Showing papers on "Inconel published in 1995"
TL;DR: In this paper, a single-point continuous turning test was carried out on a G-17 cast iron and a nickel base, Inconel 718, alloy using round and rhomboid-shape pure oxide (Al 2 O 3 + ZrO 2 ) and mixed oxide (al. 3 + TiC) tools to study the extent of damage on the machined surfaces.
117 citations
TL;DR: Friction and wear behavior of TiN, ZrN and CrN coatings in contact with Inconel (trademark of the International Nickel Co Inc) 718 were investigated using a ring-on-disc test machine at 500°C and 600°C as discussed by the authors.
Abstract: Friction and wear behavior of TiN, ZrN and CrN coatings in contact with Inconel (trademark of the International Nickel Co, Inc) 718 were investigated using a ring-on-disc test machine at 500°C and 600°C The applied load was 267 N and the linear velocity was 124 m s−1 The wear of the coatings was extremely small compared with that of Inconel 718, which was found to depend strongly on its mating coating At 500°C, the wear performance of ZrN- and CrN-Inconel 718 wear couples were comparable to or better than an uncoated couple, respectively At 600°C, the wear performance of CrN-Inconel 718 was markedly better than that of ZrN-Inconel 718 The microstructural and chemical characterization of wear surfaces and debris were investigated by scanning electron microscopy and energy dispersive spectrometry X-ray diffraction revealed that the wear debris from all wear couples consisted of NiCr2O4, NiO, Cr2O3 and Inconel 718 Based on the morphology and chemistry changes of wear surfaces and phase compositions of wear debris, the adhesive and oxidative wear was the primary mechanism for the uncoated Inconel 718 wear couple For the coating-Inconel 718 couples, the abrasive and oxidative wear accounted for material removal of the Inconel 718 disc; the adhesive wear and oxidative and chemical wear were responsible for the coating removal
117 citations
TL;DR: In this paper, the CBN grinding wheel is found to possess particularly good grinding properties and is most suitable for grinding Inconel 718 when compared with WA and GC grinding wheels, but it has high cost.
73 citations
28 Feb 1995-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, a titanium silicide Ti5Si3 was found to be beneficial to improvement of the creep resistance of a fully lamellar Ti-48Al-1.5Cr cast alloy without the sacrifice of tensile properties.
Abstract: Precipitation of a titanium silicide Ti5Si3 was found to be beneficial to improvement of the creep resistance of a fully lamellar Ti-48Al-1.5Cr cast alloy without the sacrifice of tensile properties. The addition of 0.26–0.65 mol% Si generates fine precipitates less than 200 nm in size during aging at 900 °C for 5 h. The precipitates are effective obstacles to dislocation motion and raise the stress exponents of power law creep significantly. The specific creep strength of Si-containing alloys is better than that of a conventional Ni-base cast superalloy Inconel 713C at 800 °C for 10 000 h.
67 citations
TL;DR: In this article, it was shown that the enrichment and segregation of niobium at grain boundary surfaces played an important role in the environmental enhancement of creep crack growth in the Inconel 718.
Abstract: These initial results strongly suggest that the enrichment and segregation of niobium at grain boundary surfaces played an important role in the environmental enhancement of creep crack growth in the Inconel 718. The precise mechanism, however, still needs to be established. Available evidence suggests that the mechanism involves the formation and fracture of a brittle niobium oxide film on the boundary surfaces which reduces the alloy's crack growth resistance. Oxidation and decomposition of NbC particles at the crack tip surfaces and at the grain boundaries appear to be the principal source of niobium. The segregated niobium (in the form of Ni3Nb precipitates) at the grain boundaries is expected to also contribute to the embrittlement. The source of oxygen would be that of an external (pseudo-equilibrium) surface oxide. The mechanism would be consistent with the observed independence on oxygen pressure from 2.67 to 100 kPa. The rate controlling process would be identified with the reactions of oxygen with niobium carbides (266 versus 287 kJ/mol) or with the segregated niobium. The lower activation energy for crack growth in moist argon and air (about 190 kJ/mol) still needs to be understood. It may reflect the additional embrittlement contribution from hydrogen, and a transfer of the rate controlling process. Further studies are underway to critically examine this and other hypotheses in developing a more complete understanding. The important role of niobium in the enhancement of creep crack growth in nickel-base superalloys is demonstrated by the correlation between environmental sensitivity and niobium concentration in a series of commercial alloys. The detailed aspects of the interactions with niobium are under investigation and will be reported later.
51 citations
TL;DR: In this paper, a study of tool deterioration in the end milling of Inconel 718 using uncoated tungsten carbide inserts under dry conditions is presented.
46 citations
TL;DR: Inconel 718 was also tested in the solution annealed condition and serrations were seen in the plastic portions of stress-strain hysteresis loops from the beginning until the end of the fatigue life.
Abstract: Serrated flow was observed in Inconel 718 during strain controlled fatigue at room temperature when tested after a double aging treatment. The material was also tested in the solution annealed condition. In both conditions, unlocking type serrations were seen in the plastic portions of stress-strain hysteresis loops, from the beginning until the end of the fatigue life. The back stress, exerted by accumulated parallel pile-ups of dislocations in planar slip bands and subsequent relaxation of internal stress by initiating new plastic flow in adjacent grains, is proposed to be the cause of serrated flow in this alloy at room temperature.
41 citations
TL;DR: In this paper, the corrosion behavior of five commercially available alloys (AISI 316L, AISI 310S, Inconel 601, Thermax 4762, and Kanthal A1) in molten carbonate under reducing gas atmospheres was investigated with cyclic voltammetry and quasi-stationary polarization curve measurements.
Abstract: The corrosion behavior of five commercially available alloys (AISI 316L, AISI 310S, Inconel 601, Thermax 4762, and Kanthal A1) in molten carbonate under reducing gas atmospheres was investigated with cyclic voltammetry and quasi-stationary polarization curve measurements. The reactions that proceed on these materials at distinct potentials could be deduced by comparison of the cyclic voltammograms and polarization curves with those of pure metals and model alloys. The shape of the polarization curves of all materials strongly depends on the preceding electrochemical treatment. A polarization curve recorded immediately after immersion of a sample resulted in a high anodic current. This implies that the passivation of the materials is poor. When a specimen was conditioned at {minus}1,060 mV for 10 h before recording the polarization curve, the anodic current diminished, which indicates passivation. This occurred for all materials except AISI 316L. A ranking of the corrosion properties was determined from polarization curves of samples that had been conditioned assuming the current densities to be representative. The resistance against corrosion of the alloys increases in the order: AISI 316L
40 citations
Patent•
27 Jul 1995
TL;DR: In this article, a method of heat treating articles cast of a superalloy, comprising a nickel-base alloy capable of forming a chromium carbide precipitate, such as INCONEL 939™, is described.
Abstract: A method of heat treating articles cast of a superalloy, comprising a nickel-base alloy capable of forming a chromium carbide precipitate, such as INCONEL 939™. The method includes selective heating of the article to cause chromium and carbon nuclei in the lattice of the crystals in the superalloy to go into solution, and selective cooling of the article to cause the formation of discrete chromium carbide nuclei along the grain boundary of the crystals. Additional heating steps may be performed to enhance the size of the chromium carbide nuclei. Articles so treated have improved mechanical properties.
34 citations
TL;DR: In this article, the wear mechanism of high speed steel drill failures was investigated and it was shown that attrition, abrasion, adhesion and plastic deformation could singly or jointly contribute to the wear of the drill when machining Inconel 901.
33 citations
TL;DR: In this article, the effect of aging on the interfacial microstructure and tensile properties of as-welded and postweld heat treated alloy 800/9Cr-1Mo steel joint was investigated.
TL;DR: In this paper, the authors showed that even trace concentrations of sulphide/sulphate under normal pH control are react with alloys whose oxide films appear permeable to nickel transport.
TL;DR: In this article, the performance of alloy 617 in actual and simulated gas turbine environments is presented and some mechanical property data are included to show the stability of the alloy after exposure to high temperatures for an extended period of time.
Abstract: INCONEL® alloy 617 is a solid solution, nickel-chromium-cobalt-molybdenum alloy with an exceptional combination of high-temperature strength, oxidation and carburization resistance and thermal stability. In this paper, the performance of alloy 617 in actual and simulated gas turbine environments will be presented. In addition some mechanical property data will be included to show the stability of the alloy after exposure to high temperatures for an extended period of time. For comparison the data obtained on such alloys as INCO® alloy HX, Haynes alloys HS188®, 214® and 230® are also reported. (INCONEL and INCO are trademarks of the Inco family of companies. HS188, 214 and 230 trademarks of Haynes International).
TL;DR: In this paper, a spray pyrolysis growth system has been employed for the formation of superconducting YBa 2 Cu 3 O x (YBCO) thick films on polycrystalline Ni/NiO, Inconel 600, and inconel X substrates ranging in thickness from 80-100 μm.
TL;DR: In this article, Mo was applied on two superalloys, Inconel 600 and Nimonic PE11, using air plasma spraying and was tested at 750°C for up to 168 h in an environment comprising p S2 ~ 10 −1 Pa and p O 2 ~ 10−18 Pa. The exposed samples were characterized and analyzed using SEM, EDX and XRD techniques.
Abstract: Sulphidation is a serious problem in many energy conversion systems. Sulphidation attack is particularly severe in environments of low oxygen ( p O2 ~10 −18 Pa) and high sulphur ( p S2 ~ 10 −1_10−3 Pa) potentials at temperatures above 700°C. Recognizing that refractory metals have a high resistance to sulphidation in reducing environments, their use as overlay coatings in sulphur-containing environments deserves serious consideration. In the adoption of such an approach, Mo has been recognized as a highly sulphidation-resistant metal with a Kp value of 10 −12 g 2 cm −4 s −1 in an atmosphere of p S2 ~ 10 −1 Pa at 750°C. In this study, Mo was deposited on two superalloys, Inconel 600 and Nimonic PE11, using air plasma spraying. The coated specimens were tested at 750°C for up to 168 h in an environment comprising p S2 ~ 10 −1 Pa and p O2 ~ 10 −18 Pa. The sulphidation kinetics (this is not real through-layer kinetics, since the specimens had open edges) were determined by a discontinuous gravimetric method. The exposed samples were characterized and analysed using SEM, EDX and XRD techniques. For uncoated Inconel 600, a duplex scale was formed which consisted of an outer Ni 3 S 2 layer and an inner Cr 2 S 3 layer. The scale developed on uncoated Nimonic PE11 comprised three sub-scale layers—an outer (Fe, Ni) 9 S 8 layer, a mid Cr 2 S 3 layer and an inner MoS 2 layer. However, after prolonged exposure, the outer layer contained both (Fe, Ni) 9 S 8 and Ni 3 S 2 on the surface of the uncoated Nimonic PE11. The kinetics results demonstrated that Mo coating enhanced the corrosion resistance of both alloys, and particularly so for Nimonic PE11. For both substrates, Mo coating led to the development of two sub-scale layers at the early stages of exposure (e.g. up to 5 h). The outer layer consisted of Ni 3 S 2 for Inconel 600 and (Fe, Ni) 9 S 8 for Nimonic PE11. A MoS 2 layer constituted the inner layer for both materials. After prolonged sulphidation, a Cr 2 S 3 layer gradually developed between the outer layer and the inner MoS 2 layer. It is apparent that the use of Mo coating hindered the formation of the Cr 2 S 3 layer.
TL;DR: In this paper, a PACVD-coated Inconel 600 with a gaseous mixture of TiCl4, N2, H2 and Ar was used to evaluate the pitting resistance and mechanism in 100°C NaCl solution.
TL;DR: In this paper, it was shown that the underpotential deposition of zinc on AISI 4340 steel and Inconel 718 alloys inhibits the hydrogen evolution reaction and the degree of hydrogen ingress.
Abstract: It is shown that the underpotential deposition of zinc on AISI 4340 steel and Inconel 718 alloys inhibits the hydrogen evolution reaction and the degree of hydrogen ingress. In the presence of monolayer coverage of zinc on the substrate surfaces, the hydrogen evolution current densities are reduced 46% and 68% compared with the values obtained on bare AISI 4340 steel and Inconel 718 alloy, respectively. As a consequence, the underpotential deposition of zinc on AISI 4340 steel and Inconel 718 alloy membrane reduces the steady state hydrogen permeation current density by 51% and 40%, respectively.
TL;DR: In this paper, a special test rig was designed that measured the dependence of corrosion rate on both current density and temperature over extended periods of time, and the corrosion rates showed strong dependencies on the current density.
Abstract: Vitrification by joule-heating requires suitable electrode materials. Molybdenum electrodes are used often in high temperature (∼1500°C) joule-heated melters producing commercial glass while Inconel 690 has been the material of choice for lower temperature (∼1150°C) high-level nuclear waste vitrification. Vitrification of diverse waste streams at higher-temperatures places increasingly severe demands upon the electrode materials. Some commercially available ceramics possess sufficient conductivity at high temperatures to be used as electrodes. Many mixed- and low-level waste vitrification applications involve significant amounts of reducible species that accelerate the corrosion process for metallic electrodes. In addition, the corrosion rate of all electrode materials depends on the electrode current density. A special test rig was designed that measures the dependence of corrosion rate on both current density and temperature over extended periods of time. Molybdenum, Inconel 690, and three types of commercial ceramic coupons were tested over a range of conditions in simulated waste glasses containing key reducible species (e.g., PbO, CuO, ZnO, SO3). The corrosion rates show strong dependencies on the current density. Coupons were sectioned and the glass-coupon interface examined using Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS). Cu, Pb, Ni and Sn were found to be reduced to their metallic states at the molybdenum coupon surfaces and were active in the corrosion process.
Abstract: Superalloy 718, which is strengthened by {gamma}{prime} and {gamma}{double_prime} precipitates, is one of the most widely used nickel based superalloys for high temperature applications. The alloy also contains incoherent delta phase and MC type of carbides, and in rare cases the Laves phase and minor phases like borides. The performance of this alloy depends on the relative amount of all these phases. Due to its prominent overall mechanical properties up to 7650 C and fairly good formability, the alloy has found extensive usage in gas turbine disc applications. In these applications, the notch stress rupture performance is extremely important. In service, high temperature components are often subjected to a complex stress system which may vary from a uniaxial to a multi-axial stress state. Circumferentially notched round bars have been used to investigate the creep rupture behavior of other superalloys. The experimental results obtained in Inconel X-750 and Nimonic 80A have shown that the creep damage mechanisms were strongly influenced by the state of stress imposed by the notch. Several studies on superalloy 718 at high temperature showed variations in notch rupture life, depending on the size, morphology and distribution of delta phase. This paper reports the investigation carried out tomore » determine the factors responsible for inconsistent notch rupture behavior in superalloy 718.« less
Patent•
29 Aug 1995
TL;DR: In this article, the authors proposed a method to prevent the elution of a radioactive corrosive substance formed by the irradiation with neutron into primary cooling water by forming the oxide film of a specified element on the surface of a precipitation-hardened Ni-base alloy for an atomic fuel aggregate.
Abstract: PURPOSE:To prevent the elution of a radioactive corrosive substance formed by the irradiation with neutron into primary cooling water by forming the oxide film of a specified element on the surface of a precipitation-hardened Ni-base alloy for an atomic fuel aggregate. CONSTITUTION:A spring to be used for the spacer ring, leak control plate, etc., of a BWR fuel aggregate is produced from 'Inconel -750 (R)' or 'Inconel 718 (R)' as a precipitation-hardened Ni-base alloy and oxidized, for example, at 704 deg.C for 20hr in the atmosphere to form an oxide film having >=10 atomic % TiO2, based on the total oxide film atom, on the surface and an oxide film having >=10 atomic % Cr2O3, based on the total oxide film atom, inside. The elution of the radioactive corrosion product formed in 'Inconel (R)' by the irradiation with neutron into cooling water is significantly suppressed by the double oxide film, and the radiation dose is decreased in the working environment.
01 Oct 1995-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the effect of thermal cycles and the time at peak temperature and stress on the elastic strains developed during pressure loading of the joints was examined and the results suggest that creep damage caused during the hold period at high temperature can influence the loading-unloading strains, which generally increases with increasing damage.
Abstract: Dissimilar joints between ferritic and ausenitic materials are complex in terms of the heterogeneity of the weldment structures and their physical, mechanical and time dependent properties. Recent work studied the effect of slow thermal cycles, incorporating pressure increases and hold periods at the peak temperature, on the strain accumulated in dissimilar welds between 2.25CrIMo low alloy steel and Type 316 stainless steel fabricated with Inconel and Type 316 filler metals. The current paper examines the effect of thermal cycles and the time at peak temperature and stress on the elastic strains developed during pressure loading of the joints. The results suggest that creep damage caused during the hold period at high temperature can influence the loading-unloading strains, which generally increases with increasing damage. It is suggested that such methods could have potential for monitoring of creep damage in dissimilar welds in service and laboratory test situations.
Patent•
23 Jan 1995
TL;DR: In this article, an inconel material was electroplated with Ag at 5 to 50A/100cm 2 high current density by using a plating soln contg 012 to 12g/l silver cyanide and 80 to 100 g/l potassium cyanide.
Abstract: PURPOSE: To improve the adhesion of a metallic plating film on the surface of an inconel material by etching the surface with a mixed soln of hydrochloric acid and sulfuric acid and forming ruggedness CONSTITUTION: At the time of plating an inconel (R) material with Ag, Cu, Ni, Cr, Zn, Sn or the like, previously, the plating face of the inconel material is subjected to etching treatment with a mixed soln of HCl-H 2 SO 4 composed of, by weight, 4 to 30% HCl concn and 5 to 40% H 2 SO 4 concn to form a fine rugged face on the surface Successively, this rugged face is applied with Ag striking at 5 to 50A/100cm 2 high current density by using a plating soln contg 012 to 12g/l silver cyanide and 80 to 100g/l potassium cyanide, which is thereafter electroplated with Ag at 01 to 10A/100cm 2 current density by using a plating soln contg 30 to 90g/l silver cyanide, 80 to 100g/l potassium cyanide and 5 to 100g/l potassium carbonate The Ag plated inconel member excellent in the adhesion of the inconel to Ag plating film can be obtd COPYRIGHT: (C)1996,JPO
Patent•
04 Apr 1995
TL;DR: In this paper, the 21/4 Cr-1 Mo steel contg. Nb and V and austenitic stainless steel are welded with inconel or stainless steel base welding material.
Abstract: PURPOSE:To prevent thermal stress cracking in a weld zone between 21/4 Cr-1 Mo steel and austenitic stainless steel. CONSTITUTION:The 21/4 Cr-1 Mo steel 13 contg. Nb and V added with <=0.1wt.% Nb and 0.25-0.35wt.% V is held between the 21/4 Cr-1 Mo steel 11 and the austenitic stainless steel 12 and the 21/4 Cr-1 Mo steel 11 and 217/4 Cr-1 Mo steel 13 contg. Nb and V are welded with a 21/4 Cr-1 Mo steel welding material. The 21/4 Cr-1 Mo steel contg. Nb and V and austenitic stainless steel are welded with inconel or stainless steel base welding material.
TL;DR: In this article, a model based on a parabolic growth law is developed for ranking the severity of processing conditions for a pure Al matrix reinforced by continuous fibres of Inconel 601.
Abstract: The processing parameters for achieving proper control of the kinetics of interface reaction even in very reactive systems are discussed. The work concentrates on composites consisting of a pure Al matrix reinforced by continuous fibres of Inconel 601. Use is made of a low thermal inertia squeeze casting set-up equipped with monitoring of the sample temperature. Microstructural characterization and DTA analysis allow to elucidate some aspects of the reaction mechanisms. A model based on a parabolic growth law is developed for ranking the severity of processing conditions.
Patent•
15 Aug 1995
TL;DR: In this paper, a welding structure capable of easily welding without generating welding faults such as welding cracking or defective fusion was proposed to provide an easy way to provide a welding framework without causing welding faults.
Abstract: PURPOSE:To provide a welding structure capable of easily welding without generating welding faults such as welding cracking or defective fusion. CONSTITUTION:A ferrite steel tube 3 is welded onto an end of an austenite steel tube 2, the ferrite steel tube 3 is inserted at first onto a groove part of a ferrite tube plate 1 at first, between the ferrite steel tube 3 and the ferrite steel tube plate 1 is welded with ferrite base metal 5, and between the austenite steel tube 2 and the ferrite steel tube plate 1 is welded with Inconel base metal 6.
Patent•
13 Jan 1995
TL;DR: In this paper, an Fe-Ni base alloy with a compsn. contg., by weight, = two kinds among 0.0005 to 0.01% B, 0.00% Ca and 0.02% Mg may be added thereto.
Abstract: PURPOSE:To obtain an Fe-Ni base alloy having excellent cold workability so as to facilitate working even to an extremely thin sheet, an extremely thin strip and an extra fine wire and furthermore excellent in heat resistance. CONSTITUTION:This Fe-Ni base alloy is a one having a compsn. contg., by weight, = two kinds among 0.0005 to 0.01% B, 0.0005 to 0.02% Ca and 0.0005 to 0.02% Mg may be added thereto. It shows extremely excellent cold workability as well as heat resistance equal to or above that of 'Inconel 751 R ' and 'Inconel X750 R '.