Intergranular stress corrosion cracking(IGSCC)is the dominant failure mechanism experience by stainless steel components in the high temperature aqueous environments of boiling water reactors.The susceptibilities of IGSCC can be linked to the electrochemical chemical potentials(ECP)of stainless steel in the BWR environments.To mitigate IGSCC,hydrogen water chemistry is implemented to encourage the recombination reaction of hydrogen with oxygen at the metal surface,making stainless steel in the ECP region less prone to cracking.However,the state of oxygen deficiency at the metal surface may be altered by increasing flow rate.Higher amount of dissolved oxygen even at low concentrations can be transported to the metal surface and ECP of stainless steels can be anodically increased as a result.On the other hand,stronger flushing action of increasing flow can dilute the aggressive crack tip environments,thereby reducing the IGSCC susceptibilities.Whether increasing flow will be beneficial or detrimental to IGSCC will depend on factors such as crack geometry,flow rate,oxygenation,and crack tip environments.Flow rate effect experiments are performed using compact tension and thumbnail specimens.Results indicate that increasing flow rate generally has a beneficial effect.When crack propagation rates below 1x10-7 mm/s,increasing flow rate will reduce crack growth due to better mixing of the crack tip environment.Between the range of 1x10-7 mm/s and1x10-6mm/s,crack growth remains generally unchanged at higher flow rate.However,when crack growth rate reaches above 1x10-6mm/s,high flow rate can exert an detrimental acceleration effect on crack growth.Fractographic features of the Compact Tension and Thumbnail specimens also demonstrate the inhibiting effect on IGSCC by arresting the crack at the surface edges where flow is strongest.