Study of Hydrogen Diffusion in SAF 2507 super duplex stainless steel by internal friction method
Hydrogen Snoek relaxation peaks were found on temperature dependencies of low-frequency internal friction of hydrogen-charged SAP 2507 duplex stainless steel. The values of activation enthalpies of elementary diffusive jumps of hydrogen in the lattice of austenite phase have been obtained from the frequency shifts of temperature positions of the peaks for a number of microstructural states of SAF 2507. Activation enthalpy of hydrogen diffusion in wrought SAF 2507 is equal to 0.55 eV and decreases to 0.46 eV after ageing at 800 degrees Celsius for 2hrs. The kinetic curves of hydrogen accumulation in austenite phase of SAP 2507 duplex stainless steel after electrolytic hydrogen charging have been obtained. Numerical analyses of these curves allowed estimating the values of coefficients of hydrogen diffusion in the ferrite and austenite phases of SAF 2507 duplex stainless steels. These values are equal to 1.1x10(-13) m(2)/s and 1.0x10(-15) m(2)/s for ferrite and austenite phases of wrought SAF 2507 DSS, and to 2.5x10(-13) m(2)/s and 1.6x10(15) m(2)/s for P/M HIP SAF 2507 DSS, respectively. Obtained values of diffusion coefficients are compared with earlier results.
Bibliographic Reference: Oral report given at: The 6th World Conference and Expo: Duplex 2000. Organized by: Associazione Italiane Mettallurgia. Held at: Venezia (IT), 17-20 October 2000
Record Number: 200013203 / Last updated on: 2001-03-23
Original language: en
Available languages: en