Abstract
We investigate the impact of boron against hydrogen segregation into prior austenite grain boundaries in martensitic steels using thermal desorption spectrometry (TDS) and ab initio calculations. While both boron and hydrogen are attracted to grain boundaries (GBs) in iron, the interaction between boron-doped GB and hydrogen becomes repulsive. Such an effect has been observed experimentally using TDS measurements, with the disappearance of one peak when boron is incorporated into the microstructure. It indicates an improved resistance of the microstructure against hydrogen embrittlement, which is confirmed through slow-strain-rate tensile tests of hydrogen-charged boron-doped and boron-free steels.