Abstract
A tailored-for-purpose environmental fatigue testing facility was previously developed to perform direct strain-controlled tests on stainless steel in simulated PWR water. Strain in specimen mid-section is generated by the use of pneumatic bellows, and eddy current measurement is used as a feedback signal. The procedure conforms with the ASTM E 606 practice for low cycle fatigue, giving results which are directly compatible with the major NPP design codes. Past studies were compiled in the NUREG/CR-6909 report and environmental reduction factors Fen were proposed to account for fatigue life reduction in hot water as compared to a reference value in air. This database exclusively contained nonstabilized stainless steels, mainly tested under stroke control. The applicability of the stainless steel Fen factor for stabilized alloys was already challenged in past papers (PVP2013-97500, PVP2014-28465). The results presented in this paper follow the same overall trend of lower experimental values (4.12-11.46) compared to those expected according to the NUREG report (9.49-10.37). In this paper results of a dual strain rate test programme on niobium stabilized AISI 347 type stainless steel are presented and discussed in the context of the NUREG/CR-6909 Fen methodology. Special attention is paid to the effect of strain signal on fatigue life, which according to current prediction methods does not affect the value of F en.
Original language | English |
---|---|
Title of host publication | ASME 2016 Pressure Vessels and Piping Conference |
Subtitle of host publication | Codes and Standards |
Publisher | American Society of Mechanical Engineers (ASME) |
Number of pages | 5 |
Volume | 1A |
ISBN (Print) | 978-0-7918-5035-0 |
DOIs | |
Publication status | Published - 2016 |
MoE publication type | A4 Article in a conference publication |
Event | ASME 2016 Pressure Vessels and Piping Conference - Vancouver, Canada Duration: 17 Jul 2016 → 21 Jul 2016 |
Conference
Conference | ASME 2016 Pressure Vessels and Piping Conference |
---|---|
Country/Territory | Canada |
City | Vancouver |
Period | 17/07/16 → 21/07/16 |
Keywords
- alloy steel
- eddy current testing
- fatigue of materials
- fatigue testing
- pressure vessels
- stainless steel
- steel testing
- environmental fatigue
- experimental values
- fatigue life reduction
- low cycle fatigue testing
- low cycle fatigues
- prediction methods
- strain rate tests
- strain-controlled