Methodology of hydrogen measurements in coated steels (Hppm) : final report

A valuable collection of more than 500 hydrogen articles was compiled into a searchable database including all articles as PDF files. Calibration of hydrogen analysers was studied for both procedures, gas and reference materials. Recommendations are given on how to proceed. A new electrochemical calibration method was developed and its performance is described in detail - including a novel feature, the effusion transient shaping. Details of the required cleaning steps and requirements for coating removal to avoid changes in the apparent hydrogen content are described in detail. In addition proper storage conditions were identified. The influence of each single parameter (weight, form, width, cleaning heating rate, heating programme, etc.) on the hydrogen content was studied to derive rules for high reproducibility, repeatability, accuracy, linearity, selectivity, specificity and robustness of melt and solid extraction. The limits of GDOES as an analytical tool were identified as well. Screening of local hydrogen analysis was performed by means of ToF-SIMS and nano-SIMS. Chemical charging in deuterated solutions has been identified as a powerful tool for the identification of the reaction mechanism and the diffusability of hydrogen in steel.