Non-metallic inclusions (sulphides, oxides, silicates) affect the fatigue strength, toughness and machinability of steel. A section polished parallel to the rolling direction is examined unetched under the microscope, and inclusions are rated by type and size against standard charts.
The test is performed with a method accredited by TÜRKAK under TS EN ISO/IEC 17025 (ISO 4967); results are issued as an accredited test report.
Determined Values
- Type A (sulphide), B (alumina), C (silicate) and D (globular oxide) inclusions
- Thin and heavy series ratings
- Type DS single large inclusions
Applied Standard
- ISO 4967 – Steel, determination of content of non-metallic inclusions, micrographic method using standard diagrams
Specimens and Reporting
The specimen is cut, mounted, ground, polished and, where needed, etched with a suitable reagent in our laboratory (ASTM E3). Examination is done with a metallurgical microscope and image analysis software; results are reported with scaled micrographs.