سعيد صميمي

fastening is one of the main elements of the structure of railway lines, whose main task is to maintain the stability of the line, and its damage causes a significant increase in the maintenance of the line. One of the problems created for fastening is corrosion due to various reasons. In this thesis, in order to investigate the effect of corrosion on the deterioration of fastening after examining various standards, while examining the national standard of Iran - Corrosion of metals and alloys - Corrosion tests in artificial atmospheres - Recommendation for accelerated tests to eva‎luate product quality and also the national standard of Iran 10315 and BS EN 13146-6:2012 standard was used to build a salt spray corrosion simulator. After examining the fastening subjected to corrosion simulator conditions and the effects of corrosion on the fastening springs in order to investigate the effect of corrosion on the deterioration of the fastening, different tests and experiments were conducted, including the longitudinal resistance test of the fastening, the lateral resistance test of the bindings, the vertical resistance test, the XRD test, And Vickers microhardness test was done. Also, in order to investigate the combined conditions of corrosion and fatigue, a number of fastening (both fastening subjected to corrosion conditions and new fastening) have also been subjected to fatigue conditions. The results of the mentioned tests show a decrease in the Vickers microhardness of fastening under corrosion conditions by 15%, a decrease in the longitudinal resistance of fastening under corrosion conditions by 14%, and a decrease in the lateral resistance of binders under corrosion conditions by 10%. It should be noted that during the fatigue test, the permanent vertical displacement was measured for all types of fastening, and the displacement was almost the same for all types of bindings tested, therefore, the main purpose of the fatigue test was to put the bindings subjected to corrosion under fatigue conditions to the conditions Corroded binders should also be examined after fatigue.

پابند , خوردگي

fastening , corrosion

Saeed Samimi

Dr. Masood Nasr Azadani