Stress Corrosion Cracking of NiCrMoV Steel Welded Joint under Applied Load in Simulated Environment of Low Pressure Nuclear Steam Turbine

Abstract:

In order to determine the stress corrosion cracking susceptibility of NiCrMoV steel welded joint of low pressure nuclear steam turbine, long time immersion tests had been carried out in the form of cylindrical tensile specimens self-loaded to various applied load (0, 0.3YS, 0.6YS and 0.9YS) and exposed in the simulated environment with 180°C, 3.5% NaCl. Coarsen grain heat affected zone reacted preferentially as anode in welded joint, which was caused by the synthetic effects of micro-galvanic corrosion, much more precipitations of carbides and higher content of Cr element. Preferential local corrosion of coarsen grain heat affected zone with the formation of occluded corrosion cell accelerated corrosion rate. In addition, the dissolution rate also increased as the applied load increased.

• Periodical: Applied Mechanics and Materials (Volume 853)
• Pages: 361-365
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.853.361
• Online since: September 2016
• Authors: Shuo Weng, Yu Hui Huang, Fu Zhen Xuan*, Ling Hua Luo
• Keywords: Applied Load, Long Time Immersion Test, Micro-Galvanic Corrosion, Occluded Corrosion Cell, Self-Loaded Cylindrical Tensile Specimens, Stress Corrosion Cracking

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