Characteristics of fatigue crack initiation and fatigue strength of nitrided 1Cr-1Mo-0.25V turbine rotor steels
- 1. Kyungpook National Univ., Taegu (Korea, Republic of)
- 2. Tokushima Univ., Tokushima (Japan)
Description
To investigate the effect of nitriding layer on both fatigue crack initiation and fatigue life, turbine rotor steel (1Cr-1Mo-0.25V steel) specimens were nitrided by the nitemper method and then put to a rotary bending fatigue test at room and elevated temperatures. In nitriding, temperature and time were controlled to obtain a different nitrided thickness. Microstructure analysis, micro-Vickers hardness test, and scanning electron microscope observation were carried out for evaluating experiments. In results, the fatigue cracks of nitrided specimens were initiated at inclusion near the interface between nitrided layer and substrate, which showed fish-eye appearance in fractography. The fatigue life of nitrided specimens at every temperature was prolonged compared to that of the non-nitrided. However, there was not observable improvement in fatigue characteristics with the increase of a nitrided thickness
Additional details
Publishing Information
- Journal Title
- KSME International Journal
- Journal Volume
- 16
- Journal Issue
- 8
- Series
- 15 refs, 10 figs, 2 tabs
- Journal Page Range
- p. 1109-1116
- ISSN
- 1226-4865
INIS
- Country of Publication
- Korea, Republic of
- Country of Input or Organization
- Korea, Republic of
- INIS RN
- 36106255
- Subject category
- S36: MATERIALS SCIENCE;
- Descriptors DEI
- CARBON; CRACKS; FATIGUE; HARDNESS; NITRIDES; RESIDUAL STRESSES; ROTORS; STEELS; TURBINES
- Descriptors DEC
- ALLOYS; CARBON ADDITIONS; ELEMENTS; EQUIPMENT; IRON ALLOYS; IRON BASE ALLOYS; MACHINERY; MECHANICAL PROPERTIES; NITROGEN COMPOUNDS; NONMETALS; PNICTIDES; STRESSES; TRANSITION ELEMENT ALLOYS; TURBOMACHINERY