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Special Welding Techniques : Final Summary Report

Description: From foreword: This is the final report on Special Welding Techniques. The work of the third and final year is discussed in detail, and the accomplishments of the first two years are summarized.
Date: January 1957
Creator: Mueller, John; Maxwell, William & Siltanen, James
Partner: UNT Libraries Government Documents Department

Experimental data concerning the effect of high heat-input rates on the pressure drop through radiator tubes

Description: From Summary: "The pressure drops through electrically heated Inconel tubes with length-diameter ratios of 29.25, 58.50, 87.75, and 117.00 have been measured at entrance Mach numbers from approximately 0.12 to the value at which choking occurred. The heat-input rate was varied from zero to the highest values allowable without damaging the tubes. Experimental data and a number of computed variables are presented in tabular form."
Date: September 22, 1948
Creator: Habel, Louis W. & Gallagher, James J.
Partner: UNT Libraries Government Documents Department

Effect of Forging Temperature and Heat Treatment on the Performance of Inconel 700 Buckets at 1625 Degrees F in a J33-9 Turbojet Engine

Description: Report presenting an investigation to determine the effects of forging temperatures and solution treatments on the engine performance of Inconel 700 buckets. The buckets were tested in a J33-9 turbojet engine at 1625 degrees F in 20-minute cycles. Testing demonstrated that the buckets are capable of operating for more than 450 hours at rated speed.
Date: February 18, 1958
Creator: Gyorgak, C. A.; Springsteen, D. F. & Johnson, J. R.
Partner: UNT Libraries Government Documents Department

Performance of Inconel 739 Buckets in J33-9 Turbojet Engine

Description: Investigation of the performance of Inconel 739 (a nickel-base alloy of low critical-element content) buckets in a J33-9 engine showed that Inconel 739 had an engine life at least equivalent if not superior to S-816 buckets operated at 1500 degrees F. Inconel 739 buckets had a small scatter in life and exhibited lower total elongation than S-816. Bucket life was less than that predicted on; the basis of stress-rupture considerations alone. The failure mechanism was probably influenced by fatigue.
Date: October 8, 1956
Creator: Gyorgak, C. A. & Johnston, J. R.
Partner: UNT Libraries Government Documents Department

Fundamental aging effects influencing high-temperature properties of solution-treated Inconel X

Description: Report presenting studies of the effects of various aging treatments on the mechanical properties of solution-treated Inconcel X at 1200 degrees and 1500 degrees Fahrenheit for a variety of rupture times. Specimens were aged at 1200 degrees, 1400 degrees, and 1600 degrees Fahrenheit for time periods up to 1000 hours. Results regarding structural changes as a result of aging, mechanical behavior at the designated temperatures, and a comparison with work on low-carbon N-155 are provided.
Date: June 1951
Creator: Frey, D. N.; Freeman, J. W. & White, A. E.
Partner: UNT Libraries Government Documents Department

Tensile properties of Inconel X sheet under rapid-heating and constant-temperature conditions

Description: From Summary: "Results of rapid-heating tests of Inconel X sheet are presented for nominal temperature rates of 0.2 degrees F to 100 degrees F per second under constant tensile load conditions. Yield and rupture stresses obtained under rapid-heating conditions are compared with the results of conventional tensile stress-train tests at elevated temperatures. A marked increase in strength is observed with increased temperature rates."
Date: August 1957
Creator: Kurg, Ivo M.
Partner: UNT Libraries Government Documents Department

Tensile properties of Inconel and RS-120 titanium-alloy sheet under rapid-heating and constant-temperature conditions

Description: From Summary: "Results are presented of rapid-heating tests to determine the tensile strength of Inconel and RS-120 titanium-alloy sheet heated to failure at uniform temperature rates from 0.2 degrees Fahrenheit to 100 degrees Fahrenheit per second under constant load conditions. Yield and rupture stresses, obtained by rapid heating, are compared with yield and ultimate stresses from elevated-temperature tensile stress-strain tests for 1/2-hour exposure. The applicability of master curves and temperature-rate parameters to the prediction of yield and rupture stresses and temperatures under rapid-heating conditions was investigated."
Date: July 1956
Creator: Heimerl, George J.; Kurg, Ivo M. & Inge, John E.
Partner: UNT Libraries Government Documents Department

Forced-convection heat-transfer characteristics of molten Flinak flowing in an Inconel X system

Description: Memorandum presenting an experimental investigation of the forced-convection heat-transfer characteristics of Flinak flowing through an electrically heated Inconel X test section. The variables included Reynolds numbers, velocities, fluid temperatures, surface temperatures, and heat flux densities.
Date: February 1954
Creator: Grele, Milton D. & Gedeon, Louis
Partner: UNT Libraries Government Documents Department

Office of Naval Research and NACA Metallurgical Investigation of a Large Forged Disc of Inconel X Alloy

Description: Note presenting a study of the properties of a large forged disc of Inconel X alloy at room temperature, 1200, 1350, and 1500 degrees Fahrenheit in order to determine the level of properties obtainable in a forging of this type required for the rotor discs of gas turbines. Results regarding the hardness survey, short-term tensile properties, Charpy impact resistance, rupture test characteristics, time-deformation characteristics, creep strengths, stability characteristics, and comparison of properties of Inconel X with single and double aging treatments are provided.
Date: April 1949
Creator: Cross, Howard C. & Freeman, J. W.
Partner: UNT Libraries Government Documents Department

Performance of Inconel 550 Turbine Blades in a Turbojet Engine and Effects of Different Forging Temperatures and Heat Treatments

Description: Report presenting an investigation to determine the effects of forging at 1950 degrees and 2150 degrees Fahrenheit as well as the effects of several heat treatments on the performance of Inconel 550 in a turbojet engine. Differences in engine performance of the different turbine blades could not be associated with consistent differences in microstructure or grain size. Results regarding blade performance, blade elongation during engine operation, microstructure of as-heat-treated blades, grain size, metallurgical studies of failed blades, stress-rupture tests, and hardness are provided.
Date: August 16, 1955
Creator: Gyorgak, C. A.; Johnston, J. R. & Weeton, J. W.
Partner: UNT Libraries Government Documents Department

A new metallographic procedure for edge retention of enclosed surfaces

Description: Utilization of a low melting point, metallic alloy that on solidification has provided a reproducible means of preserving edges and accurately measuring deposits on surfaces mounted for metarographic study. In normal laboratory practice the electrically conducting mounting material generates no hazardous waste, needs no special equipment to prepare and is available commercially at a relatively reasonable price. Previous standard edge preservation techniques were found to be 90% inefficient from a time utilization view compared with the new procedure. This new mounting procedure has greatly improved the quality and efficiency of microstructural studies of all materials, especially those on the inside diameters of heat exchanger components. These studies have included reaction products, shallow creep cracks and deposits on tubing, for which the procedure has proved indispensable.
Date: August 1, 1994
Creator: Katz, O. M.
Partner: UNT Libraries Government Documents Department

Stress corrosion cracking behavior of Alloy 600 in high temperature water

Description: SCC susceptibility of Alloy 600 in deaerated water at 360 C (statically loaded U-bend specimens) is dependent on microstructure and whether the material was cold-worked and annealed (CWA) or hot-worked and annealed (HWA). All cracking was intergranular, and materials lacking grain boundary carbides were most susceptible to SCC initiation. CWA tubing materials are more susceptible to SCC initiation than HWA ring-rolled forging materials with similar microstructures (optical metallography). In CWA tubing materials, one crack dominated and grew to a visible size. HWA materials with a low hot-working finishing temperature (<925 C) and final anneals at 1010-1065 C developed both large cracks (similar to those in CWA materials) and small intergranular microcracks detectable only by destructive metallography. HWA materials with a high hot-working finishing temperature (>980 C) and a high-temperature final anneal (>1040 C), with grain boundaries that are fully decorated, developed only microcracks in all specimens. These materials did not develop large, visually detectable cracks, even after more than 300 weeks exposure. A low-temperature thermal treatment (610 C for 7h), which reduces or eliminates SCC in Alloy 600, did not eliminate microcrack formation in high temperature processed HWA materials. Conventional metallographic and analytical electron microscopy (AEM) were done on selected materials to identify the factors responsible for the observed differences in cracking behavior. Major difference between high-temperature HWA and low-temperature HWA and CWA materials was that the high temperature processing and final annealing produced predominantly ``semi-continuous`` dendritic M{sub 7}C{sub 3} carbides along grain boundaries with a minimal amount of intragranular carbides. Lower temperature processing produced intragranular M7C3 carbides, with less intergranular carbides.
Date: July 1, 1995
Creator: Webb, G.L. & Burke, M.G.
Partner: UNT Libraries Government Documents Department

A Tracer Study of the Transport of Chromium in Fluoride Fuel Systems

Description: The following report follows an experimental study that was made on the mass transport of chromium in polythermal inconel-fluoride fuel systems, followed by the technique of adding radioactive chromium-51 to the system as either CrF3 in the salt or as elemental chromium in the solid phase.
Date: June 18, 1957
Creator: Price, Robert B.; Sunderman, Duane Neuman; Pobereskin, Meyer & Calkins, George D.
Partner: UNT Libraries Government Documents Department

Radiochemical Analyses for Fe, Cr, Ni, and Co Corrosion Products

Description: Abstract: Radiochemical and carrier techniques have been applied to the determination of minute amounts of Fe, Cr, Ni, and Co which appear as corrosion products of Inconel. The results are as follows: Fe, 0.061 per cent; Cr, 0.15 per cent; Ni, 0.037 per cent; and Co, .0005 per cent.
Date: September 9, 1955
Creator: Smith, R. R.; Passell, T. O. & Reeder, S. D.
Partner: UNT Libraries Government Documents Department

Fracture behavior of nickel-based alloys in water

Description: The cracking resistance of Alloy 600, Alloy 690 and their welds, EN82H and EN52, was characterized by conducting J{sub IC} tests in air and hydrogenated water. All test materials displayed excellent toughness in air and high temperature water, but Alloy 690 and the two welds were severely embrittled in low temperature water. In 54 C water with 150 cc H{sub 2}/kg H{sub 2}O, J{sub IC} values were typically 70% to 95% lower than their air counterparts. The toughness degradation was associated with a fracture mechanism transition from microvoid coalescence to intergranular fracture. Comparison of the cracking response in water with that for hydrogen-precharged specimens tested in air demonstrated that susceptibility to low temperature cracking is due to hydrogen embrittlement of grain boundaries. The effects of water temperature, hydrogen content and loading rate on low temperature crack propagation were studied. In addition, testing of specimens containing natural weld defects and as-machined notches was performed to determine if low temperature cracking can initiate at these features. Unlike the other materials, Alloy 600 is not susceptible to low temperature cracking as the toughness in 54 C water remained high and a microvoid coalescence mechanism was operative in both air and water.
Date: August 1, 1999
Creator: Mills, W.J. & Brown, C.M.
Partner: UNT Libraries Government Documents Department

Irradiation-assisted stress corrosion cracking of HTH Alloy X-750 and Alloy 625

Description: In-reactor testing of bolt-loaded compact tension specimens was performed in 360 C water. New data confirms previous results that high irradiation levels reduce SCC resistance in Alloy X-750. Low boron heats show improved IASCC (irradiation-assisted stress corrosion cracking). Alloy 625 is resistant to IASCC. Microstructural, microchemical, and deformation studies were carried out. Irradiation of X-750 caused significant strengthening and ductility loss associated with formation of cavities and dislocation loops. High irradiation did not cause segregation in X-750. Irradiation of 625 resulted in formation of small dislocation loops and a fine body-centered-orthorhombic phase. The strengthening due to loops and precipitates was apparently offset in 625 by partial dissolution of {gamma} precipitates. Transmutation of boron to helium at grain boundaries, coupled with matrix strengthening, is believed to be responsible for IASCC in X-750, and the absence of these two effects results in superior IASCC resistance in 625.
Date: July 1, 1995
Creator: Bajaj, R.; Mills, W.J.; Lebo, M.R.; Hyatt, B.Z. & Burke, M.G.
Partner: UNT Libraries Government Documents Department

Irradiation assisted stress corrosion cracking of HTH Alloy X-750 and Alloy 625

Description: In-reactor testing of bolt-loaded precracked compact tension specimens was performed in 360{degree}C water to determine effect of irradiation on the SCC behavior of HTH Alloy X-750 and direct aged Alloy 625. Out-of-flux and autoclave control specimens provided baseline data. Primary test variables were stress intensity factor, fluence, chemistry, processing history, prestrain. Results for the first series of experiments were presented at a previous conference. Data from two more recent experiments are compared with previous results; they confirm that high irradiation levels significantly reduce SCC resistance in HTH Alloy X-750. Heat-to-heat differences in IASCC were related to differences in boron content, with low boron heats showing improved SCC resistance. The in-reactor SCC performance of Alloy 625 was superior to that for Alloy X-750, as no cracking was observed in any Alloy 625 specimens even though they were tested at very high K{sub 1} and fluence levels. A preliminary SCC usage model developed for Alloy X-750 indicates that in-reactor creep processes, which relax stresses but also increase crack tip strain rates, and radiolysis effects accelerate SCC. Hence, in-reactor SCC damage under high flux conditions may be more severe than that associated with postirradiation tests. In addition, preliminary mechanism studies were performed to determine the cause of IASCC In Alloy X-750.
Date: June 1, 1994
Creator: Mills, W. J.; Lebo, M. R.; Bajaj, R.; Kearns, J. J.; Hoffman, R. C. & Korinko, J. J.
Partner: UNT Libraries Government Documents Department


Description: Metal corrosion tests were conducted with four high waste loading non-Fe-limited HLW glass compositions. The results at 1150 C (the WTP nominal melter operating temperature) show corrosion performance for all four glasses that is comparable to that of other typical borosilicate waste glasses, including HLW glass compositions that have been developed for iron-limited WTP streams. Of the four glasses tested, the Bi-limited composition shows the greatest extent of corrosion, which may be related to its higher phosphorus content. Tests at higher suggest that a moderate elevation of the melter operating temperature (up to 1200 C) should not result in any significant increase in Inconel corrosion. However, corrosion rates did increase significantly at yet higher temperatures (1230 C). Very little difference was observed with and without the presence of an electric current density of 6 A/inch{sup 2}, which is the typical upper design limit for Inconel electrodes. The data show a roughly linear relationship between the thickness of the oxide scale on the coupon and the Cr-depletion depth, which is consistent with the chromium depletion providing the material source for scale growth. Analysis of the time dependence of the Cr depletion profiles measured at 1200 C suggests that diffusion of Cr in the Ni-based Inconel alloy controls the depletion depth of Cr inside the alloy. The diffusion coefficient derived from the experimental data agrees within one order of magnitude with the published diffusion coefficient data for Cr in Ni matrices; the difference is likely due to the contribution from faster grain boundary diffusion in the tested Inconel alloy. A simple diffusion model based on these data predicts that Inconel 690 alloy will suffer Cr depletion damage to a depth of about 1 cm over a five year service life at 1200 C in these glasses.
Date: November 5, 2009
Partner: UNT Libraries Government Documents Department

Fatigue acceptance test limit criterion for larger diameter rolled thread fasteners

Description: This document describes a fatigue lifetime acceptance test criterion by which studs having rolled threads, larger than 1.0 inches in diameter, can be assured to meet minimum quality attributes associated with a controlled rolling process. This criterion is derived from a stress dependent, room temperature air fatigue database for test studs having a 0.625 inch diameter threads of Alloys X-750 HTH and direct aged 625. Anticipated fatigue lives of larger threads are based on thread root elastic stress concentration factors which increase with increasing thread diameters. Over the thread size range of interest, a 30% increase in notch stress is equivalent to a factor of five (5X) reduction in fatigue life. The resulting diameter dependent fatigue acceptance criterion is normalized to the aerospace rolled thread acceptance standards for a 1.0 inch diameter, 0.125 inch pitch, Unified National thread with a controlled Root radius (UNR). Testing was conducted at a stress of 50% of the minimum specified material ultimate strength, 80 Ksi, and at a stress ratio (R) of 0.10. Limited test data for fastener diameters of 1.00 to 2.25 inches are compared to the acceptance criterion. Sensitivity of fatigue life of threads to test nut geometry variables was also shown to be dependent on notch stress conditions. Bearing surface concavity of the compression nuts and thread flank contact mismatch conditions can significantly affect the fastener fatigue life. Without improved controls these conditions could potentially provide misleading acceptance data. Alternate test nut geometry features are described and implemented in the rolled thread stud specification, MIL-DTL-24789(SH), to mitigate the potential effects on fatigue acceptance data.
Date: May 1, 1997
Creator: Kephart, A.R.
Partner: UNT Libraries Government Documents Department

Compatibility of gas turbine materials with steam cooling

Description: Objective is to investigate performance of gas turbine materials in steam environment and evaluate remedial measures for alleviating the severity of the problem. Three superalloys commonly used in gas turbines were exposed to 3 steam environments containing different impurity levels for 2 to 6 months. Results: Cr2O3-forming alloys containing 1-4% Al such as IN 738 are susceptible to heavy internal oxidation of Al. High Al (>5%) alloys in which continuous Al2O3 scale can be formed, may not be susceptible to such attack. Deposition of salts from steam will accentuate hot corrosion problems. Alloys with higher Cr content such as X-45 are generally less prone to hot corrosion. The greater damage observed in IN 617 make this alloy less attractive for gas turbines with steam cooling. Electrochemical impedance spectroscopy is a good nondestructive method to evaluate microstructural damage.
Date: December 31, 1995
Creator: Desai, V.; Tamboli, D. & Patel, Y.
Partner: UNT Libraries Government Documents Department