The combined effect of superficial nanocrystallisation by SMAT (Surface Mechanical Attrition Treatment) followed by plasma nitriding on the mechanical properties of a medical grade austenitic stainless steel was studied. SMAT conditions were optimised to enhance nitrogen diffusion. Experimental observations (energy dispersive X-ray spectroscopy profiles, cross-sectional optical micrographs, pha...

The effect of the initial microstructure (recrystallized or cold-rolled) on the nitride-precipitation process upon gaseous nitriding of ternary, ferritic, Fe-Cr-Al alloy was investigated at 450°C. In the recrystallized specimens, precipitation of metastable ternary, cubic, NaCl-type mixed Cr1xAlxN took place, whereas in the cold-rolled specimens precipitation of firstly binary cubic NaCltype Cr...

Abstract The results of experiments on low-energy implantation AISI 321 stainless steel by nitrogen ions are presented. treatment was carried out a pulsed beam obtained using ballistic ion focusing system. surface modification occurs with the formation two-layer structure, which is typical for ion-plasma nitriding processes steels. thickness modified layer can reach 27 μm after 1 hour treatment...

Abstract A typical nitrogen expanded austenite layer is formed by plasma-based low-energy ion implantation (PBLEII) on AISI 304L austenitic stainless steel at a moderate temperature of 380 °C. The dislocation self-organization structure in the characterized as an evolution from partial and Lomer-Cottrell dislocations inner near interface to multilayer stacking faults outer nitrided layer. self-...

Corrosion is one of the major problems in the industry especially on machinery since it weakens the structure of the machinery part and causes the mechanical failure. This will stop the production and increase the maintenance cost. In this study, the corrosion behaviour of gas nitriding on a screw press machine shaft made from AISI 4140 steel was investigated. Pitting corrosion was identified a...

- The mechanism of diffusion layer growth in plasma nitrided coatings applied on a St52 steel using an active screen is investigated. The nitriding was performed at 450,500 and 550 ◦C temperature nitriding times of 5, 10 and 15 h, in a gas mixture containing 20 vol. % H2: 80 vol. % N2 and DC-pulsed plasma nitriding unit. The surface, cross section and the thickness of diffusion of specimens ...

The paper investigates the influence of ion-nitriding process on microstructure, corrosion resistance, and tensile strength at elevated temperatures Haynes 282 nickel superalloy specimens produced by Direct Metal Laser Sintering (DMLS) technique. study was performed for two conditions, i.e., as-built DMLS method + covered a layer containing CrN Cr2N phases. An analysis surface morphology reveal...

The ion nitriding behavior of AISI 316L austenite stainless steel was investigated at different times (2 h, 4 and 9 h) temperatures (450 °C, 500 550 °C). structural characterization has been assessed by several considerations which can be listed: (i) the evaluation phase distribution through Rietveld analysis X-ray diffraction patterns accompanying peak fitting process, (ii) hardness profile re...