Hydrogen-enhanced stress corrosion cracking and corrosion fatigue of HSLA steels in sea-water

• Autorzy: Ćwiek J.
• Języki publikacji: EN

Abstrakty

EN

Hydrogen degradation of extra high strength weldable steels bas been evaluated under static and cyclic tensile loads in sea-water at room temperature. Two quenched and tempered steel grades and their submerged arc welded (SAW) and shielded metal arc welded (SMAW) joints were examined. Slow strain rate tests (SSRT) on cylindrical smooth specimens, in air and artificial sea-water were performed. Tests in sea-water were conducted under cathodic polarisation with constant current densities. Relative values of: fracture energy, time to failure, elongation, reduction in area and tensile strength were chosen as measures of hydrogen degradation. Low-cycle corrosion fatigue tests were performed on cylindrical smooth specimens. Sinusoidal wave form uniaxial tension loading under strain control was carried out. Fracture modes were investigated with the use of a scanning electron microscope (SEM). Polarisation curves in artificial sea-water for brie metals with the potentiostatic method were obtained. Additionally, polarisation curves for selected areas of welded joints were established with the use of a microcell and the potentiodynamic method. Hydrogen permeation through brie metal, heat affected zone (HAZ), and weld metal were measured by means of conventional Devanathan-Stachurski method. Hydrogen diffusivity and content of diffusible hydrogen were established. Observed decrease of relative values of degradation parameters with the increase of current density exhibits a certain minimum. The loss of plasticity was as high as 70-90% for brie metals and welded joints. Further increase of current density does not cause higher degradation. Significant reduction of a fatigue life time (40-50%) due to hydrogen absorption was also observed.

Słowa kluczowe

EN

corrosion fatigue; high-strength low-alloy steel; hydrogen embrittlement; sea-water; stress corrosion cracking; welded joints

• Wydawca: Politechnika Gdańska
• Czasopismo: Advances in Materials Science
• Rocznik: 2003
• Tom: Vol. 3, nr 1(3)
• Strony: 5--17
• Opis fizyczny: Bibliogr. 9 poz., rys., tab.

Twórcy

autor

Ćwiek J.

• Gdańsk University of Technology, Faculty of Mechanical Engineering, Poland

Bibliografia

• 1. Ćwiek J., Stale spawalne o wysokiej wytrzymałości. Przegląd Mechaniczny, 1996 (9), 9-15.
• 2. Eliaz N., ShacharA., Tal B., and EliezerD.: Characteristics of Hydrogen Embrittlement, Stress Corrosion Cracking and Tempered Martensite Embrittlement in High-Strength Steels, Engineering Failure Analysis, 2002 (9), 167-184.
• 3. Hydrogen Degradation of Ferrous Alloys, Oriani R. A., Hirth J. P., and Śmiałowski M. Eds., Noyes Publ. Park, Ridge, USA, 1985.
• 4. M. Śmiałowski: Hydrogen in Steels, Pergamon Press, Oxford, 1962.
• 5. Zieliński A.: Niszczenie wodorowe metali nieżelaznych i ich stopów. Gdańskie Towarzystwo Naukowe, Gdańsk, 1999.
• 6. Birnbaum H. K., Robertson I. M., Sofronis P., and D. Teter: Mechanisms of Hydrogen Related Fracture. A Review, Proc. 2nd Int. Conf. Corrosion Deformation Interaction, The Institute of Materials, London 1997, 172-195.