Hydrogen diffusion model at welding high-strength steels

Abstract

Physical and mathematical models for hydrogen diffusion taking into account welded joint inhomogeneity in microstructure, temperature distribution, residual stresses, and reversible and irreversible traps of hydrogen are presented. The problem of diffusion is formulated with respect to the conditional potential of mass transfer and chemical potential. By the example of single-pass butt welding of 2.25Cr—1Mo high strength ferritic steel, the effects of welding consumables on diffusion processes are demonstrated. Utilization of austenitic consumables instead of ferritic ones leads to a reduction in hydrogen concentration in the HAZ by 3 times. The residual stresses affect slightly.

Keywords:

• Welding
• hydrogen
• diffusion
• solubility
• traps
• welding consumable
• residual stress
• high-strength steel