Carbon level
The carbon level indicates how much carbon is dissolved in an iron melt. A high carbon level increases the hardness and strength of the steel but can lead to hot cracking.
Physical-Chemical Mechanism
The carbon level in the furnace atmosphere determines how much carbon dissolves in the iron melt. Carbon dissolves in the liquid melt, forming molecules with the iron. This process affects the chemical composition of the steel.
Metallurgical Relevance & Welding Risks
A high carbon level increases hardness and strength, which can be useful for special applications. However, too high a carbon content leads to an increased risk of hot cracks and fusion cracks in the weld. A low carbon level, on the other hand, can reduce hardness, which can be helpful for better formability.
Workshop Practice & Actions
To achieve the desired carbon level, the right carbon source material must be added to the furnace atmosphere. This can be done, for example, by using coal or gas as fuel. Temperature and duration of the melting process must also be precisely controlled to achieve the desired carbon level. A carbon level between 0.2% and 1.5% is generally suitable for most steel types.