Development of Improved Equations for Weld Heat Input and Dilution Control: Part 2

This report introduces techniques involving novel calculation methods developed by the Electric Power Research Institute and Bechtel Marine Propulsion Corporation [1] that can be used to develop an improved understanding of welding factors affecting substrate weld heat input and dilution. These improved calculation methods are especially warranted in ASME BPVC Section XI repair and replacement welding activities such as mitigation of hot cracking (dilution control) and optimization of temper bead welding (heat input control). Various parameter sets are tested to demonstrate the effectiveness of the new calculation methods and how they can be refined in future studies to further improve accuracy. Additionally, this report highlights the limitations associated with the ASME BPVC Section IX theoretical heat input and power ratio calculation methods widely used in the welding industry for control of substrate heat input and weld dilution. Weld trials are performed in this study to demonstrate the limitations and determine proper precautions to take when using the calculation methods.