Sliding wear of various materials in molten zinc

Abstract

A full journal bearing tester was built to study wear behaviour of materials sliding in molten zinc. Various material combinations, including cobalt based superalloys, cermet coatings (on 316L stainless steel substrates), and ceramics were evaluated at conditions similar to continuous galvanising line (CGL) operations. Metallographic and chemical analyses were conducted on tested specimens to characterise the wear. Cobalt based superalloys not only suffered considerable wear but also reacted with molten zinc to form intermetallic compounds. Cermet coatings and ceramics experienced noticeable wear although they were non-wettable and did not react with zinc baths. The study showed that MgO stabilised ZrO 2 suffered the most wear when running against laser clad WC coated 316L while the combination of SiAlON and laser clad WC coated 316L showed the least amount of wear. The composite nature of hard particles imbedded in a soft matrix, posing resistance against both abrasive and surface fatigue wear, is believed to be the reason that laser clad WC coatings can withstand wear in molten zinc.MST/5231

Electron-Beam-Induced Topographical, Chemical, and Structural Patterning of Amorphous Titanium Oxide Films

“…Blue zones were attributed to a strong presence of crystalline or amorphous Ti 2 O 3 .The ex-situ taken optical images of the irradiated spots in Figure b and c prior to plasma cleaning demonstrate a color change limited to the irradiated area, whereas after the most intense irradiation in Figure a, the blue appearance is visible around the irradiated spot ( D = 2.0 μm) because of the heat dissipation from the intensely heated beam center (Table ) to the surrounding oxide. It is well-known that heating in UHV usually creates small quantities of Ti 3+ defects . The ring visible in Figure b and c within the blue zone is due to hydrocarbon deposition during WDX analysis with a relatively low beam current of 40 nA.…”

“…Local modifications in crystalline TiO 2 films or powders have been obtained by ion implantation and laser and electron beam (e-beam) irradiation, while local functionalization in amorphous TiO 2 have not been reported today. Even so, a-TiO 2 can be obtained by plasma-enhanced chemical vapor depositon , or by magnetron sputtering; crystalline films are mostly aimed at because of slightly better dielectric constants 18 and probably also because TiO 2 in the crystalline state is better investigated than in the amorphous state. After laser irradiation at 335 nm of rutile pellets, Le Mercier and co-workers , found a drop in electrical resistance from 10 9 to 10 Ωcm.…”

Fracture toughness and sliding properties of magnetron sputtered CrBC and CrBCN coatings

“…To date, the tribological properties of various coatings including sulfides [12,13], carbides [14], nitrides [15,16] and borides [17][18][19][20] were investigated based on their potential application for bearings.…”

Corrosion behaviour of stoichiometric Fe3Si alloy in liquid zinc

“…In the continuous hot dip galvanising process, corrosion of the immersed equipment components such as sink rollers and immersion heaters is an inevitable problem, as the processing equipments used in continuous hot dip galvanising parts were exposed to liquid zinc, which may cause severe quality and productivity problems for the plated steel. [1][2][3] Galvanisers must periodically stop the continuous galvanising lines to replace hardware components. Therefore, much research has been carried out to extend the life of these components to improve the cost effectiveness of the galvanising industry.…”