Elastic constants of iron base sintered alloys after chemical heat treatment

In this paper is shown the effect of applied low-temperature gas nitrocarburizing on the elastic constants and mechanical properties of iron based sintered alloys. Low temperature gas nitrocarburizing (LTGNC) was carried out under laboratory conditions at T=550oC, and short saturation times of 15 and 30 min, respectively. The process was carried out in a laboratory shaft furnace with a volume of 2 dm3, in ammonia and carbon dioxide at an HN3/CO2=7.5/1 ratio. The elastic constants were determined using a standard dynamic methodology based on a pulse resonance method. Density and porosity of the samples were determined. A metallographic analysis of the microstructure after sintering and after chemical heat treatment was carried out.