ISO 945-4:2019 pdf free.Microstructure of cast irons -Test method for evaluating nodularity
in spheroidal graphite cast irons.
4 Designations
4.1 Graphite classification by visual analysis
To characterize the graphite particles observed, information is generally necessary on the nodularity, the size and the number of the graphite particles. For this purpose, the following symbols shall be used at different positions of the designation.
a) Nodularity is designated by a percentage, in increments of five percentage points; see the reference images of Figure Ad.
NOTE 1 Nodularity of spheroidal graphite cast irons Is 50 % as a minimum. Maximum nodularity is usually about 95 %.
b) Graphite particle size is designated by numbers from 3 to 8 in accordance with ISO 945-1. For determining the size range, the largest graphite particle in the field of view is used in accordance with ISO 945-1. lithe graphite particles observed in different areas of view cover two sizes, reference to both is possible in accordance with ISO 945-1.
NOTE 2 The reference images given In ISO 945-1 do not represent all the graphite particle sizes that can be present in each of the graphite particle size ranges. The reference image schematics In ISO 945-1 show some graphite particles smaller than the minimum size graphite particles for that size range. The schematics represent what can he 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.
c) Graphite particle count is designated by numbers; see the reference images of Figure Bi..
EXAMPLE 1 For a spheroidal graphite cast iron, the nodularity, graphite particle size and graphite particle count are 90 %, size 7 and 200 particles/mm2, respectively. The structure is described as follows:Nodularity 90 %; size 7; 200 particles/mm2.
EXAMPLE2 For a spheroidal graphite cast iron, the nodularity and graphite particle count are evaluated to be 90 % and 200 particles/mm2 and the graphite sizes cover size 6 and size 7. The structure is described as follows:
Nodularity 90 %; size 6/7; 200 particles/mm2.
The predominant size may be emphasized by underlining the number.
4.2 Graphite classification by image analysis
When a cast iron material is examined using the image analysis method in accordance with
ISO/TR 945-2, the graphite particles should be classified by the following elements.
a) Nodularity, designated by a percentage number calculated according to Formulae (1) and (2). The
results should be reported in whole numbers. For example, 92,6 % is reported as 93 %.
b} Size, designated by numbers from 3 to 8 in accordance with ISO 945-1. For determining the size
range, the largest graphite particle in the field of view is used in accordance with ISO 945-1. If the
graphite particles observed in different fields of view cover two sizes or more, reference to these
size ranges is possible.
c) Graphite particle count, designated by numbers.
EXAMPLE 1 For a spheroidal graphite cast iron, the calculated nodularity, graphite size and graphite
particle count are 92,4 %, size 6 and 230 particles/mm2, respectively. The following designation should be used to describe this structure:
If the graphite particles evaluated in different fields of view cover more than one size, the size and
the particle number should be presented in percentage.
EXAMPLE2 For a spheroidal graphite cast iron, the calculated nodularity and graphite particle count are 92,6 % and 230 particles/mm2. 52 % of the graphite particles are in the range of size 6, 45 % in the range of size 7 and 3 % in the range of size 5. The following designation should be used to describe this structure: Nodularity 93 %; 52 % size 6 + 45 % size 7 + 3 % size 5; 230 particles/mm2.ISO 945-4 pdf download.