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in subjects: "Corrosion Resistant Alloys"

Bilinear Cyclic Stress-Strain Analysis for Incoloy 800

This report describes the bilinear stress-strain analysis under cyclic loading conditions for the alloy Incoloy 800. Although the method for determining the bilinear stress-strain parameters is based on a procedure proposed in the RDT Standard F9-1 for inelastic analysis of Fast Flux Test Facility (FFTF) components, the accuracy and consistency of results have been improved by an analytical technique, which also resulted in certain simplifications. The bilinear stress-strain parameters of solution-annealed Incoloy 800 (Heat HH7058A) under cyclic loading conditions at a strain rate of 8.6 x 10⁻⁵ s⁻¹, total strain range of 0.2 to 0.8 percent, and temperatures of room temperature to 593 degrees C (1100 degrees F) have been determined. The dependence of bilinear parameters on temperature and strain is discussed. The cyclic-hardening characteristics based on correlation of yield parameter k with accumulated plastic strain are also presented.

Date: 1977?

Creator: Maiya, P. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Basic Research Needs for Materials Under Extreme Environments. Report of the Basic Energy Sciences Workshop on Materials Under Extreme Environments, June 11-13, 2007

To evaluate the potential for developing revolutionary new materials that will meet demanding future energy requirements that expose materials to environmental extremes.

Date: February 1, 2008

Creator: Wadsworth, J.; Crabtree, G. W.; Hemley, R. J.; Falcone, R.; Robertson, I.; Stringer, J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Molten Salt Heat Transport Loop: Materials Corrosion and Heat Transfer Phenomena

An experimental system for corrosion testing of candidate materials in molten FLiNaK salt at 850 degree C has been designed and constructed. While molten FLiNaK salt was the focus of this study, the system can be utilized for evaluation of materials in other molten salts that may be of interest in the future. Using this system, the corrosion performance of a number of code-certified alloys of interest to NGNP as well as the efficacy of Ni-electroplating have been investigated. The mechanisums underlying corrosion processes have been elucidated using scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy of the materials after the corrosion tests, as well as by the post-corrosion analysis of the salts using inductively coupled plasma (ICP) and neutron activation analysis (NAA) techniques.

Date: July 9, 2008

Creator: Sridharan, Dr. Kumar; Anderson, Dr. Mark; Corradini, Dr. Michael; Allen, Dr. Todd; Olson, Luke; Ambrosek, James et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Effect of Alloy Composition, Free Volume and Glass Formability on the Corrosion Behavior of Bulk Metallic Glasses

Bulk metallic glasses (BMGs) have received significant research interest due to their completely amorphous structure which results in unique structural and functional properties. Absence of grain boundaries and secondary phases in BMGs results in high corrosion resistance in many different environments. Understanding and tailoring the corrosion behavior can be significant for various structural applications in bulk form as well as coatings. In this study, the corrosion behavior of several Zr-based and Fe-Co based BMGs was evaluated to understand the effect of chemistry as well as quenched in free volume on corrosion behavior and mechanisms. Presence of Nb in Zr-based alloys was found to significantly improve corrosion resistance due to the formation of a stable passive oxide. Relaxed glasses showed lower rates compared to the as-cast alloys. This was attributed to lowering of chemical potential from the reduced fraction of free volume. Potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) techniques helped in quantifying the corrosion rate and polarization resistance. The effect of alloy composition was quantified by extensive surface analysis using Raman spectroscopy, energy dispersive x-ray spectroscopy and auger spectroscopy. Pitting intensity was higher in the as-cast glasses than the relaxed glasses. The electrochemical behavior of a Zr-Ti-Cu-Ni-Be bulk metallic glass subjected to high strain processing was studied. High strain processing caused shear band formation and an increase in the free volume. Potentiodynamic polarization and EIS showed a strong correlation between the enthalpy of structural relaxation and corrosion rate and polarization resistance. Pitting was observed to preferentially occur on shear bands in the processed samples, while it was stochastic in unprocessed glass. The corrosion analysis of Co-Fe glasses showed an increase in corrosion current density when Fe content was increased from 0 to 7 at%. The corrosion resistance improved when Fe content was further increased to 15 at%. Similar trend was ...

Date: December 2015

Creator: Ayyagari, Venkata Aditya

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Corrosion performance of structural alloys in coal-combustion environments.

No abstract prepared.

Date: May 31, 2000

Creator: Natesan, K.; Mathur, M. & Freeman, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

Fabrication of Test Tubes for Coal Ash Corrosion Testing

This paper deals with the fabrication of tube sections of four alloys for incorporating into test sections to be assembled by Babcock & Wilcox (B&W) for installation at Ohio Edison Power, Niles Plant. The primary purpose of the installation was to determine the corrosion behavior of ten different alloys for flue gas corrosion. Ohio Edison Power, Niles Plant is burning an Ohio coal containing approximately 3.4% S (dry basis) and approximately 0.4% alkali which causes chronic coal ash corrosion of the unit�s superheater tubing. The 2.5-in.-OD x 0.4in.-wall x 6-in-long sections of four alloys {type 304H coated with Fe<sub>3</sub>Al alloy FAS [developed at the Oak Ridge National Laboratory (ORNL)], 310 + Ta, modified 800H, and Thermie alloy} were fabricated at ORNL. Each alloy tubing was characterized in terms of chemical analysis and microstructure. The machined tubes of each of the alloys were inspected and shipped on time for incorporation into the test loop fabricated at B&W. Among the alloys fabricated, Thermie was the hardest to extrude and machine.

Date: May 11, 1999

Creator: Johnson, R.; Judkins, R.R.; Sikka, V.K.; Swindeman, R.W. & Wright, I.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

Environmental Cracking of Corrosion Resistant Alloys in the Chemical Process Industry - A Review

A large variety of corrosion resistant alloys are used regularly in the chemical process industry (CPI). The most common family of alloys include the iron (Fe)-based stainless steels, nickel (Ni) alloys and titanium (Ti) alloys. There also other corrosion resistant alloys but their family of alloys is not as large as for the three groups mentioned above. All ranges of corrosive environments can be found in the CPI, from caustic solutions to hot acidic environments, from highly reducing to highly oxidizing. Stainless steels are ubiquitous since numerous types of stainless steels exist, each type tailored for specific applications. In general, stainless steels suffer stress corrosion cracking (SCC) in hot chloride environments while high Ni alloys are practically immune to this type of attack. High nickel alloys are also resistant to caustic cracking. Ti alloys find application in highly oxidizing solutions. Solutions containing fluoride ions, especially acid, seem to be aggressive to almost all corrosion resistant alloys.

Date: December 4, 2006

Creator: Rebak, R B

Item Type: Article

Partner: UNT Libraries Government Documents Department

Modeling the Effects of Crevice Former, Partculates, and the Evolving Surface Profile in Crevice Corrsion

Crevice corrosion is an important mode of localized corrosion to be evaluated for the long-term performance of corrosion resistant alloys in high temperature, aqueous environments. This work focuses on the evolution of corrosion damage of Ni-Cr-Mo alloys in hot brines. For the initiation of crevice corrosion, a critical crevice chemistry must develop within the crevice to break down the passive film. The geometry of the crevice and particularly the height of the crevice gap is an important parameter, with tighter crevices being more aggressive. Crevice corrosion models mostly define a smooth walled crevice of uniform gap and do not account for the changing profile after crevice corrosion has initiated. As a complement to the earlier models of the cathodic region, they focus here on the crevice (anodic) region and apply current and potential distribution models to examine the effects of the perturbed surface topography. The analysis focuses on three related issues: (1) the effects surface roughness of the metal and the crevice former, (2) the effects of particulate within the crevice, and (3) the evolution of the crevice profile in the active, anodic region.

Date: June 9, 2006

Creator: Landau, U.; Agarwal, A.S.; Shan, X. & Payer, J.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Electrochemical Deposition of Zinc-Nickel Alloys in Alkaline Solution for Increased Corrosion Resistance.

The optimal conditions for deposition of zinc-nickel alloys onto stainless steel discs in alkaline solutions have been examined. In the past cadmium has been used because it shows good corrosion protection, but other methods are being examined due to the high toxicity and environmental threats posed by its use. Zinc has been found to provide good corrosion resistance, but the corrosion resistance is greatly increased when alloyed with nickel. The concentration of nickel in the deposit has long been a debated issue, but for basic solutions a nickel concentration of 8-15% appears optimal. However, deposition of zinc-nickel alloys from acidic solutions has average nickel concentrations of 12-15%. Alkaline conditions give a more uniform deposition layer, or better metal distribution, thereby a better corrosion resistance. Although TEA (triethanolamine) is most commonly used to complex the metals in solution, in this work I examined TEA along with other complexing agents. Although alkaline solutions have been examined, most research has been done in pH ≥ 12 solutions. However, there has been some work performed in the pH 9.3-9.5 range. This work examines different ligands in a pH 9.3-9.4 range. Direct potential plating and pulse potential plating methods are examined for optimal platings. The deposits were examined and characterized by XRD.

Date: December 2009

Creator: Conrad, Heidi A.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Requirements for a cleanable steel HEPA filter derived from a systems analysis

A systems analysis was conducted to determine customer requirements for a cleanable high efficiency particulate air (HEPA) filter in DOE Environmental Management (EM) facilities. The three principal drivers for cleanable steel HEPA are large cost savings, improved filter reliability, and new regulations; they produce a strong incentive to DOE customers to use cleanable steel HEPA filters. Input for customer requirements were obtained from field trips to EM sites and from discussions. Most existing applications require that cleanable steel HEPA filters meet size/performance requirements of standard glass HEPA filters; applications in new facilities can relax size/weight/pressure drop requirements on a case-by-case basis. We then obtained input from commercial firms on availability of cleanable steel HEPA filters. Systems analysis then showed that currently available technology was only able to meet customer needs in a limited number of cases. Further development is needed to meet requirements of EM customers. For cleanable steel HEPA to be retrofitted into existing systems, pressure drop and weight must be reduced. Pressure drop can be reduced by developing steel fiber media from 0.5 {mu}m dia steel fibers. Weight can be reduced by packaging the steel fiber media in one of the standard HEPA configurations. Although most applications will be able to use standard 304 or 316L alloys, an acid resistant alloy such as Hastelloy or Inconel will be needed for incinerator and other thermal processes.

Date: June 1, 1996

Creator: Bergman, W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Effect of chloride concentration and pH on pitting corrosion of waste package container materials

Electrochemical cyclic potentiodynamic polarization experiments were performed on several candidate waste package container materials to evaluate their susceptibility to pitting corrosion at 90 degrees C in aqueous environments relevant to the potential underground high-level nuclear waste repository. Results indicate that of all the materials tested, Alloy C-22 and Ti Grade-12 exhibited the maximum corrosion resistance, showing no pitting or observable corrosion in any environment tested. Efforts were also made to study the effect of chloride ion concentration and pH on the measured corrosion potential (Ecorr), critical pitting and protection potential values.

Date: December 1, 1996

Creator: Roy, A.K.; Fleming, D.L. & Gordon, S.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

Laser Surface Alloying of Refractory Metals on Aluminum for Enhanced Corrosion Resistance: Experimental and Computational Approaches

Aluminum (Al) and its alloys are widely used in various technological applications, mainly due to the excellent thermal conductivity, non-magnetic, ecofriendly, easy formability and good recyclability. However due to the inferior corrosion resistance its applications are hampered in various engineering sectors. Besides, the corrosion related failures such as leakage of gas from pipeline, catastrophic breakdown of bridges and fire accidents in processing plants further puts the human life in jeopardy. Within the United States over $ 400 billion dollars per year are spent over research to understand and prevent the corrosion related failures. Recently, the development of transition metal(TM) aluminides (AlxTMy, where, TM = Mo, W, Ta, Nb, Cr, Zr and V) has received the global attention mainly due to high strength at elevated temperatures, light-weight, excellent corrosion and wear resistance. In light of this, surface modification via laser surface alloying (LSA) is a promising engineering approach to mitigate the corrosion and wear problems. In the present study the attempts are made to study the Al-Mo, Al-W, Al-Nb, and Al-Ta systems as a potential corrosion resistant coatings on aluminum. The refractory metal (Mo, W, Nb, Ta) precursor deposit was spray coated separately on aluminum substrate and was subsequently surface alloyed using a continuous wave diode-pumped ytterbium laser at varying laser energy densities. Microstructural analysis was conducted using scanning electron microscopy and further X-ray diffractometry was carried out to evaluate the various phases evolved during laser surface alloying. Corrosion resistance of laser alloyed coatings were evaluated using open circuit potential, cyclic potentiodynamic polarization, electrochemical impedance spectroscopy measurements were performed in 0.6 M NaCl solution (pH:6.9±0.2, 23˚C). Open circuit potential measurements indicate the more stable (steady state) potential values over long periods after laser surface alloying. Cyclic polarization results indicated reduction in the corrosion current density, enhancement in the polarization resistance, and ...

Date: December 2014

Creator: Rajamure, Ravi Shanker

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment : 1000-h Laboratory Test A

A laboratory test program is described to evaluate the corrosion behavior of several metallic alloys, coatings, claddings, and weldments in support of the atmospheric fluidized-bed air heater experiment. Results are presented from the first 1000-h test (Test A) conducted at metal and gas temperatures of 871 C and 899 C, respectively. Detailed information is also presented on the corrosion scale morphologies, scale compositions and thicknesses, intergranular penetration of the substrate material, and metal recession.

Date: March 1987

Creator: Natesan, K. & Podolski, W. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Materials Performance in the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment

The Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) sponsored by the US Department of Energy (DOE) was initiated to assess the performance of various heat-exchanger materials to be used in fluidized-bed combustion air heater systems. Westinghouse Electric Corporation, through subcontracts with Babcock Wilcox, Foster Wheeler, and ABB Combustion Engineering Systems, prepared specifications and hardware for the ACAHE tests. Argonne National Laboratory contracted with Rockwell International to conduct tests in the DOE atmospheric fluidized-bed combustion facility. This report presents an overview of the project, a description of the facility and the test hardware, the test operating conditions, a summary of the operation, and the results of analyzing specimens from several uncooled and cooled probes exposed in the facility. Extensive microstructural analyses of the base alloys, claddings, coatings, and weldments were performed on specimens exposed in several probes for different lengths of time. Alloy penetration data were determined for several of the materials as a function of specimen orientation and the exposure location in the combustor. Finally, the data were compared with earlier laboratory test data, and the long-term performance of candidate materials for air-heater applications was assessed.

Date: February 1991

Creator: Natesan, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Corrosion and Mechanical Behavior of Materials for Coal Gasification Applications

A state-of-the-art review is presented on the corrosion and mechanical behavior of materials at elevated temperatures in coal-gasification environments. The gas atmosphere in coal-conversion processes are, in general, complex mixtures which contain sulfur-bearing components (hydrogen sulfide, SO2, and COS) as well as oxidants (carbon dioxide/carbon monoxide and water/hydrogen). The information developed over the last five years clearly shows sulfidation to be the major mode of material degradation in these environments. The corrosion behavior of structural materials in complex gas environments is examined to evaluate the interrelationships between gas chemistry, alloy chemistry, temperature, and pressure. Thermodynamic aspects of high-temperature corrosion processes that pertain to coal conversion are discussed, and kinetic data are used to compare the behavior of different commercial materials of interest. The influence of complex gas environments on the mechanical properties such as tensile, stress-rupture, and impact on selected alloys is presented. The data have been analyzed, wherever possible, to examine the role of environment on the property variation. The results from ongoing programs on char effects on corrosion and on alloy protection via coatings, cladding, and weld overlay are presented. Areas of additional research with particular emphasis on the development of a better understanding of corrosion processes in complex environments and on alloy design for improved corrosion resistance are discussed.

Date: May 1980

Creator: Natesan, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Failure Analysis of Cracked Head Spray Piping from the Dresden Unit 2 Boiling Water Reactor

Several sections of Type 304 stainless steel head spray piping, 6.25 cm (2.5 in.) in diameter, from the Dresden Unit 2 Boiling Water Reactor were examined to determine the nature and causes of coolant leakages detected during hydrostatic tests. Extensive pitting was observed on the outside surface of the piping, and three cracks, all located at a helical stripe apparently rubbed onto the outer surface of the piping, were also noted. Metallographic examination revealed that the cracking had initiated at the outer surface of the pipe, and showed it to be transgranular and highly branched, characteristic of chloride stress corrosion cracking. The surface pitting also appeared to have been caused by chlorides. A scanning electron microprobe x-ray analysis of the corrosion product in the cracks confirmed the presence of chlorides and also indicated the presence of calcium.

Date: July 1983

Creator: Diercks, D. R. & Dragel, Gabriel M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Environmentally Assisted Cracking of Nickel Alloys - A Review

Nickel can dissolve a large amount of alloying elements while still maintaining its austenitic structure. That is, nickel based alloys can be tailored for specific applications. The family of nickel alloys is large, from high temperature alloys (HTA) to corrosion resistant alloys (CRA). In general, CRA are less susceptible to environmentally assisted cracking (EAC) than stainless steels. The environments where nickel alloys suffer EAC are limited and generally avoidable by design. These environments include wet hydrofluoric acid and hot concentrated alkalis. Not all nickel alloys are equally susceptible to cracking in these environments. For example, commercially pure nickel is less susceptible to EAC in hot concentrated alkalis than nickel alloyed with chromium (Cr) and molybdenum (Mo). The susceptibility of nickel alloys to EAC is discussed by family of alloys.

Date: July 12, 2004

Creator: Rebak, R

Item Type: Article

Partner: UNT Libraries Government Documents Department

Evaluation of the Cryofit tube joining system in selected plutonium chemical processing solutions

The Ni-Ti alloy Cryofit joining system has been evaluated for corrosion resistance to selected solutions encountered in the chemical processing of plutonium. Results indicated the Cryofit system has useful resistance to Al(NO/ sub 3/)/sub 3/, H/sub 2/C/sub 2/O/sub 4/, KOH, and very dilute H/sub 2/SO/sub 4/. The Cryofit system is not suitable for HNO/sub 3/ serv ice or for NH/sub 4/SCN service when used with 304 stainless steel. The Cryofit tube fitting system provides a means of connecting tubes and pipes without flanges, welds, or elevated temperatures. Permanent connections are made by removing a Cryofit coupling from liquid nitrogen and inserting the tubes to be joined into the ends of the coupling. As the coupling warms from liquid nitrogen to room temperature, it shrinks onto the tubing with tremendous force generated by intertnal stresses. (auth)

Date: December 27, 1973

Creator: Macki, J.M.; Terada, K. & Kochen, R.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Effect of thermomechanical processing on mechanical properties of Fe-16 at. % Al alloy

An iron-aluminum alloy containing 16 at. % Al, which is essentially free from environmental effect on its ductility, has been developed. This alloy has over 20% elongation at room temperature. This paper presents in detail the effect of vacuum versus air melting on the properties of Fe-16 at. % Al alloy. The comparative results have shown air-induction melting to produce lower room-temperature ductility for the identical processing steps. Additional processing steps required to improve the ductility of air-melted material are also identified.

Date: December 31, 1994

Creator: Sikka, V.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Microbiologically influenced corrosion. Final report for fiscal year 1995

Microbiologically influenced corrosion (MIC) is a serious concern when considering measures to guard against long-term corrosion of waste package containers at Yucca Mountain. An experimental program has been initiated to gain a better fundamental understanding of MIC in repository environments. Some engineering objectives will be achieved during the investigation: a reproducible apparatus and procedure for electrochemical monitoring of MIC will be developed; the most aggressive combinations of bacteria will be determined, and the MIC resistance of various candidate alloys for the multipurpose container (MPC) will be measured.

Date: June 6, 1996

Creator: Jones, D.A. & Amy, P.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Modeling the corrosion of high-level waste containers: CAM-CRM interface

A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological respository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as A516 or Monel 400. At the present time, Alloy C-22 and A516 are favored. This publication addresses the development of models to account for corrosion of Alloy C-22 surfaces exposed directly to the Near Field Environmental (NFE), as well as to the exacerbated conditions in the CAM-CRM crevice.

Date: June 1, 1998

Creator: Farmer, J.C.; Bedrossian, P.J. & McCright, R.D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Advanced Industrial Materials (AIM) Program: Compilation of project summaries and significant accomplishments, FY 1997

The mission of the Advanced Industrial Materials (AIM) Program is to support development and commercialization of new or improved materials to improve energy efficiency, productivity, product quality, and reduced waste in the major process industries. A fundamentally new way of working with industries--the Industries of the Future (IOF) strategy--concentrates on the major process industries that consume about 90% of the energy and generate about 90% of the waste in the industrial sector. These are the aluminum, chemical, forest products, glass, metalcasting, and steel industries. OIT has encouraged and assisted these industries in developing visions of what they will be like 20 or 30 years into the future, defining the drivers, technology needs, and barriers to realization of their visions. These visions provide a framework for development of technology roadmaps and implementation plans. The AIM Program supports IOF by conducting research and development on materials to solve problems identified in the roadmaps. This is done by National Laboratory/industry/university teams with the facilities and expertise needed to develop new and improved materials. Each project in the AIM Program has active industrial participation and support. Assessments of materials needs and opportunities in the process industries are an on-going effort within the program. These assessments are being used for program planning and priority setting, followed by support of work to satisfy those needs. All the industries have identified materials as critical, particularly for high-temperature strength, corrosion resistance, and wear resistance. Also important from the energy efficiency viewpoint are membranes, catalytic membranes, and reactors for separations, both for processing and waste reduction. AIM focuses, therefore, on high-temperature materials, corrosion resistant materials, wear resistant materials, strong polymers, coatings, and membrane materials for industrial applications.

Date: May 1, 1998

Item Type: Report

Partner: UNT Libraries Government Documents Department

Composite tube cracking in kraft recovery boilers: A state-of-the-art review

Beginning in the mid-1960s, increasing energy costs in Finland and Sweden made energy recovery more critical to the cost-effective operation of a kraft pulp mill. Boiler designers responded to this need by raising the steam operating pressure, but almost immediately the wall tubes in these new boilers began to corrode rapidly. Test panels installed in the walls of the most severely corroding boiler identified austenitic stainless steel as sufficiently resistant to the new corrosive conditions, and discussions with Sandvik AB, a Swedish tube manufacturer, led to the suggestion that coextruded tubes be used for water wall service in kraft recovery boilers. Replacement of carbon steel by coextruded tubes has solved most of the corrosion problems experienced by carbon steel wall tubes, however, these tubes have not been problem-free. Beginning in early 1995, a multidisciplinary research program funded by the US Department of Energy was established to investigate the cause of cracking in coextruded tubes and to develop improved materials for use in water walls and floors of kraft recovery boilers. One portion of that program, a state-of-the-art review of public- and private-domain documents related to coextruded tube cracking in kraft recovery boilers is reported here. Sources of information that were consulted for this review include the following: tube manufacturers, boiler manufacturers, public-domain literature, companies operating kraft recovery boilers, consultants and failure analysis laboratories, and failure analyses conducted specifically for this project. Much of the information contained in this report involves cracking problems experienced in recovery boiler floors and those aspects of spout and air-port-opening cracking not readily attributable to thermal fatigue. 61 refs.

Date: July 1, 1997

Creator: Singbeil, D.L.; Prescott, R.; Keiser, J.R. & Swindeman, R.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2 field testing

In Phase 1 of this project, a variety of developmental and commercial tubing alloys and claddings was exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347, RA85H, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, NF 709, 690 clad, and 671 clad for over 10,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, controlled to the operating metal temperatures of an existing and advanced-cycle, coal-fired boiler. Samples of each alloy are being exposed for 4,000, 12,000, and 16,000 hours of operation. The present results are for the metallurgical examination of the corrosion probe samples after approximately 4,400 hours of exposure.

Date: August 1996

Creator: Blough, J. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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