Study of Mechanical Properties and Chemical Composition of Railway Weld Joint

Abstract

This research compared two brands of thermite powder to determine the most suitable one for use in the welding railway joint. The chemical composition of two thermite powder brands was determined using X-Ray Diffraction and Atomic Absorption Spectrometry. After welding, the specimen joint was cut in half, and one half underwent stress relief treatment while the other was characterized as it was. Hardness, tensile test and metallurgical structures were observed. The results showed that the thermite powder type A provides a harder weld and greater tensile strength than type B. This analysis showed that perlite and ferrite phases were found in both samples. Overall, our results showed that both thermite powder brands provide mechanical properties, microstructure and chemical composition within the acceptable range of the State Railway of Thailand. The thermite powder brand A was, however, able to provide higher quality and better welding ability than brand B which caused more porosity and cavitation in the weld than brand A. Brand B is 100 baht per kilogram cheaper than A.