Wear of grinding rotors with thermally-sprayed coatings in a high-speed mill
Loading...
Date
2018-10-15
ORCID
Advisor
Referee
Mark
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Altmetrics
Abstract
In this paper, the erosion behavior of three types of protective thermally-sprayed coatings and non-coated
substrate steel was investigated under semi-industrial test conditions using a laboratory high-speed pin mill
DESI-11. The grinding in the mill was performed by two counter rotors, on which protective coatings were
deposited either by atmospheric plasma spraying (APS) (Cr3C2-NiCr and NiCrBSi coatings) or by high velocity
oxy-fuel (HVOF) process (WC-CoCr coating). The grinding rotors with deposited coatings were used for milling
of the Portland cement, and rotors' weight loss was monitored after milling of 1, 3, 5, 10, and 15 kg of this
material. The lowest weight loss in the mixed impact erosion conditions was exhibited by WC-CoCr coating,
which was followed by Cr3C2-NiCr and NiCrBSi coatings. The greatest material removal on the anterior and the
right lateral faces of rotor pins was a result of erosion damage at high impact angles through surface fatigue wear
and the following failure of protective coatings down to the substrate. In contrast, the top and the left lateral
faces of the pins were subjected mostly to the ploughing and microcutting at oblique impact angles that resulted
in significant erosive damage only if hardness of the pin was lower than that of the Portland cement (Cr3C2-NiCrcoated
and non-coated steel pins). The study also found a significant disproportion between the volumetric wear
losses of various rows of pins of grinding rotors. The central part of the grinding tool consisting of two counter
rotors (both rows of 2-row rotor and a middle row of 3-row rotor) suffered more intensive erosion wear than the
external part (outer rows of 3-row rotor). The design of the mill and the resulting variability in parameters of
milled powder particles at different sites of the grinding tool (such as particle size, particle flux and particle
velocity) were considered as main reasons of this phenomena.
Description
Citation
Document type
Peer-reviewed
Document version
Accepted version
Date of access to the full text
Language of document
en
Study field
Comittee
Date of acceptance
Defence
Result of defence
Document licence
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
http://creativecommons.org/licenses/by-nc-nd/4.0/