Equivalent Carbon (CE) and how the calculator determines C% and Si%
Two organizations can report the same carbon percentage, and carbon equivalents explain why.
Equivalent carbon (CE) is a composite index representing the combined effect of carbon and other elements on the melting point of cast iron. Two heats with the same C% but different Si% will have different CE values, resulting in different microstructures after cooling.
The thermal analyzer does not directly measure C% and Si%. It records the sample's cooling curve, identifies phase transition points, derives CE, and then calculates C% and Si% based on the manufacturer's calibration model.
Key Control Points
CE Formula
The common formula is CE = C% + Si%/3 (+ P%/3 depending on the document), used to evaluate overall graphitization potential.
Why CE is required
CE helps compare batches with different compositions but the same degree of graphitization.
How the machine infers
Cooling curve for crystallization temperature; calculate CE, then derive C% using the calibration relationship.
Limit
Results depend on the sample and cup; if the sample is not representative, CE calculations will be incorrect even with a properly functioning device.
Real-world experience
- Do not compare CE between different iron types; only compare within the same product line.
- Recheck the calibration formula when changing cup type or supplier.
- Record both CE and C% on the batch sheet for future context.
Compatible device
CYY-LK2 Pre-furnace Rapid Carbon-Silicon Analyzer
Carbon-Silicon Analyzer CYY-LK2 — Analyze C and Si in molten iron before the furnace. CE certified, English interface.
Reference price: 700-800 USD
CYY-LK7 Molten Iron Thermal Analyzer for Foundries
Liquid Iron Thermal Analyzer CYY-LK7 — analyzes cooling curve, measures CEL, C%, Si%, Mn%, and spheroidization ratio. CE certified with 15-inch TFT display.
Reference price: 1700-1900 USD
CYY-CE Carbon-Silicon Analyzer Sample Cup — CYY-CE1/CE2/CE3 Tellurium Insulated Probe Cup
CYY-CE1/CE2/CE3 Tellurium Sampling Cup for Carbon Silicon Analyzer CYY-LK2/LK7. Essential consumables for iron casting workshops.
Reference price: 0.5-1.5 USD
Frequently Asked Questions
Does CE cao mean high carbon?
Not necessarily. Since CE includes silicon, a high CE value could result from a high Si% rather than a high C%.
Does the machine automatically calculate CE?
Yes, most thermal analyzers display CE along with C% and Si% after each measurement.
Related topics
- Compare methods for checking CE and C% before the furnace
- What is a liquid iron analyzer and what does it measure?
Reference content from Changyouyi's technical article: original post on Sohu.
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