Behaviour at Nitriding in Fluidized Layer of Austenitic Stainless Steels at the Temperature of 450 °C
Journal Title: Analele Universitatii "Dunarea de Jos" din Galati. Fascicula IX, Metalurgie si Stiinta Materialelor - Year 2007, Vol 30, Issue 1
Abstract
Stainless austenitic steels have a good corrosion resistance but reduced abrasion strength due to low strength below 200HV5. By nitriding one may ensure the obtaining of a superficial layer with increased strength that should maintain unaltered the corrosion resistance. The nitriding in fluidized layer applied at 450 ºC allowed the obtaining of diffusion layers formed of nitrogen enriched austenite with certain nitride separations. For the CrNi, CrNiMo usual steels, the obtained strengths have been higher than 1000 HV005. In the case of steel X1CrNiMoCu20.18.7 with more than 50% of alloying elements, the strengths did not exceed 500 HV005 due to the low nitrogen concentration, much below the saturation limit determined by the reduced diffusion speed. The corrosion test in saline mist indicates the maintaining of corrosion resistance, the materials ranging in the group of Perfectly resistant. Also, the abrasion strength increased 2-3 times due to the limited diffusion speed at low temperature. The favourable property assembly allows the usage of the treatment for some practical applications.
Authors and Affiliations
Ovidiu Dima
Research on the Effect of Temperature and Duration of Immersion on the Layer Thickness of Zinc Coating Obtained in Microalloyed Zinc Melts
This paper aims to establish the influence of temperature and duration of immersion on the thickness of zinc layer deposited through a thermal process, in correlation with the chemical composition of melted zinc. Layers...
Modelling and Numerical Simulation of the Atmospheric Dispersion of Pollutants From an Integrated Iron and Steel Complex - Part II
The Iron and Steel Complex processes handle, store and undertake important amounts of raw materials (iron ores, coals, etc.) energy, fuels, waste waters, slags and other different types of wastes. These activities have a...
The Steam - Secondary Source of Energy in Metallurgy
The paper is focused on a study of how to use the steam from recovery boilers of LD converters to produce electricity in turbine generators and heat in a heat network.
Electrodeposition and Characterization of Ni-Si Nanocomposite Coatings
In this paper is presented morphological aspects and corrosion behaviour of composite coatings having nickel as metal matrix and silicon as dispersed phase obtained during electrodeposition process of nickel. Silicon mea...
Structure and Corrosive Firmness of Composition Materials on the Basis of Copper and Molybdenum Got Method Electron-Beam Technology
The article describe the study of corrosive firmness of composition materials on the basis of copper, obtained by EB-PVD method. Corrosive firmness of condensates was explored by gravimetric method. The especially decrea...