Enter your steel's elemental composition — C, Mn, Si, Cr, Mo, V, Cu, and Ni percentages — into the Carbon Equivalent Calculator to get your material's CE value, a Weldability Rating, and whether preheating is recommended before welding.
Carbon Equivalent (CE)
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Weldability Rating
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Preheating Required
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AISI 1018 steel typically has a carbon equivalent of approximately 0.27-0.32% using the AWS formula. This relatively low CE indicates good weldability without preheating requirements.
Steel with a CE of 0.40% has fair to poor weldability. This level typically requires preheating before welding to prevent cracking and may need controlled cooling rates after welding.
Preheating is generally recommended when the carbon equivalent exceeds 0.35-0.40%. Above 0.45% CE, preheating becomes essential to prevent hydrogen cracking and ensure weld quality.
Higher hardenability typically means lower weldability. As carbon equivalent increases, the steel becomes more prone to forming hard, brittle zones in the heat-affected zone during welding, making it more difficult to weld.
The AWS formula is more commonly used in North America and includes all major alloying elements. The IIW formula is widely used internationally and focuses on the most critical elements for weldability assessment.
Higher CE values require more careful welding procedures including preheating, controlled heat input, post-weld heat treatment, and sometimes special electrodes to prevent cracking and achieve desired mechanical properties.
Low carbon steels: 0.20-0.35% CE (excellent weldability), medium carbon steels: 0.35-0.50% CE (fair weldability), high carbon steels: >0.50% CE (poor weldability, requires special procedures).