Enhanced wear and corrosion resistance of plasma electrolytic carburized layer on T8 carbon steel

Abstract

h i g h l i g h t sElectron temperature in plasma electrolytic carburizing process is determined. Diffusion coefficient of carbon in PEC is higher than conventional carburizing. Wear and corrosion resistance of T8 steel are both improved after PEC treatment. Pitting corrosion of steel substrate is obviously suppressed by PEC treatment. t r a c tA hardening layer of 70 mm on T8 carbon steel was fabricated by plasma electrolytic carburizing (PEC) in glycerol solution at 380 V with 3 min treatment. The discharge process was characterized using optical emission spectroscopy (OES), and the electron temperature in plasma envelope was determined. Meanwhile, diffusion coefficient of carbon was calculated on the basis of carbon concentration profile. The tribological property of carburized steel under dry sliding against ZrO 2 ball was measured by a balldisc friction and wear tester. The corrosion behaviors were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). It was found that the carburized layer mainly contained a-Fe and Fe 3 C phases with maximum hardness of 620 HV. The PEC treatment significantly decreased the friction coefficient from 0.4 to 0.1. The wear rate of PEC treated steel was about 5.86 Â 10 À6 mm 3 /N$m, which was less than 1/4 of T8 steel substrate. After PEC treatment, the wear and corrosion resistance of T8 steel were improved. Particularly, the pitting corrosion of steel substrate was obviously suppressed.

Effect of Sub-Zero Treatments and Tempering on Corrosion Behaviour of Vanadis 6 Tool Steel

“…In addition, an opposite effect can occur, where increased carbides/matrix surface area ratio may contribute to the retardation of corrosion since a more stable protective film on the surface of these carbides can be formed. Experimental investigations of the effect of cementite on the corrosion resistance of carbon steel provided a good example of a much nobler response of cementite on corrosion attacks and confirmed improved corrosion behaviour of the material when coated with Fe 3 C [49].…”

Cryogenic Treatment of Martensitic Steels: Microstructural Fundamentals and Implications for Mechanical Properties and Wear and Corrosion Performance

“…For ledeburitic steel tools operating in harsh corrosive environments, corrosion resistance is a key parameter that determines their durability. Carbides are known to exhibit much more noble behaviour in a variety of corrosive environments and can effectively protect metallic surfaces from corrosion [348]. Cryogenically treated ledeburitic steels contain more carbides; therefore, a larger area fraction of their exposed surfaces is covered with phases that are comparatively more noble than ferrite or austenite.…”

Corrosion Resistance of Vanadis 6 Steel after Conventional Heat Treatment and Sub-Zero Treatment in Cold Nitrogen Gas Followed by Tempering

“…Better resistance of the matrix of SZT specimens may be associated with significantly enhanced number and population density of SGCs. It is known that carbides have much more noble behaviour in a variety of corrosion environments, and can protect metallic surfaces against the corrosion effectively [16]. In the SEM micrograph of corrosion pit developed on specimen that was subjected to the SZT, Fig.…”