5.6.3.2 Corrosion
in the Melt
5.6.3.2.1 Test conditions
Corrosion tests must always be properly
related to the real conditions of the application. The relevant
stress criteria, and the way in which the material can be
expected to behave as it interacts with the corroding medium,
must be estimated beforehand.
Points that need consideration include:
- thermal stresses,
- chemical aspects,
- the type of material to be examined and
- mechanical stress.
5.6.3.2.2 Bestimmung der Korrosionshöhe
Test procedures for corrosion in the melt
are, in contrast to liquid phase corrosion, covered by national
and international standards. The most important of these standards
are:
- measurements of the wetting angle using an HT reflected
light microscope,
- the crucible slagging process (DIN 51069-2),
- the scattering and tapping process (ASTM C 768) and
- the dip process (finger test) (ASTM C 874).
In summary: The corrosion of refractory materials in liquid
slags and metallic melts is a complex process whose details
are difficult to understand. Standardised test procedures
are therefore only relevant if they reflect the conditions
that will apply in practice.
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