Carburizing Carbon Potential
The carbon potential determines how much carbon is transferred from the furnace atmosphere to the parts. It controls the maximum carbon concentration at the surface before quenching.
Physical-Chemical Mechanism of Action
The carburizing potential is a measure of the ability of the furnace atmosphere to transfer carbon to the parts. It depends on the gas compositions and temperatures in the furnace.
Metallurgical Relevance & Risks in Welding
Too high a carburizing potential can lead to an excessively high surface carbon concentration, which can cause hot cracking and low toughness of the weld. Too low a carburizing potential prevents sufficient carbon transfer, which can lead to a lack of structure and poorer mechanical properties.
Workshop Practice & Instructions
To control the carburizing potential, the furnace gas compositions and temperatures must be precisely set. A typical carbon concentration in the furnace atmosphere is about 50 ppm. For heavy steels such as martensite or ferrite, the carburizing potential should be set so that the maximum surface carbon concentration is between 0.1% and 0.2%.