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INVESTIGATION ON THE TRIBOLOGICAL

BEHAVIOR OF ARC-SPRAYED AND HAMMER-

PEENED COATINGS USING TUNGSTEN

CARBIDE CORED WIRES

W. Tillmann, L. Hagen, and P. Schröder

Due to their outstanding properties, WC-W

C iron-based

cermet coatings are widely used in the field of wear protec-

tion. Regarding commonly used WC-W

C reinforced coating

systems, it has been reported that their tribological behavior is

mainly determined by the carbide grain size fraction. Although

the manufacturing route for arc-sprayed WC-W

C cermet coat-

ings is in an advanced state, there is still a lack of knowledge

concerning the performance of cored wires with tungsten car-

bides as filling material and their related coating properties

when post-treatment processes are used, such as machine

hammer peening (MHP). A major objective was to character-

ize WC-W

C FeCMnSi coatings deposited with different carbide

grain size fractions as a filling using cored wires, with respect

to their tribological behavior. Moreover, deposits derived from

cored wires with a different amount of hard phases are inves-

tigated. According to this study, polished MHP surfaces are

compared to as-sprayed and polished samples by means of

metallographic investigations. With the use of ball-on-disk and

dry rubber wheel tests, dry sliding and rolling wear effects on

a microscopic level are scrutinized. It has been shown that the

MHP process leads to a densification of the microstructure for-

mation. For dry sliding experiments, the MHP coatings obtain

lower wear resistances, but lower coefficients of friction than

the conventional coatings. With regard to abrasion tests, the

MHP coatings possess improved wear resistance. Strain hard-

ening effects at the subsurface area were revealed by the me-

chanical response using nanoindentation. However, the MHP

process caused a cracking of embedded carbides, which favor

breakouts, leading to advanced third-body wear (Fig. 3).

ANTI-ICING BEHAVIOR OF THERMALLY

SPRAYED POLYMER COATINGS

Heli Koivuluoto, Christian Stenroos, Mikko Kylmälahti,

Marian Apostol, Jarkko Kiilakoski, and Petri Vuoristo

Surface engineering shows increasing potential to pro-

vide a sustainable approach to icing problems. Icing reduces

safety, operational tempo, and productivity, as well as the

reliability of logistics, industry, and infrastructure. Currently,

several passive anti-icing properties adaptable to coatings are

known, but further research is required to proceed into practi-

cal applications. An icingwind tunnel and centrifugal ice adhe-

sion testing equipment can be used to evaluate and develop

anti-icing and icephobic coatings for potential use in various

arctic environments, e.g., in wind power generation, oil drill-

ing, mining, and logistic industries. The present study deals

with evaluation of icing properties of flame-sprayed polyeth-

ylene (PE)-based polymer coatings. In laboratory-scale icing

tests, thermally sprayed polymer coatings showed low ice ad-

hesion compared with metals such as aluminum and stainless

steel. The ice adhesion strength of the flame-sprayed PE coat-

ing was found to have approximately seven times lower ice

adhesion values comparedwithmetallic aluminum, indicating

promising anti-icing behavior (Fig. 4).

CAN THERMALLY SPRAYED ALUMINUM (TSA)

MITIGATE CORROSION OF CARBON STEEL IN

CARBON CAPTURE AND STORAGE (CCS)

ENVIRONMENTS?

S. Paul and B. Syrek-Gerstenkorn

Transport of CO

for carbon capture and storage (CCS)

uses low-cost carbon steel pipelines due to their negligible

corrosion rates in dry CO

. However, in the presence of liquid

water, CO

forms corrosive carbonic acid. In order to mitigate

wet CO

corrosion, use of expensive corrosion-resistant alloys

is recommended; however, the increased cost makes such a

selection economically unfeasible. Therefore, new corrosion

mitigation methods are sought. One such method is the use

of thermally sprayed aluminum (TSA), which has been used to

Fig. 3 —

Cross-sectional images taken by light microscopy showing

the coating morphology across the non-MHP and MHP area at

sample (2,0).

Fig. 4 —

3D optical profiles of impact craters of flame-sprayed PE

coatings after high-velocity impact test at room temperature (RT).

JTST

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