Abstract
The exploitation of geothermal energy as one of new energy sources has been highlighted, and now it is mainly utilized for generating electric power. However, it has become a problem that the fatigue strength of stainless steels used for the turbine blades and other parts decreases due to corrosion by H2S contained in geothermal steam. In order to solve this problem, the corrosion fatigue test on 13 Cr-Mo, 12 Cr-Mo-V, 3 Cr-Mo, Cr-Mo-V and 3.7 Ni-Cr-Mo steels was carried out in geothermal steam at the Onikobe Geothermal Power Station.The main results obtained are summarized as follows:(1) The fatigue strength of steels in geothermal steam was much lower than that in air. The rate of decrease in fatigue strength was smallest for 13 Cr-Mo steel, and was largest for 3.7 Ni-Cr-Mo steel among five steels.(2) 13 Cr-Mo steel was corroded very little even if being exposed in geothermal steam for a very long period.(3) A method of estimating fatigue strength at 109∼1012 number of cycles in geothermal steam from the corrosion fatigue strength of the specimen and the fatigue strength of the corroded specimen was established by separating the cycle-dependent effect of fatigue damage from the time dependent effect of corrosion damage. For this purpose the corrosion coefficient Kc=1+B·t0n1·Nfn2, where t0 and Nf are corrosion time and number of cycles was defined. For 13Cr-Mo steel, B=4.33×10-3, n1=0.11, n2=0.22 were obtained.
Sign-in/Register to access full text options 
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 callMore From: Journal of the Society of Materials Science, Japan
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.
