Abstract
1. The duration of the period of crack nucleation in steels N18K9M5T and 30KhN2MFA varies little with the magnitude of cyclic stresses. 2. A period of slow crack growth is observed in steels 30KhN2MFA and N18K9M5T at σmax=165 kgf/mm2 and is characterized by fatigue microbands in the fracture-ductile in the maraging steel, brittle in the medium-carbon steel. With increasing crack length (period of accelerated crack growth) the area occupied by microbands in the fracture decreases and the percentage of dimpled fracture increases. 3. At high cyclic stresses (σmax=260 and 360 kgf/mm2) the period of slow crack growth is absent in steels 30KhN2MFA and N18K9M5T. 4. The rate of crack growth determined by the difference of electrical potentials is in satisfactory agreement with the width of fatigue microbands, particularly in the period of slow crack growth. In the period of accelerated crack growth it is somewhat higher than the width of microbands. 5. The high regularity of fatigue microbands in the fractures of steel N18K9M5T indicates greater evenness of the properties determining the resistance to fracture at high cyclic impact loads than for steel 30KhN·2MFA.
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 callDisclaimer: 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.
