tempered)

The properties of C40E vary based on the diameter of the round bar or the thickness of the rod. For a standard diameter of $16 < d \le 40$ mm:

• Tensile Strength ($R_m$): 580 – 730 MPa

• Yield Strength ($R_e$): $\ge$ 380 MPa

• Elongation ($A$): $\ge$ 18%

• Impact Energy (KV): $\ge$ 35 J (at 20°C)

International Comparison & Equivalents

C40E is the European designation, but it aligns closely with other international standards for medium-carbon steel:

Key Characteristics

1. Hardenability: Due to the "E" suffix (indicating controlled purity), C40E exhibits consistent results during heat treatment. It can reach a surface hardness of approximately 50–55 HRC after induction or flame hardening.

2. Machinability: In the normalized or annealed condition, it offers good machinability, similar to AISI 1040.

3. Weldability: Limited. Due to the carbon content, preheating and post-weld heat treatment are generally required to prevent cold cracking.

Common Applications

• Round Bars: Extensively used for shafts, axles, crankshafts, and connecting rods.

• Rods: Utilized in the production of high-strength bolts, studs, and forged components.

• General Engineering: Components that require higher strength than mild steel but do not justify the cost of high-alloy steels (like Chrome-Moly).

Processing Temperatures

• Hot Forming: 850°C – 1100°C

• Normalizing: 850°C – 880°C

• Hardening: 830°C – 870°C (Water or Oil quench)

• Tempering: 550°C – 660°C