ISSN:
0947-5117
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Description / Table of Contents:
Investigation of corrosion in the development of decontamination solutions for nuclear systems - Part III: The corrosion behaviour of ferritic steels with different carbon contents in formic acid-formaldehyde solutions with and without inhibitorsIn decontamination solutions of the type formic acid-formaldehyde, ferritic steels undergo heavy pitting corrosion or shallow pitting corrosion. The addition of formaldehyde to formic acid solutions scarcely influences the temperature dependency of the corrosion rates, the solution specific corrosion rates, however, increase with increasing carbon content of the steels.The high corrosion rates, especially of the steel 21 CrMoV 5 11, can be reduced by about two orders of magnitude by adding inhibitors as thiourea, ethyl thiourea, and phenyl thiourea to the formic acid-form-aldehyde solutions, but pitting corrosion is unavoidable.
Notes:
Dekontaminationslösungen vom Typ Ameisensäure-Formaldehyd verursachen an ferritischen Stählen starke Mulden- bzw. Lochkorrosion. Die Temperaturabhängigkeit der Massenverlustraten wird durch den Formaldehydzusatz zur Ameisensäure kaum beeinflußt, hingegen steigen die lösungsspezifischen Massenverlustraten mit zunehmendem Kohlenstoffgehalt des Stahles stark an.Mit Inhibitoren, wie Thioharnstoff, Ethylthioharnstoff und Phenylthioharnstoff, lassen sich die hohen Massenverlustraten besonders von 21 CrMoV 5 11 um rund zwei Größenordnungen senken, die Lochbildung aber nicht vermeiden.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/maco.19880390704
