Abstract
Electrodeposition of metals on steel is accompanied by hydrogen evolution and can lead to the absorption of hydrogen by the steel substrate, which can result in hydrogen embrittlement.
In the present study, the hydrogen uptake during standard zinc and copper electrodeposition processes is studied. High strength steels(HSS) with yield strength levels of 800 and 1000 MPa are coated. After the electrodeposition process of zinc and copper, the diffusible and the total hydrogen amount are determined by hydrogen analysis. Furthermore, the time dependent behavior of hydrogen permeation at room temperature is studied.
The hydrogen balance of the deposition process was made by calculating the total amount of hydrogen electrochemically produced and the total amount of hydrogen permeated through the steel during the electrodeposition process.
It is shown that the hydrogen absorption as well as the hydrogen permeation characteristics for the two deposition processes deviate significantly from each other. A difference in hydrogen uptake by the electrodeposition process (zinc/copper) can be seen for the two different substrate materials. The majority of the permeable hydrogen is located inside the zinc/copper coating. In addition, the diffusible hydrogen content depends on the microstructure of the steel substrate.
The final aim of this work is to evaluate new electrodeposition processes for HSS and to optimize the electrodeposition parameters in order to achieve metallic coatings on HSS with reduced risk for hydrogen embrittlement.