Showing papers by "DECHEMA published in 1974"

Corrosion of Metals in Organic Solvents

Abstract: Developments in the chemical and petrochemical industries, advances in chemical engineering, the introduction of new products, advances in the technology of intermediates, and problems in energy conversion have created new corrosion problems, involving the failure of metallic materials under the influence of aggressive organic solvents. Failures of this type lead not only to a deterioration of the mechanical properties of structural material, but also to discoloration and unwanted changes of the solvent. Since organic solvents in most cases are poisonous, inflammable, and, in the presence of air, explosive, the demands on the corrosion resistance of the materials used are immense. Therefore, in discussing corrosion of metals in organic solvents problems arise which have no parallel in the field of corrosion in aqueous media.

Zeitstanduntersuchungen an Nichteisenmetallen für den Apparatebau

Abstract: In einem Gemeinschaftsprogramm des Dechema-Fachausschusses „Werkstoffe und Konstruktion im Chemie-Apparatebau” werden seit einigen Jahren in Zeitstandzugversuchen 50 000 h-Werte fur Nichteisenmetalle erarbeitet. Neben technisch reinem Kupfer, Nickel, Aluminium und Titan sind verschiedene Legierungen dieser Basismetalle im Programm, soweit sie fur den Apparatebau interessant sind. Daneben lauft ein gesondertes Programm uber Blei und Bleilegierungen. Hier wird uber die abgeschlossenen Untersuchungen an SF-Kupfer, LC-Nikkel, Aluminium 99,5 und Titan Gruppe III sowie der Legierung NiCu 30 Fe berichtet, die in Form von glatten Proben wie auch im gekerbten Zustand und als Schweisverbindungen untersucht wurden. Die 1 %-Dehngrenze und die Bruchgrenze werden als Zahlenwerte fur 1000, 10 000 und 50 000 h sowie in ihrem Verlauf uber einen Temperaturbereich von 20 bis 650°C angegeben. Long Term Behaviour of non Iron Metals. In a teamwork of several laboratories the Dechema Specialist Committee „Materials and design in chemical engineering” investigates the long term behaviour of non iron metals over 50 000 hours. This programme comprises technically pure copper, nickel, aluminium and titanium as well as several alloys of these basic metals if relevant for chemical apparatus. Lead and some of its alloys are tested in a special research programme. This paper deals with the results found on copper 99.9, LC-Nickel 99.2, Aluminium 99.5, pure titanium and the Ni Cu 30 Fe alloy, which have been investigated in the form of unnotched, notched and welded specimens. 1 % creep limit and creep strength data are given for 1000, 10 000 and 50 000 hours as well as their dependence on temperature (between 20 und 650°C).

Über den Zusammenhang zwischen Lochkorrosion und Festigkeitsverhalten austenitischer Chrom-Nickel-Stähle

Abstract: Im Hinblick auf die spannungsmechanischen Wirkungen der Lochkorrosion werden die Lochform, die Lochtiefe und -grose sowie die Haufigkeit der Lochfrasstellen diskutiert, die unter potentiostatischen Bedingungen an den Stahlen X5CrNi 18 9 und X5CrNiMo 18 10 in 3% NaCI entstehen. Relations between pitting corrosion and mechanical strength of austenitic chromium nickel steels The shape, depth and size as well as the frequency of pits formed under potentiostatic conditions on the surfaces of chromium-nickel steels (German designations X 5 CrNi 18 9 and X 5 CrNiMo 18 10) in 3% NaCl are studied with reference to stress mechanical effects of pitting corrosion. Comparative studies of pitting corrosion and strength behaviour of specimens at- tacked under pitting enable the residual tensile strength to be represented as a function of potential, and the tensile strength as such to be plotted as a function of a corrosion index containing pit depth and number. External effects like thermal treatment, alloy composition and cold deformation can be interpreted uniformly on the basis of all these graphical representations.