Cast Iron Analysis
1. Overview
The Cast Iron Analysis Module of I-MEASURE PLUS is a metallurgical analysis tool that measures the nodularity of graphite, the number of graphite particles, and the percentage of ferrite and pearlite phases in the matrix of ductile cast iron. In addition, it provides the distribution of area ratios according to graphite shape, enabling evaluation of nodularity based on relevant standards.
2. Standards
KS D 4302: 2006
ASTM E2567
ISO 945
JIS G 5502: 2001
GB/T 9441: 1988
3. Criteria for Nodularity Evaluation
Images for nodularity evaluation are acquired at 100× magnification, with a frame size of 90 mm × 65 mm (or an equivalent area).
Graphite particles that touch the image boundary are excluded from the measurement.
Particles smaller than 20 µm are also excluded.
For cast iron products produced using molds, the lower threshold is reduced to 10 µm.
Each image must contain at least 50 graphite particles.
Nodularity is calculated as the average of results obtained from five fields of view.
4. Nodularity (Graphite %)
The module provides functions to measure Graphite %, representing the nodularity ratio.
CAST IRON ( Graphite ) 흑연구상화율 (Nodularity) 측정 대화 창
5. Evaluation Methods
ASTM A247 : Nodularity is defined as the percentage of graphite particles of types IV, V, VI (≥ 20 µm) divided by the total number of graphite particles of types I–VI. ASTM A247: Nodularity is defined as the percentage of graphite particles of types IV, V, VI (≥ 20 µm) divided by the total number of graphite particles of types I–VI.
KS D4302 / SYS-FFCA-D4302-5016 :
This evaluation method calculates the nodularity from the number of graphite particles and their shape factors, excluding graphite particles smaller than 20 µm in actual size.
| Shape Factor | 0 | 0.73 | 0.92 | 1 |
| Graphite Area Ratio (%) relative to a circle with a diameter equal to the maximum length of graphite | Less than 51% | 51% or more, less than 65% | 65% or more, less than 82% | 82% or more |
| Number of Graphite Particles | n1 | n2 | n3 | n4 |
The shape factor of graphite particles and the graphite area ratio relative to a circle with a diameter equal to the maximum length of the graphite.
The nodularity of graphite is determined based on the number of graphite particles and their shape factors according to the following equation.
| KS D 4302 / SPS-KFCA-D4302-5016 KS D 4302 was abolished in August 2014. The Korean Foundrymen’s Society (KFCA) adopted SPS-KFCA-D4302-5016 as a group standard, retaining the original KS D 4302 criteria for ductile cast iron. |
6. Graphite Detection
Users can adjust a threshold slider to detect graphite in the image. Once defined, the threshold value is maintained across analyses.
● Filter ( Remove noise ) : Removes small, unnecessary particles that are not relevant to the measuremen
● Flatten Background: Automatically corrects image distortion (brightness variation) caused by uneven illumination.
7. Measurement Procedure
Pressing the MEASURE button will display the nodularity and increment the measurement count.
All measurement results appear in the results window.
If multiple images are prepared, measurements can be repeated.
8. Graphite%
The graphite area ratio is measured for each image, averaged, and then used as reference data for subsequent Ferrite/Pearlite % evaluation.
9 Report
The results are exported to an Excel file.
10. Ferrite / Pearlite% 측정
Ferrite % and Pearlite % are determined from the etched image,
using the graphite fraction (Graphite %) measured from the unetched image as input.
| Graphite % | The graphite fraction measured from the unetched image |
| Ferrite % | Ferrite면적 / ( Ferrite면적 + Pearlite면적 ) x 100 |
| Pearlite % | Pearlite면적 / ( Ferrite면적 + Pearlite면적 ) x 100 |
The calculation of Ferrite % and Pearlite % is based on the total area, excluding the graphite fraction.
