Carbon Equivalent Calculator
Determine steel weldability using AWS, IIW, and JWES carbon equivalent formulas
Steel Alloy Composition (Weight %)
Typical range: 0.05% - 1.5% for structural steels
Typical range: 0.3% - 2.0% for carbon steels
Typical range: 0.1% - 0.8% for structural steels
0% for carbon steels, up to 30% for stainless steels
0% for carbon steels, up to 1% for alloy steels
Typically 0% - 0.2% for high-strength steels
Typically 0% - 0.5% for weathering steels
0% for carbon steels, up to 12% for stainless steels
Micro-alloying element: typically 0.001% - 0.005%
Carbon Equivalent Results
⚠️ Metallurgical Safety Warning
• This calculator is for estimation purposes only
• Always consult certified welding engineers for critical applications
• Follow applicable welding codes (AWS D1.1, ASME, etc.)
• Verify actual steel chemistry through certified mill test certificates
• Consider heat treatment, cooling rate, and welding procedure effects
Example Calculation: AISI 1018 Steel
Steel Composition
IIW Calculation
CE = C + Mn/6 + (Cr+Mo+V)/5 + (Cu+Ni)/15
CE = 0.20 + 0.90/6 + 0/5 + 0/15
CE = 0.20 + 0.15 + 0 + 0 = 0.35%
Result: Excellent weldability (CE ≤ 0.35%)
IIW Weldability Ratings
Formula Comparison
AWS (American Welding Society)
Includes silicon contribution to hardenability
IIW (International Institute of Welding)
Most widely used, excludes silicon
JWES (Japan Welding Engineering Society)
Pcm parameter for crack susceptibility
Common Steel CE Values
Understanding Carbon Equivalent in Steel Welding
What is Carbon Equivalent?
Carbon equivalent (CE) is a way to understand how different alloying elements in steel affect its weldability. It converts the effect of various elements to an equivalent amount of carbon, since carbon's influence on steel properties is well understood.
Why CE Matters for Welding
- •Predicts susceptibility to hydrogen-induced cold cracking
- •Determines preheating requirements
- •Guides welding procedure qualification
- •Helps select appropriate filler metals
Element Effects on Steel
Hardening Elements
Carbon, manganese, chromium, molybdenum, vanadium increase hardenability and reduce weldability.
Crack Susceptibility
Higher CE values increase the risk of hydrogen-induced cracking in the heat-affected zone (HAZ).
Cooling Rate Effects
High CE steels form martensite during rapid cooling, creating brittle, crack-susceptible microstructures.
Professional Welding Required: This calculator provides estimates only. Always consult certified welding engineers for critical structural applications.