Material defects and anomalies in the steel
and at finished components
German 
English
Material defects are unwanted concomitants at the melting of steel, the
steel forming or the heat treating. Furthermore faults can occur by improper storage
or subsequent processing. Material defects can appear in different forms.
As an example the following defects have to be mentioned
here :
non metallic inclusions
to high surface decarburization
bad microstructure
surface corrosion
mechanical damage
surface defect
Examinations and micrographs to material defects and
microstructure anomalies as well as their cause are represented under the following
references. The represented pictures of defects are also partly found in the same form
at other materials.
The represented examples don't have to lead to the
failure of the material in every case. These are merely examinations of indications
on the material surface and material insides as well as of structure anomalies, which
differs from the standard.
At the enlarged views a measuring function is available.
The measuring spots 1 and 2 get specified with the left mouse button and the distance
between them gets computed on base of the magnification scale. An optical measuring
point marking takes place on the screen by means of little measuring crosses. For the
use of the measuring function you must activate Javascript in your browser.
Measuring accuracy of the different magnifications:
12,5 : 1 ca. 9 µm
50 : 1 ca. 2 µm
100 : 1 ca. 1 µm
200 : 1 ca. 0,5 µm
500 : 1 ca. 0,2 µm
1000 : 1 ca. 0,1 µm
The examinations are partitioned in 3 categories.
Surface defect
Topics : cracks , grooves , damages , slags , scabs
and corrosion
Internal defects
Topics : blow holes , slags , segregations and degree
of purity
Microstructure
anomalies
Topics : surface decarburization , crystalline structure
and segregations