Results are provided for a study of an aluminized coating corrosion resistance on the surface of alloys of the Fe–Cr–Al system (fechrals) and austenitic corrosion-resistant steel 12Kh18N10T under ...conditions of a temperate climate humid atmosphere containing chlorides. Coatings are applied by immersion in a melt. A study of corrosion during variable immersion of specimens in a 3% aqueous solution of sodium chloride show that coatings of the Fe–Cr–Al system prepared by aluminizing withstand long-term exposure to the environment (corrosion rate is 0.0003 g/(m
2
·day). An aluminized coating on a steel 12Kh18N10T surface has twice as good corrosion resistance indicators than for a coating on a Kh15Yu5 substrate.
The effect of laser treatment parameters for copper cladding applied by explosive welding and subsequent rolling on a titanium surface on coating structure and phase composition is studied. It is ...shown that the relative (compared with VT1-0 titanium alloy) wear resistance of a coating with an increase in titanium content from 30 to 50% increases at 20°C from 2.9 to 4.4, and at 400°C from 1.7 up to 2.0.
This work studies the oxide film structure on the surface of cylindrical ingots made of 6000 series aluminum alloy after homogenization annealing and tests with alternating immersion in an ...electrolyte based on sodium chloride using electron microscopy and energy dispersive analysis. Results reveal a 40–200% increase in weight loss in areas covered with white bloom when the active environment impacts the ingot surface due to the presence of defects in the oxide film structure. In addition, the corrosion rate increases by a factor of 2–3 compared to the clean zones, while passivation processes are not noted on both parts of the surface. Defects in the structure of the oxide film are associated with the partial reduction of aluminum oxide during diffusion annealing at the site of contact with organic contaminants.
The article reports findings on theoretically-calculated data and experimental results obtained with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy methods of the ...analysis of hard alloys produced by the explosive compaction of the Cr3C2 chromium carbide powders with titanium, first in the original condition and then after heating to 1200 °C. It was established that when heated to 600 °С the phase composition of hard alloys does not change and corresponds to the composition of the original components of the powder mixture. When the heating temperature was increased to 650 °С, new fine powder fractions emerged at the “chromium carbide – titanium” interface. At the temperature of 700 °С two separate diffusion layers emerged and grew in the opposite directions. Due to this growth the source phases in the alloy fully disappeared at 1200 °С and two equilibrium phases were formed.
The paper discusses the formation of hydrophobic coatings based on linseed oil and copolymers of glycidyl methacrylate and (fluoro)alkyl methacrylates on the surface of pinewood and shows the ...possibility of achieving a superhydrophobic state with contact angles as large as 154°. Energy-dispersive X-ray analysis has been employed to show that methacrylate copolymers are uniformly distributed over the wood surface and penetrate to a depth of more than 400 µm. The proposed modification of wood imparts it with stable water-repellent properties, which slow down moisture sorption at the initial stages of a contact with water and reduce water absorption coefficient by a factor of 2.5 after 60-day exposure in water.
Results are provided for a study showing the effect of Ca- and Ba-containing master alloys on composition and contamination with non-metallic inclusions during extra-furnace treatment and casting ...(ladlefurnace → evacuation → continuous casting) of steel 26KhMFBa. It is shown that the use of SK30
wire
master alloy after evacuation, leads to incomplete modification of refractory aluminate inclusions. Use of SKBa15R
wire
master alloy before evacuation leads to maximum reduction in overall contamination with readily melting inclusions. Successive treatment with SKBa15R
wire
and SK30
wire
after evacuation leads to maximum reduction in refractory aluminate inclusions. Presence of low-melting inclusions is preferable since this type of inclusion is not deposited on the walls of a pouring nozzle and does not adversely affect contamination of continuous casting machines and products obtained from them. Evaluation of the quality of continuously-cast billet metal shows that use of a Ba-containing master alloy makes it possible to prepare a continuously-cast billet with maximum contamination by inclusions not exceeding 1.0 points.
Electron microscopy and energy dispersion analysis are used to reveal structural features of an oxide film in the region of white deposit areas that are visually detected on the surface of ...cylindrical ingots of 6000 series aluminum alloy after homogenizing annealing. It is shown that a loose film of aluminum and magnesium oxides with an anomalously high Mg content (up to 45 at.%) and micropores are typical for these areas. Diffusion flow of magnesium towards the surface during homogenizing annealing gives rise to its chemical potential gradient occurring as a result of oxidation processes occurring during annealing. Reasons are determined for the occurrence of white deposit areas connected with formation at an ingot surface of mineral salt oxides and organic compounds from dried liquid used for cooling during ingot semi-continuous casting.
Establishing basic friction parameters of new hard alloys to be used for the fabrication of sliding weight-bearing components that work in conjunction with silicified graphite in water lubrication is ...an important task. Completing this task will help determine principles for selecting a tailored arrangement of components to comply with the operational conditions of the friction pair. The antifriction properties and durability of chromium carbide hard alloys during sliding friction over silicified graphite in water are conditions generated by alloy hardness and chromium carbide volume fraction in the material structure. The wear of a friction pair may be reduced by one order of magnitude if explosively pressed chromium carbide and titanium-based alloys replace such traditional materials as silicified graphite or hard alloys of chromium carbide with nickel.
The paper presents the results of research into how the binder content and the Shockwave compression parameters affect SiC and Ti powder mixture densification in explosive compaction. The ...microstructure of the resulting compacted metal was studied by scanning electron microscopy. Phase and chemical composition was studied by X-ray crystallography and energy-dispersive analysis. It was found that at higher silicon carbide concentrations and higher powder heating temperatures, Shockwave compression reduced the residual porosity of the compacted metal to 2%. The microstructure was a carbide-silicon matrix with titanium inclusions. The obtained material matched the initial components in phase composition.
Results of a study of the effect of the conditions of heat treatment on the structure and properties of explosion-welded steel–aluminum composite with different diffusion barriers are reported. The ...creation of diffusion barrier from either nitrated steel layer or chromium sublayer between aluminum and steel was shown to increase the temperature stability of steel–aluminum composite at the expense of deceleration of diffusion processes and shift of the temperature range of the onset of the formation of intermetallics to the high-temperature range.
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