EFFECTS OF KR POSTBOMBARDMENT ON CARBONITRIDES PRODUCED IN A LOW-CARBON NITROGEN-IMPLANTED STEEL

The effects of Kr post-bombardment on carbonitrides produced by N-impl antation in a low carbon steel are studied by means of conversion elec tron Mossbauer spectroscopy, nuclear reaction analysis and Rutherford backscattering technique. The results show two main features: dissolut ion and reprecipitation of the produced carbonitrides and modification of the thermal behaviour of the precipitates. Recently we have perfor med similar experiments bombarding samples of the same steel with He a nd Ar. Comparison of the experiments shows that irradiation with Ar or Kr ions provides the best retention of carbonitrides at 450-degrees-C . On the other hand irradiation with Kr ions to the same dpa level is most effective in producing the dissolution and reprecipitation proces s.