THE INITIAL SURFACE PRODUCTS FORMED ON HIGH TEMPERATURE FE - CR - NI ALLOYS IN CARBURIZING ATMOSPHERES CONTAINING SMALL PARTIAL PRESSURES OF OXYGEN
The very initial stages of corrosion of a range of Fe-Cr-Ni model and commercial austenitic alloys and of a pure binary 50Cr + 50Ni alloy exposed at 1098 K to a carburizing atmosphere with a partial pressure of oxygen 10**-30 bar have been studied. Experiments used electropolished and cold-worked specimens and these were exposed in a corrosion rig and also in a small specially constructed reaction cell installed within an S-ray photoelectron spectrometer. The nature of the corrosion products, their population and distribution during heating to temperature and at reaction temperature were determined using X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. A comparison of the results from the model and commercial alloys clearly delineates the influence of minor alloying additions on carbide growth. Silicon and manganese do not enter into carbide formation but remain in oxidized form. The SiO-2 layer acted to suppress carbide growth by blocking both the outward transport of metal and the inward transport of carbon.
Bibliographic Reference: "PHYSICS OF OXIDATION", OXFORD (UK), APRIL 1-3, 1985 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 32133 ORA
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Record Number: 1989123081800 / Last updated on: 1987-01-01
Available languages: en