TWI Industrial Member Report Summary 658/1998
L S Smith and M F Gittos
Titanium and its alloys (weldments and parent materials) can suffer degradation of mechanical properties in the presence of hydrogen, either in the surrounding environment or absorbed in the material. For example, these materials are prone to hydrogen-induced porosity on fusion welding. There is currently much conflicting advice given on measures necessary to avoid porosity formation and a review of current data and experience would be of benefit to all involved with titanium fabrication.
Further, titanium and its alloys tend to form hydrides at relatively low hydrogen concentration. Hydride induced cracking in the heat-affected zone (HAZ), due to the uphill transport of hydrogen to these regions, was responsible for the failure of a Saturn launch vehicle in 1964.