Oxidation Products in Inconel Alloys 600 and 690 Under Hydrogenated Steam Environments and Their Role in Stress Corrosion Cracking

2010 ◽  
Vol 1276 ◽  
Author(s):  
Hugo F. Lopez
Keyword(s):  
Crack Initiation ◽  
Oxidation Products ◽  
Alloy 600 ◽  
Initiation Mechanism ◽  
Water Steam ◽  
Inconel Alloy ◽  
Inconel Alloys ◽  
Alloy 690 ◽  
Gel Film ◽  
The Stability

AbstractThermodynamic considerations for the stability of Ni and Cr compounds developed under PWR environments (PH2O and PH2) are experimentally tested. In particular, the experimental outcome indicates that Ni(OH)2 and CrOOH are thermodynamically stable products under actual PWR conditions (T < 360°C and Pressures of up to 20 MPa). Accordingly, a mechanism is proposed to explain crack initiation and growth in inconel alloy 600 along the gbs. The mechanism is based on the existing thermodynamic potential for the transformation of a protective NiO surface layer into an amorphous non-protective Ni(OH)2 gel. This gel is also expected to form along the gbs by exposing the gb Ni-rich regions to H2 supersaturated water steam. Crack initiation is then favored by tensile stressing of the gb regions which can easily rupture the brittle gel film. Repeating the sequence of reactions as fresh Ni is exposed to the environment is expected to also account for crack growth in Inconel alloy 600. The proposed crack initiation mechanism is not expected to occur in alloy 690 where a protective Cr2O3 film covers the metal surface. Yet, if a pre-existing crack is present in alloy 690, crack propagation would occur in the same manner as in alloy 600.

Electrochemical Interpretation of a Stress Corrosion Cracking of Thermally Treated Ni Base Alloys in a Lead Contaminated Water

2007 ◽  
Vol 124-126 ◽  
pp. 1545-1548 ◽  
Author(s):  
Seong Sik Hwang ◽  
Yun Soo Lim ◽  
Hong Pyo Kim ◽  
Joung Soo Kim ◽  
Larry Thomas
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Lead Ion ◽  
Contaminated Water ◽  
Alloy 600 ◽  
Electrochemical Test ◽  
Alloy 690 ◽  
Corrosion Film ◽  
The Stability

Since the PbSCC(Lead stress corrosion cracking) of alloy 600 tubing materials was reported by Copson and Dean in 1965, the effect of lead on a corrosion film and cracking morphology have been continually debated. An electrochemical interaction of lead with the alloying elements of SG tubings was studied and the corrosion products were analyzed. It was found that lead enhanced the anodic dissolution of alloy 600 and alloy 690 in the electrochemical test. The lead preferentially dissolved the Cr from the corrosion film of alloy 600 and alloy 690 in alkaline water. The lead ion seemed to penetrate into the TG crack tip and react with the corrosion film. A selective Cr depletion was observed to weaken the stability of the passive film on the alloys. Whereas passivity of Ni became stable in lead containing solution, Cr and Fe passivity became unstable.

The Corrosion Resistance of Inconel Alloy 600 in High Temperature Phosphate Solutions

CORROSION ◽  
1977 ◽  
Vol 33 (4) ◽  
pp. 130-144 ◽  
Author(s):  
N. PESSALL ◽  
A. B. DUNLAP ◽  
D. W. FELDMAN
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Sodium Phosphate ◽  
Spectroscopic Studies ◽  
Alloy 600 ◽  
Inconel Alloy ◽  
Raman Spectroscopic ◽  
Alloy 800 ◽  
Alloy 690 ◽  
Phosphate Solutions

Abstract A test program is described in which the corrosion resistance of Inconel Alloy 600 and other alloys is evaluated in sodium phosphate solutions at temperatures between 275 and 325 C. For Inconel Alloy 600, a significant increase in corrosion resistance is associated with the increase in phosphate solubility which occurs when the Na/P ratio (r) is reduced from 3.0 to below 2.0. In solutions characterized by 2 &gt; r &gt; 1.35, the corrosion resistance of Inconel Alloy 600 exhibits a minimum value. Inconel Alloy 690 and Incoloy Alloy 800 exhibit similar corrosion behavior. Raman spectroscopic studies of sodium phosphate solutions indicate a conversion at 200 C of Na3PO4 → Na2HPO4, while both Na2HPO4 and NaH2PO4 are stable up to 320 C. The Raman spectra provide the basis for a good correlation between the corrosion resistance of Inconel Alloy 600 and the concentration of HPO4= or H2PO4− species in the high temperature phosphate environments.

scholarly journals STRESS CORROSION CRACK INITIATION OF COLD-WORKED ALLOY 600 AND ALLOY 690 IN PWR PRIMARY WATER

2014 ◽  
Author(s):  
Stephen Bruemmer ◽  
Matthew Olszta ◽  
Daniel Schreiber ◽  
Mychailo Toloczko
Keyword(s):  
Crack Initiation ◽  
Stress Corrosion ◽  
Stress Corrosion Crack ◽  
Alloy 600 ◽  
Alloy 690 ◽  
Primary Water ◽  
Cold Worked

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..

Comparative TG/DTG/DTA+FTIR Studies Concerning the Stability of Some Mineral and Vegetable Electro-Insulating Fluids

2018 ◽  
Vol 69 (9) ◽  
pp. 2366-2371
Author(s):  
Andrei Cucos ◽  
Petru Budrugeac ◽  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Andreea Voina
Keyword(s):  
Vegetable Oils ◽  
Electrical Equipment ◽  
Inert Atmosphere ◽  
Oxidation Products ◽  
Gaseous Products ◽  
Mineral Oils ◽  
Ftir Studies ◽  
Dta Analysis ◽  
Anti Oxidant ◽  
The Stability

Thermal TG/DTG/DTA analysis coupled with FTIR spectroscopy was applied to some sorts of mineral and vegetable oils used in electrical equipment. On heating in inert atmosphere, it was observed that the mineral oils vaporize, while the vegetable oils undergo hydrolysis, yielding fatty acids as main volatiles, as indicated by FTIR. In synthetic air, the FTIR spectra of gaseous products confirm the presence of similar oxidation products, both for mineral and vegetable oils. The TG results indicated that the vegetable-based oils exhibit a substantially higher thermal stability than the mineral oils. The presence or absence of anti-oxidant inhibitors in these oils greatly influences the onset of the oxidation process in air environment factor, as results from the DTA results.

scholarly journals Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions

2019 ◽  
Vol 268 ◽  
pp. 06002 ◽  
Author(s):  
Kensuke Seno ◽  
Ilhwan Park ◽  
Carlito Tabelin ◽  
Kagehiro Magaribuchi ◽  
Mayumi Ito ◽  
...  
Keyword(s):  
Protective Coating ◽  
Sulfide Mineral ◽  
Sulfide Minerals ◽  
Low Ph ◽  
Oxidation Products ◽  
Arsenic Sulfide ◽  
Catecholate Complex ◽  
Coating Stability ◽  
The Stability

Arsenopyrite (FeAsS) is the most common primary arsenic-sulfide mineral in nature, and its oxidation causes the release of toxic arsenic (As). To mitigate these problems, carrier-microencapsulation (CME), a technique that passivates sulfide minerals by covering their surfaces with a protective coating, has been developed. In the previous study of authors on CME, Al-catecholate complex significantly suppressed arsenopyrite oxidation via electron donating effects of the complex and the formation of an Al-oxyhydroxide coating. For the application of this technique to real tailings, however, further study should be carried out to elucidate long-term effectiveness of the coating to suppress arsenopyrite oxidation. This study investigates the stability of the coating formed on arsenopyrite by Al-based CME using weathering tests. The Al-oxyhydroxide coating suppressed arsenopyrite oxidation until about 50 days of the experiment, but after this, the amounts of oxidation products like dissolved S and As increased due to the gradual dissolution of the coating with time as a result of the low pH of leachate. This suggests that co-disposal of Al-based CME-treated arsenopyrite with minerals that have appropriate neutralization potentials, so that the pH is maintained at around 5 to 8 where Al-oxyhydroxide is stable.

Relationship between ferromagnetic properties and grain size of Inconel alloy 600

2015 ◽  
Vol 381 ◽  
pp. 56-64 ◽  
Author(s):  
H. Kikuchi ◽  
H. Takahashi ◽  
H. Yanagiwara ◽  
T. Murakami
Keyword(s):  
Grain Size ◽  
Alloy 600 ◽  
Inconel Alloy ◽  
Ferromagnetic Properties

Very High Cycle Fatigue Behavior and Life Prediction of a Low Strength Weld Metal at Moderate Temperature

2011 ◽  
Author(s):  
Ming-Liang Zhu ◽  
Fu-Zhen Xuan ◽  
Zhengdong Wang
Keyword(s):  
Crack Initiation ◽  
Weld Metal ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Fatigue Properties ◽  
Dissimilar Welding ◽  
Initiation Mechanism ◽  
Metallic Inclusions ◽  
Low Strength ◽  
Very High

The fatigue properties of a low strength weld metal in a dissimilar welding joint in high cycle and very high cycle regimes were investigated by fully reversed axial tests in air at room temperature and 370°C. A clear duplex S-N curve existed as a result of the transition of fatigue failure mode from surface-induced failure to internal-induced failure at 370°C, while the S-N curve was continuously decreased at room temperature. A new model was successfully proposed to predict fatigue life, and interpret the crack initiation modes transition from surface inclusion to interior inclusion. It was concluded that cracks were initiated by competition among non-metallic inclusions, welding pores and discontinuous microstructures in high cycle regime. While in the very high cycle regime, non-metallic inclusions were the dominant crack initiation mechanism which depended on stress level, inclusion size as well as inclusion depth.

The Analysis of the Stress Field and Crack of Rock under the Blast Loading

2010 ◽  
Vol 168-170 ◽  
pp. 1252-1255
Author(s):  
Zhong Guo Zhang ◽  
Ya Dong Bian ◽  
Bin Gao
Keyword(s):  
Stress Field ◽  
Crack Initiation ◽  
Crack Extension ◽  
Crack Tip ◽  
Blast Loading ◽  
Crack Arrest ◽  
The Stability ◽  
Crack Tip Stress

The crack tip stress field of rock is analyzed under blast loading, and the crack arrest criterion, the conditions of rock crack initiation and crack extension are presented in this paper. The study will help the design of maintaining the stability of stope drift active workings.

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