TITLE:
Sintering and Wear Behavior of a FeCrCB Hardfacing Alloy Applied by Tape Casting: A Study of Cooling Rate Effect
AUTHORS:
Fernando Valenzuela de la Rosa, Roal Torres Sánchez, José T. Holguín-Momaca, Carlos Domínguez Ríos, Alfredo Aguilar Elguezabal
KEYWORDS:
Hardfacing, Sintering, Cooling Rate, Wear Resistance
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.8 No.5,
September
10,
2020
ABSTRACT: This study presents a simple process to deposit a hardfacing coating on a
steel substrate, based on the sintering of metallic powder applied by tape
casting (by a slurry of metallic powder suspension onto a steel substrate) thus
avoiding the use of traditional welding processes and their variants. The
effect of the cooling of hardfacing after the sintering process, by air at room
temperature or by quenching in water, was studied. This new method ensures a
good metallurgical bonding between the substrate steel and the hardfacing layer
and shows mechanical property improvement on coated pieces, similar to those
exhibited by hardfacing coatings produced by several kinds of welding
processes. The characterization of the hardfacing coatings was made by X-ray diffraction,
optical microscopy, scanning electron microscopy, microhardness and wear
resistance according to the ASTM G65 standard. The characterization results show that the presented faces are: M7C3,
M3C, MC, M2B and M23B6; there are
three different phases in the micrograph glass phase, eutectic phase and hard
phase with a volumetric fraction of 0.14, 0.20 and 0.66, respectively, for the
air cooled and 0.15, 0.16 and 0.69 when quenched in water. The average
microhardness value for the parts cooled in air was 832.5 HV and for that
cooled in water was 958.9 HV, and the wear resistance was a mass loss of 0.219
and 0.128 g for parts cooled in air and water, respectively. These results show
that the hardfacing coating could have twice the hardness and wear resistance
than that observed for the boron steel used as a substrate.