High temperature behaviour of yttrium implanted pure iron and extra low carbon steel

High temperature behaviour of yttrium implanted pure iron and extra low car bon steel were analyzed at T = 700 degrees C and under oxygen partial press ure P-O2 = 0.04 Pa for 24 h to show the benefit of yttrium incorporation to the improvement of the implanted sample corrosion resistance at high tempe rature. Compositions and structures of yttrium implanted and unimplanted sa mples were investigated prior to high temperature oxidation studies by seve ral analytical and structural techniques (RBS, RHEED and XRD) to observe th e initial yttrium implantation depth profiles in the specimens. High temper ature oxidation tests performed by thermogravimetry and by in-situ high tem perature X-ray diffraction were carried out with the same experimental cond itions on yttrium implanted and unimplanted samples to have reference analy ses. The aim of this paper is to show the initial nucleation stage of the m ain compounds induced by oxidation at high temperature according to the ini tial sample treatment. The results obtained by in-situ high temperature X-r ay diffraction will be compared to those by thermogravimetry to show the ex isting correlation between weight gain curves and structural studies. Our r esults allow to understand the improved corrosion resistance of yttrium imp lanted pure iron and extra low carbon steel at high temperature. (C) 2000 K luwer Academic Publishers.