EFFECTS OF NITROGEN PRESSURES ON THE NATURE OR THE COMPOUND LAYER FORMED DURING ION-NITRIDING OF ARMCO IRON

Abstract

The effects of partial pressure of nitrogen on the nature of the compound layer formed during ion nitriding of Armco iron in the temperature range of 475° - 550°C was investigated using nitrogen hydrogen gas mixtures. The effects were followed by X-Ray diffraction techniques and optical metallography. It has been observed that at low nitrogen pressures the compound layer formed is monophase y'-nitride while at higher partial pressures of nitrogen the compound layer is a mixture of y', and 6-nitrides. The thickness of the compound layer has also been found to increase with increasing partial pressure of nitrogen in the treatment gas.