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Steam generation tubing materials have the susceptibility of stress corrosion cracking(SCC)under the severe steam conditions.Alloy 600,Alloy 800 and Alloy 690 are widely used as the steam generation tubing materials in the past in different type of reactors.Due to the obvious difference of Cr content in these alloys,the difference of resistant to SCC of Alloy 600,Alloy 800 and Alloy 690 is apparently.Simultaneously,SCC susceptibility can be influenced by metallurgical condition,heat treatment and operating parameters of the tubes.This presentation introduces the experimental results of the stress corrosion cracking susceptibility of Alloy 600MA,Alloy 600TT,Alloy 600HTMA,Alloy 800 and Alloy 690TT in the solutions of 10%NaOH and 10%NaOH+Pb at high temperature by means of SCC tests of reverse-U bend specimens.Though the Slow Strain Rate Test(SSRT),we investigated the effect of strain rate,dissolved oxygen and Zn on the stress corrosion cracking of alloy 600 at high temperature.The strain rate,dissolved oxygen concentration,and Zn concentration significantly influences the SCC susceptibility of Alloy 600 at high temperature.The high strain rate is more resistant to SCC than the low strain rate for Alloy 600.The SCC susceptibility of Alloy 600 decreased remarkably in the solution of air+water environment compared with the deaerated water environment.With the Zn addition to the deaerated water,the resistant to SCC of Alloy 600 was considerably improved.This can be attributed to the changes of the oxide structure.