Microstructure and metallurgical property investigation of welded IRSM 41-97 rail steel joints

Abstract

IRSM41-97 rail steel is a type of structural steel which is highly resistant to atmospheric corrosion. It is a low carbon steel having less than 2% of carbon and other alloying elements like Cr, Cu, Ni, Si, Mn, S and P less than 2%. It is a HSLA structural steel primarily utilised in the railway industry for the construction of railway coaches, bridges, and frame building constructions, wagons, support structures etc. IRSM41-97 rail steel can be welded using GTAW and GMAW welding technique. The common industrial copper coated ER70S-6 Filler wire is used to weld IRSM41-97 rail steel for railway applications. During welding, the metallurgy of the IRSM41-97 rail steel completely changes due to the high heat dissipated during welding and improper selection of process parameters and not choosing the right filler material resulting in losing its properties. Autogenous gas tungsten arc welding (AGTAW) is a no-filler welding operation which is appropriate for low heat input (Q), longer weld times, and high weld speeds. In this research AGTAW IRSM41-97 rail steel weld joints from 2 mm thick plate is prepared as per ASTM standards and the metallurgical properties are investigated by carrying out macro structural and micro structural investigations. This research leads to widen the application of IRSM41-97 rail steel not only in railway sector industry as well as other industrial sectors.