Inspectioneering
Inspectioneering Journal

99 Diseases of Pressure Equipment: Titanium Hydriding

By John Reynolds at Intertek. This article appears in the September/October 2005 issue of Inspectioneering Journal

Titanium (Ti) hydriding is another somewhat unusual metallurgical degradation phenomena that can result in brittle fracture. Unlike many other steel embrittlement phenomena, this one most often occurs in thin wall Ti tubes that have been selected for their superior corrosion resistance of overhead condensers.

In certain pH ranges and under some galvanic corrosion conditions above 165oF (75oC), hydrogen penetrates the Ti tube and reacts to form an embrittling hydride phase. It can also occur when iron has contaminated the surface of the titanium tube, thus, promoting a galvanic couple that drives hydrogen into the Ti tube. So, fabrication and repair cleanliness are vital to the avoidance of titanium hydriding. The hydriding reaction may continue until there is a complete loss of ductility, and any form of transient stress can fracture the tubes. Those stresses may occur from upset process conditions or during bundle removal or repairs. Like so many other metallurgical embrittling phases, there may be no reliable inspection techniques to detect titanium hydriding, though some claim to be able to detect it with specialized eddy-current techniques. Typically, an owner-user finds out that their Ti tubes are hydrided by experiencing leaks or cracks. If there is doubt, a tube can be pulled and crushed in a vice to see if it results in a ductile or brittle fracture.

A related phenomena in titanium is metal ignition, which will be covered separately. But in one case, significant Ti hydriding was thought to be a potential contributor to the metal igniting and burning.

Do you have titanium condensers inservice that may be susceptible to titanium hydriding?


Comments and Discussion

There are no comments yet.

Add a Comment

Please log in or register to participate in comments and discussions.


Inspectioneering Journal

Explore over 20 years of articles written by our team of subject matter experts.

Company Directory

Find relevant products, services, and technologies.

Job Postings

Discover job opportunities that match your skillset.

Case Studies

Learn from the experience of others in the industry.

Event Calendar

Find upcoming conferences, training sessions, online events, and more.

Industry News

Stay up-to-date with the latest inspection and asset integrity management news.

Blog

Read short articles and insights authored by industry experts.

Acronyms

Commonly used asset integrity management and inspection acronyms.

Asset Intelligence Reports

Download brief primers on various asset integrity management topics.

Videos

Watch educational and informative videos directly related to your profession.

Expert Interviews

Inspectioneering's archive of interviews with industry subject matter experts.