The Study of Fatigue Failure Performance of Vehicle Metal Structures Used in Transportation of Corrosive Materials

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 mаchine 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 (GOST 2651:2005; DIN 17100) and quality steels -10 Steel, 15 Steel, 20 Steel, 25 Steel (GOST 1050-88; DIN 17200) 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.

Assessment of the Influence of Corrosive Aggressive Cargo Transportation on Vehicle Reliability

“…We choose nitrophoska as the corrosion environment due to its chemical composition, for which it refers to complex fertilizers and allows you to explore the joint impact of chlorides, sulfates and nitrates corrosion material agricultural machines. The cases of loading the vehicle in air and in the environment of nitrophoska solution are studied by values [3][4][5][6][9][10][11][12]. The calculation is made applying (15).…”

“…are found to be the most susceptible to corrosive influences [4][5][6]. Considering the positive trend of agrarian production development in Ukraine and around world [7] and the growth of volumes of fertilizer transportation -up to 2% of cargo turnover [7,8], it is expedient to take into account the influence of such environments on the vehicles [9][10][11][12][13][14]. The presence of fertilizers greatly reduces the reliability of metal structures [1,3,4,[10][11][12][13][14].…”

“…The corrosion-fatigue surface cracks develop to critical sizes [8-13,], causing a significant decrease in the service life of the transport vehicles structural elements. Aggressive working environments greatly accelerate the nucleation of cracks, and this fact must be taken into account when evaluating longevity [5,[9][10][11][12][13][14][15][16].…”