Comparison of Weld Built-up by FCAW and MIG Welding on Damaged Low Cr-Mo Alloy Steel Tube in Boiler Application

Abstract

In boiler application low Cr-Mo tubes are being used and in manufacturing or working these tubes are getting damaged. ASTM and ASME BPVC (Boiler Pressure vessel code is allowing wall thinning of tubes by 10%. Any damage more than 10% of wall thickness is causing rejection of Tube. As ASTM and ASME has provision for weld build-up on defected or damaged portion of Boiler Tubes, hence I am going to compare two welding process for the weld built-up on low Cr-Mo alloy steel tubes. In current practice the damaged tubes are being scrapped in boiler manufacturing as well as in running boilers. After this demonstration we can compare mechanical Properties of reworked tubes with original one. The Two methods adopted are MIG Welding and FCAW. Metal Inert Gas (MIG) welding is known for high deposition welding technique will minimum defect possibility. Flux Cored Arc Welding also has high weld deposition rate with minimum defect possibility.