Hygroscopic behaviour of certain basic‐coated electrodes in a wet tropical climate

Abstract

Summary The study of the wetting kinetics after baking of basic electrodes in a wet tropical climate is important since the water which they contain is the main source of atomic hydrogen which enters into the metal during arc welding, and it is also the origin of multiple defects appearing in the metal deposited. A calculation method is established for evaluating the kinetics of moisture absorption into the coatings of basic electrodes exposed to a wet tropical climate, based on solving Fick's diffusion equation for an adequate system geometry and suitable boundary conditions. This allows evaluation of the effective diffusion coefficients, the critical exposure times for different environmental conditions, and also assessment of electrode packaging and storage conditions.