Hydrogen effect on structure and properties of casting titanium alloys VT5L, VT21L, VT14L

The effect of hydrogen in the concentration range from 0.004 to 0.06% on the structure and properties of casting titanium alloys was investigated during tensile and impact testing over the temperature range from 20 to 60 deg C. The alloy structure was studied by means of metallographic, microfractographic, and X-ray structural analyses. It is shown that with a decrease in testing temperature the trend of the VT5L, VT21L, and VT14L alloys toward hydrogen brittleness increases. The maximum permissible hydrogen concentration in the temperature range investigated is 0.-0.2% for the alloys VT5L, and VT21L. For the alloy VT14L the hydrogen concentration does not exceed 0.01%, since at this value the yield limit shows a fall