Fe–15 wt-Cr–X wt-C hardfacing surface layer: Wear resistance and its enhanced mechanism with C additive

Abstract

An electrode with different C additives was developed. The microstructure of the hardfacing surface layer was observed by optical microscopy. The phase structure was determined by X-ray diffraction. The hardness and wear resistance of the hardfacing surface layer were measured respectively. The worn-out surface and three-dimensional morphology were observed by field emission scanning electron microscope equipped with energy dispersive X-ray spectrometry. The relation curve between mass fraction of M 7 C 3 carbide and temperature was calculated according to thermodynamics software Thermo-Calc. The results show that, with the increase in C additive, the hardfacing surface layer changes from a hypoeutectic structure to a hypereutectic one. Meanwhile, the primary phase changes from austenite to carbide. The hardness and wear resistance of the hardfacing surface layer increase gradually with the increase in C additive, and when the C additive is 25 wt-%, they are the largest. With the increase in C content, the precipitation temperature of M 7 C 3 decreases from 1280 to 1260uC, while the maximum amount of M 7 C 3 increases instead, which is from 0?154 to 0?313. The reason of the improvement for wear resistance of the hardfacing surface layer is that the carbide initiates and the amount of M 7 C 3 increases.

Antifouling Photograftable Zwitterionic Coatings on PDMS Substrates

“…Type II photoinitiators are excited to a short-lived singlet state by absorption of UV light which is quickly transformed to a triplet state. 33 This highly-reactive triplet state initiates the grafting process by abstracting aliphatic hydrogens from the substrate and transferring the radicals to the surface. After this step, polymerization is initiated from the surface and covalently bonds the polymer chain to the substrate (See Fig.…”

Corrosion resistance of niobium-added slag-free self-shielded flux-cored welding overlay in neutral solution

“…Moreover, the partial substitution of C for N improved the resistance to pitting corrosion in Fe-18Cr-9Mn-5.5Ni-0.3(C + N) austenitic stainless steels [19]. Compared to the wear resistance [20][21][22][23], the corrosion resistance of the Fe-Cr-C welding overlay has not studied in detail so far. In this study, the niobiumadded iron-based slag-free self-shielded flux-cored wire was developed and the effect of niobium on neutral corrosion resistance was investigated.…”

Refining effect of nitrogen on M7C3 carbides in hypereutectic Fe–25Cr–4C–0.5Ti–0.5Nb hardface coatings

“…However, as the primary M 7 C 3 carbides are usually coarse, the binding abilities of the M 7 C 3 carbides with the matrix are poor, and they can easily peel off of the matrix. Therefore, the service life of the workpiece manufactured with hypereutectic Fe-Cr-C coatings is short [12][13][14].…”