Compatibility Evaluation for Application of Lean Duplex Stainless Steels to Seawater Systems in Nuclear Power Plants

Abstract:

Lean duplex stainless steels have been developed in Korea for the purpose of being used in the seawater systems of industries. The flow velocity of some part of seawater systems in nuclear power plants is high and damages of components from corrosion are severe. Therefore, this environment requires using high strength and high corrosion resistant steels. The newly developed lean duplex stainless steels STS329LD(20.3Cr-2.2Ni-1.4Mo) and STS329J3L(22.4Cr-5.7Ni-3.6Mo) are evaluated for the compatibility in seawater systems of nuclear power plants. In this study, the physical & mechanical properties and corrosion resistance of two alloys were quantitatively evaluated in comparison with commercial stainless steel 316L. Microstructures and mechanical properties of them were analyzed and the electrochemical properties related to corrosion resistance were measured such as pitting potential, passive current density, and corrosion rates from Tafel analysis. Critical pitting temperatures were measured in accordance with ASTM G48E method. The pitting initiation time and lifetime for replacement were predicted from the PRE values of test alloys and empirical equations that have been formulated from the condenser tubes of a nuclear power plant.

• Periodical: Materials Science Forum (Volumes 654-656)
• Pages: 382-385
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.654-656.382
• Online since: June 2010
• Authors: Hyun Young Chang, Heung Bae Park, Young Sik Kim, Sang Kon Ahn, Kwang Tae Kim, Yoon Young Jang
• Keywords: CPT, Lean Duplex Stainless Steel, Life Prediction, Nuclear Power Plant (NPP)

References

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[3] ASTM G48-03, Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution, ASTM.

DOI: 10.1520/g0048-11r15

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[11] Y. S. Kim, Corrosion Science and Technology, 9, 20(2010) 0 10 20 30 40 50 STS316L STS329LD STS329J3L CPT, ( ℃℃℃℃ ) 0 5 10 15 20 25 30 35 PRE'30 CPT(℃℃℃℃) PRE'30 Fig. 4 CPT data of test alloys with overlapped scale of PREN30.