Rectangular samples obtained from the EDD steel plates were polished and then annealed for stress-relieving at 450°C in an argon atmosphere. Subsequently hydrogen was charged electrochemically into the samples in a 0.1N H₂SO₄ medium having 10 mg/lit. sodium arsenide as hydrogen recombination poison (enabling higher hydrogen ingress into the alloy). The charging conditions were varied to change the hydrogen input into the samples. The RMS voltage of the corresponding MBE was measured.

The RMS voltage was correlated to the charging conditions, that is the hydrogen input into the samples. Remarkable changes in the frequency domain analysis were observed due to hydrogen charging. Taking into consideration the complex interaction of hydrogen with the magnetic characteristic of materials, the results were explained. The changes in internal stress, increase of pinning centres for domain wall movement and alteration in the magnetic exchange interaction due to hydrogen were considered in the analysis. It is felt that such micromagnetic techniques have substantial potential for hydrogen embrittlement and hydrogen interaction studies in steels and other ferromagnetic materials.