Study on determination of hydrogen in titanium and titanium alloys

Abstract

As hydrogen in titanium and alloys is considered an undesirble impurity, determination is, a matter of importance. In this paper a method and apparatus for the determination of hydrogen in titanium and titanium alloys by vacuum fusion, vacuum extraction and combustion method are reported. The vacuum fusion method is one of the standard ones but its apparatus is compilated and requires skilled operation. The vacuum extration method is simple, rapitd and allowably complet.By the combustion method, the sample is burned in oxygenin a high frequency combustion fuenace and the gas is passed through hot copper oxide to ensure complete oxidation of hydrogen to water which is absorbed in a phosphorous pentoxide absorption tube.Applying the vacuum extraction method, the content of hydrogen of commercially pure titanium and titanium alloys was measured.The results obtained are as follows:(1) The evolution of hydrogen from titanium is easy and the variation of diameter of the specimen is affected when it is of bar shape.(2) It is found that the hydrogen content of titanium ingot has something to do with the hardness (probably exygen content).(3) A little higher hydrogen content is obtained in the centre and bottom part of titaniumm ingot.(4) Also, a little higher hydrogen content is obtained in the titanium sheet and bar than the titanium ingot.(5) Hydrogen content of the titanium sheet and bar can be regurated by the method of treatment.(6) When titanium is dipped in the nonoxidizing acid such as HCl or H2SO4, the hydrogeon content in the specimen is increased remarkably.(7) So high hydrogen content of titanium and titanium alloy as to affect the charpy impact value is not obtained.