Abstract

The present survey is devoted to the investigation of a dangerous phenomenon (quite often observed in the process of arc welding) of the formation of hydrogen-induced cold cracks in welded joints of structural steels. We briefly analyze the existing models of the mechanism of hydrogen embrittlement. It is shown that difficulties in understanding the processes of initiation and growth of cold cracks are explained not only by the necessity of determination of the principal factors which govern the embrittling action of hydrogen but also by the absence of reliable knowledge of the microscopic mechanisms of fracture processes in metals. We suggest a new model of hydrogen embrittlement of metals with bcc lattice developed at the Paton Institute of Electric Welding. According to this model, atomic hydrogen adsorbed on the metal surface in the form of anions affects the surface energy of submicrocracks appearing in dislocation clusters in the process of deformation whose initial period of propagation obeys the classical Griffith scheme. The proposed model enables one to explain all known distinctive features of the cold cracking of welded joints and forms a groundwork for the physical simulation based the use of mathematical methods and aimed at the quantitative evaluation of the contribution of each factor to the indicated processes.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.