Corrosion-fatigue failure of tractor trailers metal materials in aggressive environments

Abstract

The processes of corrosion-fatigue failure of materials in contact with mineral fertilizers are insufficiently studied. As a result of joint influence of atmospheric corrosion and mechanical loads, about 70 to 80 % of machine parts get out of order, 20 to 25 % of which are failures caused by operating overload due to the strength loss because of atmospheric corrosion. A large part of metal structures of agricultural vehicles used to transport mineral fertilizers is under the direct influence of aggressive environments and dynamic loads that occur during the motion by field roads. Saturated solutions of the most aggressive working environments used in agricultural production, in particular ammonium sulphate and nitrophosphate are investigated to reduce fatigue resistance of ordinary steels groups – St3 and St5 and quality steels – 10 Steel, 15 Steel, 20 Steel, 25 Steel when loaded at all levels. The fatigue endurance limit decreases in comparison with air up to 2.02 times in a solution of ammonium sulphate, and to 2.32 times in a solution of nitrophosphate. In organic fertilizer environments, compared to distilled water, the conditional fatigue endurance limit increased to 9 %. The properties of the given materials as an inhibitor of corrosion-fatigue failure were discovered and proved.

Agricultural Machinery Corrosion

“…The relative ratios of the essential plant nutrients can influence the corrosiveness of compound liquid fertilizers, there being some evidence that the greatest effects occur with fertilizer solutions containing about 15% nitrogen, especially when half the free nitrogen is derived from urea and half from ammonium nitrate. Some typical reactions for liquid fertilizers are given in Table 3 [25].…”

Determination of Thermomechanical Stresses in Elements of Vehicles' Braking Systems

“…The constant influence of these factors' combinations causes damages with subsequent destruction. The most typical damages are fatigue damage, thermomechanical damage, corrosion-mechanical wear, corrosion fatigue, corrosion cracking [17][18][19][20][21]. Fatigue fractures cause spontaneous failure of metal structures of vehicles' components and elements, lead to weight loss, intensify wear of joints, change the amount of surface roughness of parts, reduce fatigue strength and initiate cracks.…”