Study of stress corrosion cracking of alloy 600 in high temperature high pressure water

Student thesis: Phd


Stress corrosion cracking (SCC) of alloy 600 is regarded as one of the most importantchallenges to nuclear power plant operation worldwide.This study investigates two heats of alloy 600 (forged control rod drive mechanismnozzle and rolled divider plate) in order to obtain a better understanding ofthe effects of the material parameter on the SCC phenomenon. The experimentalapproach was designed to determine the effect of the manufacturing process (forgedvs. rolled), the cold-work (as-received vs. cold-worked) and the strain path(monotonic vs. complex) on SCC of alloy 600.Specimens with different strain paths have been produced from two materials representativeof plant components and tested in high temperature (360 C) highpressure primary water environment. The manufacturing process has been provento have a great effect on the stress corrosion cracking behaviour of alloy 600.Indeed, the SCC susceptibility assessment has demonstrated that the rolled materialis resistant to SCC even after cold work, whereas the forged material is susceptiblein the as-received state.Microstructural characterisations have been undertaken to explain these differencesin SCC behaviour. The carbide distribution is the main microstructuralparameter influencing SCC but the misorientation, in synergy with the carbidedistribution, has been proven to give a better representation of the materials SCCsusceptibilities.
Date of Award31 Dec 2010
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorRobert Cottis (Supervisor)


  • SCC
  • Strain path
  • Misorientation
  • Stress corrosion cracking
  • Alloy 600

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