Effect of Heavy Ion Irradiation Dosage on the Hardness of SA508-IV Reactor Pressure Vessel Steel
- Resource Type
- article
- Authors
- Xue Bai; Sujun Wu; Peter K. Liaw; Lin Shao; Jonathan Gigax
- Source
- Metals, Vol 7, Iss 1, p 25 (2017)
- Subject
- SA508-IV
displacement per atom (dpa)
ion irradiation hardening
inflection point
reactor pressure vessel (RPV) steel
nano-hardness
Mining engineering. Metallurgy
TN1-997
- Language
- English
- ISSN
- 2075-4701
Specimens of the SA508-IV reactor pressure vessel (RPV) steel, containing 3.26 wt. % Ni and just 0.041 wt. % Cu, were irradiated at 290 °C to different displacement per atom (dpa) with 3.5 MeV Fe ions (Fe2+). Microstructure observation and nano-indentation hardness measurements were carried out. The Continuous Stiffness Measurement (CSM) of nano-indentation was used to obtain the indentation depth profile of nano-hardness. The curves showed a maximum nano-hardness and a plateau damage near the surface of the irradiated samples, attributed to different hardening mechanisms. The Nix-Gao model was employed to analyze the nano-indentation test results. It was found that the curves of nano-hardness versus the reciprocal of indentation depth are bilinear. The nano-hardness value corresponding to the inflection point of the bilinear curve may be used as a parameter to describe the ion irradiation effect. The obvious entanglement of the dislocations was observed in the 30 dpa sample. The maximum nano-hardness values show a good linear relationship with the square root of the dpa.