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This paper presents new technology for stainless steel wire processing. This technology consists of using cryogenic cooling immediately after the wire leaves the drawing die. Results of a laboratory experiment show that use of cryogenic processing after wire drawing improves mechanical properties compared with traditional drawing. Metallographic analysis proves that deformation conditions during cryogenic drawing are an additional factor for realization of structural resources to optimize steel wire physical and mechanical properties. [ABSTRACT FROM AUTHOR]

In this paper the influence introducing various plasticizers into an initial charge on the structure and properties of iron-based powder materials alloyed with copper is considered. It is shown that introduction of copper stearate into an initial powder mixture and warm mixing, pressing and subsequent sintering makes it possible to obtain low-porosity workpieces with relative porosity of 95%. Pores within the workpieces obtained have a small size of 10–15 microns and a rounded shape. Also, bending strength is determined for sintered samples of all the compositions of powder mixtures studied and the Rockwell hardness is determined on the C scale. Powder steels based upon mixtures have the best set of mechanical properties PZhRV 2.200.28 + 0.7 wt.% Br + 0.7 wt.% Cu + 1 wt. % StCu + warm mixing—hardness HRC 58. flexural strength 600 MPa PZhRV 2.200.28 + 1.4 wt.% Br + 1.4 wt.% Cu + 1.4 wt.% C + 1.0 wt.% StFe + warm mixing—hardness HRC 100, flexural strength 530 MPa [ABSTRACT FROM AUTHOR]

This paper is dedicated to studying the effect of replacing molybdenum with vanadium on the tendency to amorphisation, structure, and thermal properties of high-entropy alloys of the (Fe0.25Ni0.25Co0.25Cr0.125Mo0.125‑xVx)100‑yBy system, where x = 0; 0.0625; 0.125 and y = 17–25. The alloy structure was analyzed using X‑ray diffraction, scanning and transmission electron microscopy methods. Thermal properties were determined by differential scanning calorimetry. It was found that the replacement of molybdenum with vanadium leads to the formation of crystalline particles of complex nitrides (V, Cr, Mo)(N, B) in the ribbon structure. The dependences of the characteristic alloy temperatures have been established. Molybdenum replacement with vanadium was shown to stabilize the supercooled liquid in alloys with completely amorphous structure. [ABSTRACT FROM AUTHOR]

The paper presents the results of cobalt corrosion tests in air at different temperature and humidity values. It was demonstrated that corrosion losses in cobalt at temperatures of 20 and 30 °C and relative humidity of 70, 80, and 95% are insignificant. However, the rate of cobalt corrosion sharply increases at an air temperature of 50 °C, especially at 95% relative humidity. A conclusion about the intensity of the cobalt corrosion processes under these conditions can also be derived from the sample appearance: after testing at 50 °C and 70% humidity, the samples turn black, while at 50 °C and 95% humidity they become covered with black, oily, and easily crumbling flakes, which represent the products of cobalt corrosion. It was found that corrosion film formed on the cobalt surface consists of the eutectic Co–CoO mixture of variable composition and CoO·Co(OH)2·H2O complex oxide. At increased corrosion test temperatures, the surface film of hydrated cobalt oxide becomes thicker, develops microcracks, and leads to the formation of cobalt hydroxide flakes, which exhibit weak adhesion to the substrate and crumble. [ABSTRACT FROM AUTHOR]