ISO 945-1:2019 pdf free download – Microstructure of cast irons一 Part 1: Graphite classification by visual analysis.
Form and distribution of graphite shall be determined by using the reference images, given in Figures 1 and 2 (see also Annexes A, II and ). 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.
If the microstructure is visualized on a visual display screen, the combined magnification of both microscope and screen (depending on its size) shall be taken into account.
6.2 Evaluation of the analysis results
The evaluation of the analysis results shall be carried out by an operator trained in this metallographic technique.
7 Reference images
7.1 General
A series of reference images (see Figures 1. to ..J showing schematic microstructures and photomicrographs is provided for the classification of the form, distribution and size of the graphite in cast irons.
In addition to reference images, the photomicrographs show actual graphite microstructures (see Annexes A and ).
7.2 Reference images for graphite form
The reference images for the graphite form (see Figure 1) show six characteristic forms which are designated by the Roman numbers I to VI (see also Annex A). These represent the principal types of graphite observed in cast iron materials. Annex C gives the common terminology and the occurrence of these types of graphite.
The graphite forms are specified in the relevant material standards. Percentages of these graphite forms may also be specified by these standards, e.g. in the case of compacted (vermicular) graphite cast irons.
NOTE ASTM A247 defines seven graphite types designated in the reverse order compared to the six forms defined in this document.
7.3 Reference images for the distribution of graphite (form I)
The reference images for the graphite distribution (see Figure 2) show characteristic graphite distributions designated by the letters A to E.
In addition to reference images, the photomicrographs show actual graphite microstructures (see Annex B).
A variant of distribution C, designated C’, is included in Annex B. This distribution corresponds to thin- walled castings.
7.4 Reference images for graphite size
Figures 3, 4 and S shall be used in conjunction with Table 1 to evaluate the graphite size.
For x 100 magnification, sizes are indicated ranging from a maximum size of the particle of> 100 mm (size 1) down to < 1,5 mm (size 8). When using Table 1. alternative magnifications may be used (see Table 1. Notes 1 and 2). NOTE 1 Sizes 1 and 2 have no practical application for graphite forms Ill to VI. Therefore, they have not been included in Figures 4 and 5. NOTE 2 The reference images given in Figure 3,4. and do not represent all the graphite particle sizes present in each of the graphite particle size ranges given in Table 1. NOTE 3 The schematics show some graphite particles smaller than the minimum size graphite particles for each size range. The schematics represent what can be seen when viewing a two dimensional sectioned view of a three dimensional structure where a normal sized particle is sectioned not through its centreline appears smaller than its actual size. 8 Designation of graphite by form, distribution and size 8.1 Designation system To characterize the graphite observed, indications are generally necessary on the form, distribution and size of the graphite particles. For this purpose, the following symbols shall be used at different positions of the designation: — the Roman numbers given in Figure 1 are used for the graphite form at position 1; — for form I, the capital letters given in Figure 2 are used for the distribution at position 2; — the Arabic numbers given in Figures 3,4, and S and Table 1 are used for the graphite size at position 3. EXAMPLE 1 For a grey cast iron with flake (lamellar) shaped graphite particles of form I, distribution A, and size 4, the following designation is used to describe that structure: