Computer — Aided Determination of Diffusible Hydrogen in Deposited Weld Metal

Abstract

The vacuum method is described and compared with other methods for the determination of diffusible hydrogen in deposited and fused weld metal. It is shown that the vacuum and mercury methods are practically equivalent. A calculation method to reduce the time of determination of diffusible hydrogen in deposited weld metal is proposed. It uses measurements at the beginning of the hydrogen effusion. The functional-analytical solution to the direct 3D hydrogen diffusion problem for a parallelepiped-shaped solid is found. The inverse problem for unknown initial concentration of hydrogen introduced through a deposited metal is stated and solved numerically. It is demonstrated that as much as a quarter of total diffusible hydrogen can effuse prior to its measurement according to the standard procedure. The proposed method allows the time of determination of diffusible hydrogen to be reduced by several factors.