Determination of Diffusable Hydrogen in Duplex Stainless Stell Welds

Authors: RAMAZAN KAÇAR

Abstract: The risk of hydrogen cracking in steel welds depends on a number of interrelated factors, the most important of which is the hydrogen content that originates from the welding consumable. In designing a welding procedure to avoid cracking, it is necessary to define the hydrogen level associated with a given welding consumable, using standard methods. In this study, the Oerlikon/Yanaco hydrogen gas analysis method, which is widely used to determine the hydrogen content of ordinary ferritic steel welds, was modified, and thus the time-temperature relationship of hydrogen evolution from duplex stainless steel weld metal at 200, 400, 600 and 950^oC was investigated experimentally and determined theoretically on the basis of BS 6693 samples. It was found that diffusible hydrogen evolution from weld metal heated at 400^oC for 24 hours was completed experimentally and theoretically. In conclusion, the diffusible hydrogen amount which is potentially hazardous in the long term in duplex stainless steel weld metal can be easily determined by modification of the Oerlikon/Yanaco methods.

Keywords: Duplex stainless steel, Diffusion of hydrogen, Hydrogen measurement, Oerlikon/Yanaco methods

Full Text: PDF