scholarly journals Micro-Galvanic Corrosion of Steam Generator Materials within Pores of Magnetite Flakes in Alkaline Solutions

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 899 ◽  
Author(s):  
Soon-Hyeok Jeon ◽  
Geun Song ◽  
Do Hur
Keyword(s):  
Steam Generator ◽  
Galvanic Corrosion ◽  
Area Ratio ◽  
Corrosion Products ◽  
Alkaline Solutions ◽  
Galvanic Coupling ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Alloy 690 ◽  
Water Reactors

In secondary coolant system of the pressurized water reactors, the reduced corrosion products such as metallic Cu and Pb particles were accumulated in the pores of the magnetite flakes and electrically contacted to the steam generator materials. The micro-galvanic corrosion behavior of steam generator materials (steam generator tube materials: Alloy 600 and Alloy 690, steam generator tube sheet materials: SA508 Gr.3) contacted to the corrosion products (magnetite, Cu, and Pb) was investigated in an alkaline solution. The steam generator materials considered in this study were all the anodic elements of the galvanic pair because their corrosion potentials were lower than those of the corrosion products. The corrosion rate of the steam generator materials was increased by the galvanic coupling with the each corrosion products, and was more accelerated with increasing the area ratio of the corrosion products to the steam generator materials. Among the corrosion products, Cu has the largest galvanic effect on steam generator materials in the pores when area ratio of cathode to anode is 10.

U.S. Operating Experience With Thermally Treated Alloy 600 Steam Generator Tubes

2002 ◽  
Author(s):  
April Smith ◽  
Kenneth J. Karwoski
Keyword(s):  
Steam Generator ◽  
Operating Experience ◽  
Alloy 600 ◽  
Steam Generators ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Water Reactors ◽  
1960S And 1970S ◽  
The 1960S ◽  
Thermally Treated

Steam generators placed in service in the 1960s and 1970s were primarily fabricated from mill-annealed Alloy 600. Over time, this material proved to be susceptible to stress corrosion cracking in the highly pure primary and secondary water chemistry environments of pressurized-water reactors. The corrosion ultimately led to the replacement of steam generators at numerous facilities, the first U.S. replacement occurring in 1980. Many of the steam generators placed into service in the 1980s used tubes fabricated from thermally treated Alloy 600. This tube material was thought to be less susceptible to corrosion. Because of the safety significance of steam generator tube integrity, this paper evaluates the operating experience of thermally treated Alloy 600 by looking at the extent to which it is used and recent results from steam generator tube examinations.

scholarly journals Zeta Potentials of Magnetite Particles and Alloy 690 Surfaces in Alkaline Solutions

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3999
Author(s):  
Ji-Min Lee ◽  
Dong-Seok Lim ◽  
Soon-Hyeok Jeon ◽  
Do Haeng Hur
Keyword(s):  
Magnetite Nanoparticles ◽  
Ph Value ◽  
Alkaline Solutions ◽  
Empirical Formulas ◽  
Pressurized Water ◽  
Zeta Potentials ◽  
Alloy 690 ◽  
Magnetite Particles ◽  
Water Reactors ◽  
And Performance

Magnetite particles deposited on the secondary side of a steam generator (SG) can degrade the integrity and performance of pressurized water reactors. Therefore, it is necessary to produce the data of fundamental interfacial electrokinetic properties of magnetite particles and SG tube materials. This study investigated the zeta potentials of magnetite nanoparticles and Alloy 690 surfaces, which were dependent on the pH value, pH agent, and the presence of NaCl. The zeta potentials of the magnetite nanoparticles increased in the negative direction as the pH increased, regardless of the pH agent. At the same pH value, the absolute values of the zeta potentials with different pH agents were: ethanolamine < ammonia < morpholine. In the presence of NaCl, the zeta potentials of the particles further increased negatively. The meaning of the measured zeta potentials was discussed in terms of the dispersion stability and the agglomeration of the particles. Based on the relationship between the zeta potentials of the particles and Alloy 690 surfaces, the magnetite deposition on Alloy 690 was also discussed. Furthermore, the empirical formulas for the pH-dependent zeta potentials of magnetite particles in each alkaline solution were suggested.

scholarly journals Effects of Advanced Amines on Magnetite Deposition of Steam Generator Tubes in Secondary System

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 514
Author(s):  
Yong-Beom Lee ◽  
Ji-Min Lee ◽  
Do-Haeng Hur ◽  
Jong-Hyeon Lee ◽  
Soon-Hyeok Jeon
Keyword(s):  
Steam Generator ◽  
Ph Value ◽  
Secondary System ◽  
Pressurized Water ◽  
Zeta Potentials ◽  
Alloy 690 ◽  
Environmental Treatment ◽  
Average Porosity ◽  
Magnetite Particles ◽  
Water Reactors

Ethanolamine (ETA) is widely used to control the pH value in the secondary water of pressurized water reactors. However, it is necessary to consider other advanced amines which can replace ETA due to its serious human hazards and environmental treatment problems. The purpose of this study is to contemplate the effects of three advanced amines (ETA, 3-methoxypropylamine (MPA), and dimethylamine (DMA)) on the magnetite deposition behavior of a thermally treated (TT) Alloy 690 tubes by using a steam generator (SG) tube fouling loop in simulated secondary water. All particles were identified as a magnetite and were polyhedral or spherical in shape. When using ETA, MPA, and DMA, the average porosity of the deposits was about 34.7%, 33.0%, and 24.6%, respectively. The amount of deposits was largest when ETA was added, and it decreased by 41% when adding MPA and 55% when adding DMA. The mechanism of magnetite deposition was discussed in terms of zeta potentials of both the magnetite particles and the Alloy 690TT surface and magnetite solubility depending on the amines. To compare the potential for replacing ETA with other advanced amines, the various factors such as SG integrity, human hazards, and environmental treatment problems were discussed.

PWR Steam Generator Tube and AVB Wear Under Perpendicular Impacting

2013 ◽  
Author(s):  
Christian Phalippou ◽  
Franck Ruffet ◽  
Emmanuel Herms ◽  
François Balestreri
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Published Data ◽  
Steam Generators ◽  
Dynamic Interactions ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Wear Rates ◽  
Alloy 690

Flow-induced vibrations of steam generator tubes in nuclear power plants may result in wear damage at support locations. The steam generators in EPR power plants have a design life of 60 years; as wear is an identified ageing damage in steam generators, it is therefore important to collect experimental results on wear of tube and support due to dynamic interactions at EPR secondary side temperature. In this study, wear tests were performed between a steam generator tube (Alloy 690) and two flat opposite anti-vibration bars (AVB in 410s stainless steel) at different impact force levels. Tests were performed in pressurized water at 290°C in wear machines for long term repeated predominant impact motions. The worn surfaces were observed by SEM, the wear coefficients of tube and AVB were evaluated using the work rate approach. Significant scoring, due to the importance of sliding when impacts occur, was shown on wear scar patterns. There were greater wear volumes and depths on tubes than on AVBs, but dynamic forced conditions and rigid mounting of AVB in the rigs have prevailed for finally getting an upper bound of the wear rates. Alloy 690 for tubes and 410s for AVB remain a satisfactory material combination considering comparative wear results with other published data.

INCONEL FILLER METAL 52

Alloy Digest ◽  
1992 ◽  
Vol 41 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Arc Welding ◽  
Filler Metal ◽  
Pressurized Water Reactors ◽  
Pressurized Water ◽  
High Chromium ◽  
Inconel Alloy ◽  
Gas Tungsten Arc ◽  
Alloy 690 ◽  
Water Reactors

Abstract INCONEL FILLER METAL 52 is a high chromium filler metal for gas-metal-arc and gas-tungsten-arc welding of Inconel Alloy 690 (See Alloy Digest Ni-266, March 1981). Higher chromium is beneficial in resisting stress-corrosion cracking in high purity water for pressurized water reactors and for resistance to oxidizing acids. This datasheet provides information on composition and tensile properties. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-412. Producer or source: Inco Alloys International Inc..

Evaluation of the Creep Rupture Behavior of Alloy 690 Steam Generator Tubes Considering the Pressure Ramp Rate

2021 ◽  
Author(s):  
Jongmin Kim ◽  
Min-Chul Kim ◽  
Joonyeop Kwon
Keyword(s):  
Steam Generator ◽  
Creep Rupture ◽  
Parameter Method ◽  
Alloy 600 ◽  
Steam Generator Tube ◽  
Failure Pressure ◽  
Alloy 690 ◽  
Rupture Model ◽  
Temperature And Pressure ◽  
Steam Generator Tubes

Abstract The materials used previously for steam generator tubes around the world have been replaced and will be replaced by Alloy 690 given its improved corrosion resistance relative to that of Alloy 600. However, studies of the high- temperature creep and creep-rupture characteristics of steam generator tubes made of Alloy 690 are insufficient compared to those focusing on Alloy 600. In this study, several creep tests were conducted using half tube shape specimens of the Alloy 690 material at temperatures ranging from 650 to 850C and stresses in the range of 30 to 350 MPa, with failure times to creep rupture ranging from 3 to 870 hours. Based on the creep test results, creep life predictions were then made using the well-known Larson Miller Parameter method. Steam generator tube rupture tests were also conducted under the conditions of a constant temperature and pressure ramp using steam generator tube specimens. The rupture test equipment was designed and manufactured to simulate the transient state (rapid temperature and pressure changes) in the event of a severe accident condition. After the rupture test, the damage to the steam generator tubes was predicted using a creep rupture model and a flow stress model. A modified creep rupture model for Alloy 690 steam generator tube material is proposed based on the experimental results. A correction factor of 1.7 in the modified creep rupture model was derived for the Alloy 690 material. The predicted failure pressure was in good agreement with the experimental failure pressure.

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