Patent ID: 6873672

Claim:
Method of measuring the resistance to hydriding of tubes and tubular claddings, meaning hydriding the formation of hydrides, characterized by the following steps: inserting a tube to be tested through a chamber of ultra-high vacuum equipment, said chamber containing a mass spectrometer and a total pressure gauge; passing hydrogen gas or a gas mixture of hydrogen and inert gas(es) into the interior of the tube, the permeation of hydrogen through the tube wall causing hydriding of the material thereof; heating said tube by Joule effect heating means; detecting hydrogen which has permeated through the wall of the tube at the exterior of the tube by measuring H 2 and H partial pressures in the chamber or by measuring the total pressure in the chamber and determining a permeation time on the basis of a permeation curve, i.e. a curve of quantity of hydrogen detected by measuring H 2 and H partial pressures in the chamber against time, or total pressure detected against time, said permeation time being a time obtained from said permeation curve and representing the first appearance of hydrogen exterior of the tube, and; detecting a sudden rise in the total pressure, as an indication of the time of appearance of a first micro crack in the tube.