Effective Carbon Content for Welds
The effective carbon content indicates how much carbon in the weld can contribute to hardening and carbide formation. It helps predict mechanical properties.
Physical-Chemical Mechanism
The effective carbon content (ECC) considers the actual contribution of carbon and microalloying elements to hardening and carbide formation. During the welding process, carbon reacts with iron to form carbides, increasing hardness.
Metallurgical Relevance & Risks in Welding
Too high an effective carbon content can lead to excessive hardening, impairing the toughness and dimensional stability of the weld. This increases the risk of cracks and hot cracks. Conversely, too low a value can result in soft, less tough welds.
Workshop Practice & Instructions
To set the effective carbon content optimally, the carbon content in the melt and the hardness of the alloy should be considered. For stiff alloys (e.g., high-strength steels), the ECC should be kept low to ensure toughness. For soft alloys, a higher ECC may be acceptable as long as mechanical properties remain within tolerance.