3D finite element simulation of hydrogen diffusion in 16MnR steel weldment

Hydrogen diffusion coefficients in weld metal, heat affected zone (HAZ) and base metal of the 16MnR steel weldment are determined by using electrochemical permeation technique. A 3D sequential coupling calculating method on hydrogen diffusion is developed based on the finite element code-ABAQUS. The effects of welding residual stress and microstructure on the hydrogen diffusion are taken into account. The hydrogen concentration versus time is obtained. The hydrogen concentration accumulation and welding residual stress is much larger in weld metal and HAZ, which will increase the cracking probability related to the hydrogen under the stress.