High Strength Nickel Alloy Research Articles

Crystallographic Study of Grain Refinement in Ni Alloys with Ni-RE Intermetallics

Rare earth-doped nickel (Ni-RE) alloys are very attractive for the neutron shielding application for excellent neutron absorption and good mechanical behavior. Ni-RE intermetallics are important for their precipitation reinforcement in Ni alloys. In this work, Ni-RE intermetallics have been founded to be Ni grain refiners, which has been proved both by nucleation crystallography analysis and experiments. Ni-RE intermetallics could work as heterogeneous nucleation well, either different in atomic structures (for example, Ni17RE2, Ni5RE, Ni7RE2, Ni3RE, Ni2RE having matching orientation relationships as (111)Ni // (0004)Ni17Gd2 with , (111)Ni // (0002)Ni5Gd with , (111)Ni // (00018)Ni7Gd2 with , (111)Ni // (00012)Ni3Gd with , (111)Ni // (222)Ni2Gd with ) or different in rare earth element (for example, (111)Ni // (0002)Ni5RE with is general matching orientation relationships (ORs) of Ni5RE (RE = Sc, Y, La ~ Lu) for Ni grains). When RE dopant mass fraction is 1 wt%, the grain size is reduced from ~50 μm to 15 μm, and the refinement effect reaches the best. The work proposes Ni-RE intermetallics as good heterogeneous nuclei for Ni grains with an atomic level understanding and provides theoretical guidance for high-strength nickel alloy design.

Friction welding of high-strength casting nickel alloy VZh172L

Technological parameters of continuous drive friction welding of cast nickel superalloy VG172L have been chosen. The alloy was welded in the same name combination and also with the deformed variant of nickel superalloy VG172, mechanical properties and structural peculiarities of produced welded were studied.

Welding dissimilar high-strength nickel alloys in poly- and single-crystal combinations

The Paton Welding Journal, 2021, №06. International Scientific-Technical and Production Journal «The Paton Welding Journal» «The Paton Welding Journal» has been published monthly since 2000 in English, ISSN 0957-798X. «The Paton Welding Journal» is a cover-to-cover English translation of the «Avtomaticheskaya Svarka» (Automatic Welding) journal. The «Avtomaticheskaya Svarka» journal has been published monthly since 1948 in Russian, ISSN 005-111X.

Influence of Mo and Al elements on the vacuum high temperature tribological behavior of high strength nickel alloy matrix composites

Abstract Vacuum along with high temperature is typical service condition for machinery components operated in aerospace. In this paper, the effects of Al and Mo elements on the mechanical and vacuum tribological properties of the nickel-alloy matrix solid-lubricating composites were investigated. Results presented that the increased addition of Al element noticeably improved the wear resistance and mechanical properties of the composites due to the formation of intermetallic in composites. While increasing content of Mo element means higher Vickers hardness and lower wear rate at low and moderate temperatures. The wear mechanism was proposed based on microstructure and compositions of sliding surface.

SUMITOMO SMC276-125

Abstract Sumitomo SMC276-125 (minimum yield strength of 125 ksi, or 862 MPa) is a high-strength nickel alloy (nominal 16% Mo) for use in oil country tubular goods as a material suitable for severe sour service. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Ni-738. Producer or source: Nippon Steel and Sumitomo Metal Corporation.

SUMITOMO SM2050-125

Abstract Sumitomo SM2050-125 is a high-strength nickel alloy for use in oil country tubular goods as a material suitable for severe sour service. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Ni-736. Producer or source: Nippon Steel and Sumitomo Metal Corporation.

SUMITOMO SM2550-125

Abstract Sumitomo SM2550-125 is a high strength nickel alloy for use in oil country tubular goods as a material suitable for severe sour service. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Ni-735. Producer or source: Nippon Steel and Sumitomo Metal Corporation.

Modelling rotary friction welding of VZh175 high creep strength nickel alloy

The technological parameters of rotary friction welding of VZh175 nickel superalloy with high creep resistance and subjected to different heat treatment were investigated. The second-order polynomials are derived. The ranges of the optimum parameters of rotary friction welding are determined.

SUMITOMO SMC276-110

Abstract Sumitomo SMC276-110 (minimum yield strength of 110 ksi, or 758 MPa) is an austenitic high-strength nickel alloy for use in oil country tubular goods as a material suitable for severe sour service. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Ni-730. Producer or source: Nippon Steel and Sumitomo Metal Corporation.

SUMITOMO SM2050-110

Abstract Sumitomo SM2050 is a high strength nickel alloy for use in oil country tubular goods as a material suitable for severe sour service. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Ni-729. Producer or source: Nippon Steel and Sumitomo Metal Corporation.

Electron beam welding of VZh172L high-strength casting nickel alloy

The conditions of electron beam welding of VZh172L high-strength nickel alloy in the same combination and with the VZh172 deformed alloy are selected and the mechanical properties and structure of welded joints are examined.

Bi-2223 Test Coils for High Resolution NMR Magnets.

Recently, significant improvement in the strain tolerance of Bi-2223 conductor has been achieved by lamination with high strength nickel alloy. The conductor, supplied by Sumitomo Electric and designated Type HT-NX, is now commercially available in lengths sufficient for manufacture of high-homogeneity solenoids. A program to fully exploit the improved conductor properties is now underway at the National High Magnetic Field Laboratory (NHMFL). Five coils are being made, the last of which is to demonstrate an NMR measurement approaching 1 GHz and 1 ppm over 10 mm volume. In so doing, we expect to demonstrate critical current fraction, and strain similar to that expected in 30 T NMR magnets. The coils will be tested inside an existing 16 Tesla large-bore background magnet at the NHMFL. The design of the NMR demonstration coil is presented first, with expected values for field, homogeneity and strain given. A technology development program is then outlined, which includes fabrication of four test coils to test various design features, develop fabrication tooling and train personnel.

A modified Johnson-Cook model for strain rates ranging from 10-3to 105s-1

A modified Johnson-Cook model is proposed to take into account the thermally activated and viscous regimes that can be easily integrated in numerical codes. The model was calibrated using experimental data generated at temperatures ranging from 23 to 1000°C and strain rates ranging from 0.002 to 3 x 10 4 s -1 and validated through numerical simulations of symmetric Taylor tests for a pure nickel and a high strength nickel alloy.

High strain rate and high temperature behaviour of metallic materials for jet engine turbine containment

This work presents a study on the mechanical characterisation of the materials involved in air jet engine turbines. The final objective is to analyse the phenomenon of a turbine blade off failure, to verify the requirements of the case containment. The materials in the turbine are under high temperatures, ranging from 400°C to 800' C and when the fail of the blade occurs if impacts against the case, reaching strain rates up to 10 3 s -1 . To obtain the behaviour of the materials, testing at high strain rate and high temperature at one time is necessary. The experimental set-up used was a split Hopkinson pressure bar, with a high temperature furnace adapted. The bars used on the device were high strength nickel alloys with a cooling system to decrease the temperature of the measurement devices. The effect of wave dispersion due to the temperature gradient has been also studied to correct the measurements if necessary. The material tested has been the FV535 stainless steel used on the case. The full stress-strain curves at different temperatures and at strain rates up to 10 3 s -1 have been obtained. The experimental results show a marked influence of the strain rate and the temperature that cannot be neglected. The Johnson-Cook material model has been used to fit the results of the material tests.

X-ray Vision

We are fabricating optics for the hard-x-ray region using electroless nickel replication. The attraction of this process, which has been widely used elsewhere, is that the resulting full shell optics are inherently stable and thus can have very good angular resolution. The challenge with this process is to develop lightweight optics (nickel has a relatively high density of 8.9 g/cu cm), and to keep down the costs of mandrel fabrication. We accomplished the former through the development of high-strength nickel alloys that permit very thin shells without fabrication- and handling-induced deformations. For the latter, we have utilized inexpensive grinding and diamond turning to figure the mandrels and then purpose-built polishing machines to finish the surface. In-house plating tanks and a simple water-bath separation system complete the process. To date we have built shells ranging in size from 5 cm diameter to 50 cm, and with thickness down to 100 micron. For our HERO balloon program, we are fabricating over 200 iridium-coated shells, 250 microns thick, for hard-x-ray imaging up to 75 keV. Early test results on these have indicated half-power-diameters of 15 arcsec. The status of these and other hard-x-ray optics will be reviewed.

Effect of low temperatures on mechanical and physical properties of high-strength nickel alloy ÉK61-ID and stainless maraging steel ÉK49-VD

Physical and mechanical properties of high-strength nickel alloy EK61-ID and stainless maraging steel EK49-VD with reduced carbon content, which are used for fabrication of metallic seals of detachable joints (DJ) of re-usable liquid-propellant engines (LPE), are studied at cryogenic temperatures (20 – 293 K). Tests of DJ simulators with seals from these materials and subsequent field tests of LPE confirm the high operational properties of the structures.

Structure and properties of deformable nickel alloys for gas turbines

The construction of high power gas turbine installations necessitates the development and use of new high-strength heat-resistant nickel alloys for large forged turbine blades. The blade material must possess not only superior properties (high temperature strength, ductility, fatigue and thermal fatigue strength, stability in the fuel combustion products) but also the required level of metallurgical and manufacturing producibility. The results of a study of the deformable nickel alloys KhN65KVMYuTB (EK78), KhN65KMVYuB (EP800), and KhN60KVYuMB (EP957), which have substantially better properties than the alloy now used for gas turbine blades (KhN65VMTYu) (EI893), are presented in this article.

High-temperature ductility of nickel alloys type KhN55MBYu with a high iron content

In order to prepare stamped and welded structures which operate in the temperature range from 750 to −253°C there is use of high-strength dispersion-hardening nickel alloys KhN55MBYu (EP666) and KhN58MBYuD (EK61) which exhibit resistance to hot crack formation during welding and cracking of welded joints during defonnation. Alloys of this type have a high level of strength (σf = 1300 N/mm2 at 20°C) and toughness at cryogenic temperatures, and they have high resistance to plastic deformation in the temperature range for hot pressing especially in the cast condition. In order to find the optimum forging and stamping schedules for these alloys features of the change in their structure and properties in relation to the forming temperature have been studied.

High temperature brittle intergranular cracking in high strength nickel alloys undoped and doped with S, Zr, and/or B—II. Solute segregation analysis

In order to clarify the mechanism of high temperature brittle intergranular cracking in high strength nickel alloys, solute segregation at grain boundaries and on high temperature fracture surfaces has been examined by scanning Auger microscopy. Intergranular S segregation producing global embrittling effects was found to increase in the following order: alloys with low S or high S and Zr, high S and B, and high S. The grain boundaries extensively contained Ti or Zr rich sulfides in the S-doped alloys and B segregation inducing intergranular toughening in the alloy with high S and B. The alloys with low S, and high S and B showed more strongly S segregation on high temperature fracture surfaces, which was much greater compared with at grain boundaries, than with high S, and high S and Zr. The local stress intensification did not produce a remarkable S enrichment at grain boundaries except near sulfides. It is proposed that S fluxes from crack surfaces and stressed sulfides to the crack tip induce local embrittlement. The composition and temperature effects on the brittle cracking behavior are discussed in terms of the global and local embrittling effects.

High temperature brittle integranular cracking in high strength nickel alloys undoped and doped with S, Zr and/or B—I. crack growth characteristics

High temperature (823–923 K) brittle intergranular cracking behavior has been studied in γ′ strengthening nickel alloys doped with and without S, B and/or Zr. The growth rate of brittle intergranular cracks was found to be described by da/ dt = a ̇ O (K/K O ) n where K O and a ̇ O represent a transition from the crack nucleation to growth controlling process. The alloy composition and temperature produced quite different effects on K O and n. In undoped and S-doped alloys, high temperature cracking occurred at the lowest K O which strongly depends on the temperature. However, the undoped and S-doped alloys exhibited the lowest and highest values of n, respectively, almost independent of the temperature. The addition of B increased K O and decreased n more greatly than that of Zrx in alloys with high S. The alloy with high S and Zr showed the strongest temperature dependence of n in all the alloys. It has been shown by estimating the activation energy from the Arrhenius plot of ȧ O that the brittle intergranular cracking behavior is controlled by S diffusion at grain boundaries and on crack surfaces.