Zkoušení konstrukčních ocelí a jejich ochrana vůči vlivům atmosféry na koksovně

Abstract

Research thesis deals with the effects of accelerating atmospheric corrosion, possibilities of monitoring and ways of anticorrosion protection for structural steels. Thesis describes the levels of air pollution and subsequently classified them according to degree of aggressiveness from C1 to CX. The attention is also paid to the characteristics of selected types of the steel and local sources of pollutions which influence structure of "Coking plant Svoboda" atmosphere. Following is explained the way of steel testing and surface protection directly on coking plant. Experimental part of thesis is focused on testing of selected construction steel EN S235JRG1 (ČSN 41 1373, C17), EN S355J0WP (ČSN 41 5127, Atmofix B) and EN X6CrNiMoTi17-12-2 (ČSN 41 7348) taken from metal sheet directly in coking plant condition and tested in VŠB-TU corrosion laboratory. The corrosion rates were determined and compared on tested steels based on gravimetric method. It was found out low level of Atmofix B (15 127) and carbon steel (11 373) corrosion resistance in wet environment with carbon dioxide under condensation chamber test and in parallel impropriety of use Atmofix B in environmental with chloride according salt spray test. Stainless steel (17348) was resistant in tested conditions. Character of the attack was detected by metallographic analysis and higher rate of corrosion of steel 11373 against steel 15127 was confirmed in coking plant area. Its usage is recommended in combination with protective Amerlock 400C coating which has proved to be suitable to the Coking plant Svoboda environment.