ISO 945-1:2019

ISO 945-1:2019 pdf free.Microstructure of cast irons -Graphite classification by visual analysis.
4.5 Visual classification of graphite
The reference images given in Figures 1, 2 3., 4 and 5. provide a basis for classifying graphite forms, distribution and size. The characteristic features of the graphite which occur are designated by letters and numbers. For this purpose, microstructures of graphite are arranged in a series of reference images consisting of schematic microstructures of cast irons. The form, distribution and size of the graphite observed are determined by comparison with the reference images. The classification is allocated as the same as that of the images that resemble them most closely at the same magnification.
NOTE The comparison of actual microstructures with schematic images or photomicrographs depends on the subjective impression of the metallographer.
5 Sampling and sample preparation
5.1 Samples taken from a casting
When taking samples from a casting, it is essential that attention be paid to the location, to the wall thickness, to the distance from the surface and to the presence of chills. The location of the sample in the casting shall be recorded in a report.
If more than one casting is examined, the samples shall be taken from the same location in each casting for the purpose of comparability.
The location of the metallographic specimen shall be agreed between the manufacturer and the purchaser.
5.2 Sample preparation
The area of the polished surface to be examined shall be sufficient to give a true representation of the graphite structure. Attention shall be paid to the careful grinding and polishing of the samples, so that the graphite particles appear in their original form, size and distribution. Inappropriate grinding and polishing can cause an unacceptable alteration of the microstructure. If necessary, the method of polishing may be agreed between the manufacturer and the purchaser.
The examination of the graphite under the microscope is usually carried out on the unetched polished section.
6 Procedure for graphite classification
6.1 Procedure for visual classification of graphite
The polished samples shall be scanned under a microscope in such a manner that a representative area is examined. To examine the graphite form and distribution, a x 100 magnification should preferably be chosen. If necessary, the magnification may be adapted in relation with the wall thickness so that the form and distribution of graphite can be determined by using the reference images given in Figures 1 and 2 (see also Annexes A. and j. Adjust the microscope magnification to match as closely as possible the corresponding images in Figures 1 and 2 before classifying the graphite form and its distribution, if appropriate. The graphite size is determined by reference to Figures 3. 4 and S and Table 1, preferably at x 100 magnification. Other magnifications are permitted (see Table 1, Notes 1 and 2, as well as 2.4).
Examination under the microscope is carried out by direct observation in the microscope or by projection on the ground glass of the microscope or on a visual display screen. The area of view should preferably have approximately the same size as the reference images (about 120 mm diameter). The measurement of the graphite particles can be facilitated by the use of suitably calibrated eye-pieces.ISO 945-1 pdf download.

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