Hydrogen embrittlement of amorphous alloys based on iron and nickel

Abstract

Hydrogen embrittlement of amorphous alloys based on iron and nickel was examined in constant extension rate tests during cathodic polarization. Tests were carried out at a current density of 50 A·m −2 in 0.1 M H 2SO 4 with and without addition of NaAsO 2 and NaCl. Hydrogen permeation and polarization curves were measured. Differences in the degree of hydrogen embrittlement were ascribed mainly to differences in the entry of hydrogen into the alloys. It was suggested that a low degree of embrittlement resulted largely from a hindrance of hydrogen entry. For alloys containing phosphorus, this might be associated with phosphorus-containing oxyanions and salts. For the alloy with higher silicon content it may be associated with the formation of oxides of silicon.