Hydrogen embrittlement has been studied in continuous cast sheet of a Ni 3 Alalloy (NI 77.83 AL 21.73 ZR 0.34 B 0.1), known as IC-50, after introducing various amounts of hydrogen cathodically. The elongation and UTS decreased with the increasing content of hydrogen. When tensile-tested at a strain rate of 5.8 × 10−5 s−1, the elongation decreased from 32.7% for no charging to 1.9% for 330 min of charging with 50 mA cm−2 current. The yield stress, however, did not change. When tested at a higher strain rate of 5.8 × 10−3 s−1, the embrittlement was less, but the yield stress increased with the hydrogen content. With increasing hydrogen content the fracture mode changed from dimpled to intergranular and cleavage modes.