EFFECT OF HYDROGEN ON ANISOTROPY OF MECHANICAL-PROPERTIES OF VT6CH TITANIUM-ALLOY AT CRYOGENIC TEMPERATURES

The effect of hydrogen on the mechanical properties of VT6Ch titanium alloy was studied at 293, 196, 77 and 4 K using longitudinal and trans verse specimens cut from 2 mm thick sheet and 18 mm thick plate. The s trength properties were found to increase 2 to 2.4 times with temperat ure decreasing from 293 to 20 K, then decrease somewhat at 4 K (except ultimate tensile strength of plate). The plastic properties of the al loy remain at adequate levels down to 77 K. With test temperature decr easing from 196 to 4 K the anisotropy of the mechanical properties inc reased. At all test temperatures and hydrogen concentrations (from 0.0 03 to 0.1 wt.%) the ultimate tensile strength of longitudinal specimen s exceeded that of transverse specimens. The alloy studied revealed bu t a moderate tendency to hydrogen embrittlement during tensile and imp act strength tests.