Dissimilar welding of SS 409 and Mild steel by Gas Tungsten Arc Welding (TIG) method by ER 309 L electrodes

摘要

The dissimilar material welding at lower expensive is one of the popular techniques which are used in power generation services such as mining, petro chemical refineries and mineral processing plant as well as recuperator in furnace system. For these applications, the insulation plays an important role for effective result. Fluid flow from one medium to another medium is carried out through insulation materials to prevent the transmission of excessive heat. If it gets wet, it will lose all its insulation properties. It can be easily crushed if the pipe gets stepped on. The materials serve an important character to save the heat energy in operating and constructing the power plant. In this research work, mild steel and stainless steel SS 409 are welded together by ER 309 L electrode by TIG welding process to achieve these applications. Service temperature is sensible while the inside temperature is maintained low because of rapid cooling. This research concluded that, insulation material is not necessary for dealing out the material (below 7000C). Stainless steel SS 409 tends to contract and expand more and it is a good corrosion resistant material at the service temperature. Mild steel is a good heat conductor; it cools quickly and contract earlier as the joint cools and the heat is removed from the metal surface.