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The study investigates the effect of RF plasma on the commercial SS201 and Steel alloys physical, structural and nuclear properties, using an atmosphere of nitrogen (85%) plus acetylene (15%) at 500 W working for 0.5 h. The results were compared with untreated alloys and AISI304L. The study indicated the ability of RF plasma to improve both the mechanical and tribological properties of treated alloys compared to the original commercial alloys and the AISI304L, and achieve good shielding properties for industrial/nuclear applications. [Display omitted] • Commercial SS201 and steel alloys are common/essential materials for the construction of many industrial/nuclear applications. • The impact of RF plasma carbonitriding on the commercial alloys compared with the standard AISI304L has been investigated. • The carbonitriding surface engineering process upgrades both mechanical/tribological properties ofCommercial alloys. • The RF plasma process achieves equivalent radiation shielding properties for the carbonitrided commercial alloys. [ABSTRACT FROM AUTHOR]

Abstract: Surface of 304 AISI austenitic stainless steel has been modified using duplex treatment technique of nitriding and carbonitriding. A thick modified nitrided layer, of approximately 20 µm, has been achieved when rf inductively coupled plasma was adjusted at 450 W for processing time of only 10 min. After performing the nitrided layer, the nitrided samples were carbonitrided using the same technique at different acetylene partial pressure ratios ranges from 10% to 70%, the balance was pure nitrogen. Different amount of nitrogen and carbon species are diffused underneath the surface through the nitrided layer during carbonitriding process and are found to be gas composition dependent. The treated samples were characterized by glow discharge optical spectroscopy, X-ray diffractometry, scanning electron microscopy and Vickers microhardness tester. The microstructure of the duplex treated layer indicates the formation of γ́-Fe4N, Fe3C, CrN and nitrogen-expanded austenite (γN). The thickness of the duplex treated layer increases with increasing the acetylene partial pressure ratio. The surface microhardness of duplex treated samples has been found to be gas composition dependent and increased by 1.29 fold in comparison to the nitrided sample. [Copyright &y& Elsevier]

Abstract: The present work reports on the effect of input plasma processing power in the range of 350–650W on the microstructure and mechanical properties of plasma nitrided Ti. The plasma processing time was 20min and a gas mixture of 15% C2H2 and 85% N2 was used. The characteristics of the carbonitrided layer have been investigated by microhardness measurements, surface roughness measurements, optical microscopy, and X-ray diffraction. The measured surface hardness values of the compound layer shows a maximum of 2050HV0.1 for the sample treated at a plasma power of 550W. The thickness of the carbonitrided layer continuously increases as the plasma power increases. Moreover, the highest carbonitriding rate of 3.52μm2/s was observed when the input plasma power was adjusted at 600W. This high carbonitriding rate of treated titanium samples is ascribed to the high concentration of active carbon and nitrogen species in the plasma atmosphere and the formed microcracks in the near surface of the sample during the plasma processing. [Copyright &y& Elsevier]

Inductively coupled radio frequency plasma surface treatment was applied to commercially pure titanium sheets. The goal was to increase the efficiency of the carbonitriding process, i.e., to decrease the plasma treatment time to a few tens of minutes instead of several hours. The effects of different plasma-processing times on the microstructure and mechanical properties of plasma-carbonitrided Ti were examined. The characteristics of the carbonitrided layer were investigated by microhardness testing, surface roughness measurements, optical microscopy and X-ray diffraction. The surface microhardness and the thickness of the compound layer of carbonitrided Ti increase with the plasma-processing time. Surface energy, yield strength and Young’s modulus for carbonitrided titanium were calculated from the Vickers microhardness data. An attempt was made to interpret the high carbonitriding rate and the high microhardness values of carbonitrided titanium with respect to previously published results. [ABSTRACT FROM AUTHOR]