Assessment on the Metallurgical and Mechanical Properties of SA 210 A1 Rifle Tubular Joints

Heat exchangers tubes in critical thermal power plants and waste heat recovery boilers are typically made of SA 210 A1 ferritic steels operated in the temperature range of 300-400 °C. In this study, an attempt has been made to investigate the weldability of SA 210 A1 rifle tubular steel using Gas Tungsten Arc (GTA) welding technique employing ER70S2 filler wire and Shielded Metal Arc (SMA) welding technique using E7018 electrode. Comparative studies were performed to investigate the effect of welding process on the metallurgical and mechanical properties of these weldments. Microstructure studies inferred the formation of Widmanstatten ferrite and ferrite- cementite matrix (alternate lamellas) at the heat affected zone in both the weldments. Tensile studies confirmed that the GTA weldments have better mechanical properties compared to the SMA weldments. A detailed structure - property relationship has been made using the combined techniques of optical and SEM microscopy.