Vodíkové zkřehnutí DP ocelí

Abstract

In this diploma thesis, there is described the influence of hydrogen on mechanical and plastic properties of double phase steel DP600 using SSRT tests on the samples, which were provided in the longitudinal directions relative to the rolling direction. The samples were electrically hydrogenated during 4, 8 and 24 hours at a current density of 1 mA/cm2 and 5 mA/cm2 in a solution of H2SO4 with the addition of 1 g of KSCN as hydrogen poison. The samples after electrolytic hydrogen charging showed a relatively large decrease in ductility, which was used to calculate the index of hydrogen embrittlement. The fractographic analyses of non-charged and hydrogen charged tensile tests was performed by scanning electron microscope fracture to investigate the interaction effect of hydrogen and matrix on fracture surface morphology. Finally, electrochemical permeation was performed to determine the diffusion coefficient of hydrogen in DP600.