Radavich, John F.
Research Associate in Physics, Purdue University, Lafayette, Ind.
Pages: 26 Published: Jan 1955
Corrosion investigations on ferritic stainless steels have shown that initial oxidation takes place by the formation of a thin oxide substrate on which nodules of oxide nucleate and grow (1). Extensivepreliminary work sponsored by the International Nickel Co. on high-temperature oxidation of austenitic alloys heated at 815 C showed that a similar growth phenomenon takes place on most of the common austenitic alloys but differs in the case of the complex high-temperature alloys N-155 and Hastelloy C (2). Under the sponsorship of the International Nickel Co. and under the direction of V. N. Krivobok and C. R. Mayne, a project was undertaken to study the initial oxidation of various high-temperature alloys, using electron microscopy, reflection electron diffraction, transmission electron diffraction, X-ray diffraction, and X-ray spectrography. Because the oxidation process can be studied for much longer times at the lower temperatures and in view of corrosion data obtained at 600 C, the majority of oxidation studies were carried out at this temperature; however, data of oxidation carried out at 815 C will also be included. This paper will describe the various techniques used in the course of the investigation and present the results of oxidation of seven high-temperature alloys. The experimental work will be divided into two sections. Section I will deal with a detailed study of the initial oxide growth on the alloys by means of electron microscopic examination of surface replicas and stripped oxide films. In this section, electron microscopic studies of the oxide growth occurring on one region after repeated oxidations will be presented for the N-155 and a typical iron-chromium-nickel alloy. Section II will deal with the analysis of the structures and the identification of the oxide films formed on the seven alloys.
Paper ID: STP46833S