Influence of Rare Earth Additions to an Inconel 718 Alloy

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3035-3043
Author(s):  
Luis E. Gonzalez A. ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra ◽  
A. Ruiz
Keyword(s):  
Rare Earth ◽  
Inconel 718 ◽  
Thermomechanical Processing ◽  
Charpy Impact ◽  
Microstructural Characterization ◽  
Vacuum Induction Furnace ◽  
Inconel 718 Alloy ◽  
Impact Tests ◽  
Rare Earth Additions ◽  
The Impact

AbstractThis work analyzes the effect of rare earth additions to an Inconel 718 superalloy; for this purpose, two 8 kg ingots of a commercial composition of Inconel 718 were made in a vacuum induction furnace. One of them (In718) with the base composition and the other one (In718RE) with an addition of 0.04wt% of mischmetal (rare earths alloy based on cerium and lanthanum). Both alloys were cast into metallic molds into the vacuum chamber and let to solidify. The alloys were then solubilized for two hours at 1155 °C to eliminate deleterious phases, rolled at 1100 °C to get a reduction of 50% in thickness, then aged for 16 hours at 720 °C and 620 °C by 8 hours each. A complete microstructural characterization was undertaken by optical and electronic (SEM and TEM) microscopy and X-ray diffraction. Mechanical characterization was done by hardness tests, tensile and Charpy impact tests. Results show a slight improvement of the tensile and hardness values for the alloy with rare earth additions. However, no notorious difference was observed during the impact tests, since both alloys show the same values. These mechanical results are discussed in terms of the obtained microstructure. Both alloys are mainly composed by γ, γ´, γ´´ and carbides. It was observed that primary carbides nucleate rare earth particles; therefore, higher number of carbides and of larger size (according to a size distribution) are observed in the alloy with rare earth additions. The presence of such carbides prevents the grain growth during the thermomechanical processing which in turn improve the mechanical properties.

Effects of Rare Earth on Mechanical Properties of LZ50 Axle Steels and Its Formation Mechanism

2018 ◽  
Vol 37 (6) ◽  
pp. 509-519 ◽  
Author(s):  
Jin-ling Zhang ◽  
Yan-chong Yu ◽  
She-bin Wang ◽  
Yang Hou ◽  
Shu-chun Yin
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Impact Toughness ◽  
Fatigue Resistance ◽  
Formation Mechanism ◽  
Vacuum Induction Furnace ◽  
Lz50 Steel ◽  
Sharp Edges ◽  
Re Elements ◽  
The Impact

AbstractTo study the mechanism of rare earth (RE) elements on the mechanical properties of axle steels, trace RE were added to LZ50 axle steel, which was melted in vacuum induction furnace. By calculating the thermodynamic and kinetic of RE inclusions, the formation mechanism of inclusions was discussed. And the effects of RE elements on the microstructures and mechanical properties were investigated. The results show that RE and O elements in the molten steels diffused into the interface and increased the thickness of the liquid film. The inclusions transform into 1–3 μm spherical RE compound inclusions instead of 5 μm Al2O3-SiO2 with sharp edges. The grain sizes of the steels containing 0.0010 %～0.0026 % RE were decreased, impact toughness and fatigue resistance were improved greatly, compared with the steel without RE. The impact toughness and fatigue resistance of the LZ50 steel with the addition of 0.0010 % RE were increased by 1.65 and 2 times, respectively.

Correlating Hot Deformation Parameters with Microstructure Evolution During Thermomechanical Processing of Inconel 718 Alloy

2019 ◽  
Vol 50 (10) ◽  
pp. 4714-4731 ◽  
Author(s):  
Chirag Gupta ◽  
Jyoti S. Jha ◽  
Bhagyaraj Jayabalan ◽  
Rajat Gujrati ◽  
Alankar Alankar ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Hot Deformation ◽  
Inconel 718 ◽  
Thermomechanical Processing ◽  
Inconel 718 Alloy ◽  
Deformation Parameters

Microstructural characterization of Inconel 718 alloy after pulsed laser surface treatment at different powers

2018 ◽  
Vol 28 (8) ◽  
pp. 1530-1537 ◽  
Author(s):  
Lin-jiang CHAI ◽  
Shan-shan YUAN ◽  
Wei-jiu HUANG ◽  
Xu-sheng YANG ◽  
Fang-jun WANG ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Inconel 718 ◽  
Pulsed Laser ◽  
Microstructural Characterization ◽  
Laser Surface ◽  
Laser Surface Treatment ◽  
Inconel 718 Alloy

scholarly journals Production and characterization of dual-phase steels from an AISI 8620 steel with high Mn content

DYNA ◽  
2021 ◽  
Vol 88 (217) ◽  
pp. 42-49
Author(s):  
Dayi Gilberto Agredo Diaz ◽  
Irma Angarita Moncaleano ◽  
Rodolfo Rodríguez Baracaldo
Keyword(s):  
Charpy Impact ◽  
Microstructural Characterization ◽  
Ferrite Matrix ◽  
Martensite Phase ◽  
Mechanical Resistance ◽  
Dual Phase ◽  
Dual Phase Steels ◽  
Mn Content ◽  
Microscopy Techniques ◽  
The Impact

Dual phase steels are materials whose microstructure is composed of a ferrite matrix with martensite islands. Ferrite provides excellent ductility, while martensite increases the strength of steel, this provides a special appeal in the automotive industry. The main objective of this research is to obtain dual phase steels from AISI 8620 steel with a high Mn content, performing heat treatments in the intercritical range to obtain martensite percentages of 27, 33, 41, and 48%, respectively. Microstructural characterization is performed using optical microscopy and scanning electron microscopy techniques, the mechanical characterization is carried out using hardness, tension and charpy impact tests. The highest mechanical resistance is achieved in steel with 41% martensite phase, while the highest ductility is given for the material with 27% martensite, a fractographic analysis of all materials allowed to determine that the type of fracture presented is ductile. When the martensite fraction increases, the impact energy exhibits a decreasing behavior, while the hardness behaves in an increasing way.

scholarly journals Impact of Process Parameters on the Quality of Deep Holes Drilled in Inconel 718 Using EDD

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2298 ◽  
Author(s):  
Magdalena Machno
Keyword(s):  
Aspect Ratio ◽  
Process Parameters ◽  
Inconel 718 ◽  
Gas Turbines ◽  
Internal Surface ◽  
Dimensional Accuracy ◽  
Inconel 718 Alloy ◽  
Taper Angle ◽  
The Impact

Advanced engineering materials (e.g., nickel or titanium alloy) are being increasingly applied to produce parts of gas turbines in the aerospace industry. To improve the durability of these parts, many holes, with a length-to-diameter aspect ratio greater than 20:1, are created in their structure. The quality of the holes significantly affects the cooling process of the elements. However, it is challenging to machine materials by conventional methods. When machining a hole with a high aspect ratio, the major problem is effective flushing of the machining area, which can improve the hole’s surface integrity and dimensional accuracy. Consequently, the electro-discharge drilling (EDD) process is good alternative for this application. This paper presents the results of an analysis of the EDD of Inconel 718 alloy. An experiment was conducted to evaluate the impact of process parameters (pulse time, current amplitude, and discharge voltage) on the process’s performance (linear tool wear, taper angle, drilling speed, the hole’s aspect ratio, and surface roughness (Ra and Rz)). The results show that EDD provides us with the possibility to drill holes with an aspect ratio greater than 10:1. The results also demonstrate that holes with an aspect ratio greater than 10:1 and a small taper angle value have a significantly decreased quality of internal surface, especially at the bottom of the hole. This indicates that an insufficient amount of debris is removed from the bottom of the hole.

scholarly journals QUALITY IMPROVEMENT OF CAST CYLINDRICAL BAR OF VACUUM INDUCTION MELTING FROM INCONEL 718 ALLOY AT PJSC “RUSPOLIMET”

2019 ◽  
Vol 62 (4) ◽  
pp. 257-262
Author(s):  
A. I. Demchenko ◽  
E. N. Korzun ◽  
E. A. Chernyshov
Keyword(s):  
Casting Speed ◽  
Inconel 718 ◽  
Induction Furnace ◽  
Macro Level ◽  
Vacuum Induction Melting ◽  
Vacuum Induction Furnace ◽  
Induction Melting ◽  
Axial Zone ◽  
High Quality ◽  
Inconel 718 Alloy

The analysis of technological processes of smelting and casting of cylindrical bars from Inconel 718 alloy, obtained in a vacuum induction furnace at PJSC “Ruspolimet”, was performed. The existing technology does not ensure the production of a sound bar of the required quality due to the presence of porosity in the axial zone, and also due to liquation at the macro level of elements such as chromium, nickel, niobium. The results have shown the need to adjust the parameters of casting and solidification of bars from the Inconel 718 alloy. The task to get high-quality sound bar was set without changing the main technical parameters of production, namely: type of furnace – vacuum induction furnace with capacity of 3 tons; material of the furnace lining – ceramics based on aluminum oxide Al2O3 ; type of the casting mold – cylindrical mold for bar diameter of410 mm; diameter of crystallizer for vacuum-arc remelting –450 mm. With the use of the Thermo-Calc program (version 2017a), the solidus temperatures for the equilibrium solidification process and for the non-equilibrium process were clarified, which were 1211 °С and 1091 °С, respectively. Based on the results obtained, the casting speed (SCM LP) system corrects casting speed by reducing the diameter of the casting nozzle from 32 to28 mm and casting temperature by reducing it from 1470 to1460 °C. According to the corrected technology, a batch of bars has been smelted. From the bar of the first batch, transverse templates were selected to determine the chemical composition and longitudinal temp lates for metallographic analysis. Metallographic studies have been carried out that suggest a decrease in porosity of axial zone of the bar and a decrease in phase separation at the macro level. Based on the results obtained, the authors proposed to introduce approp riate changes in casting technology. It is shown that computer modeling of metallurgical processes of metal casting and crystallization allows developing a technology of obtaining a high-quality bar already at the first redistribution, while avoiding appearance of products that do not meet customer requirements.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

A NEW WELDING MATERIAL FOR REGENERATION IN THE WELDING TECHNOLOGY BASED ON NICKEL. ANALYSIS OF THE COMPOSITION AND PROPERTIES OF DEFORMABLE HEAT-RESISTANT HIGH-CHROMIUM NICKEL-BASED ALLOYS FOR WELDED PARTS. ANALYSIS OF EXISTING FUELLING STATIONS TYPES AND VEHICLES USING HYDROGEN, HYDROGEN PRODUCTION AND STORING METHODS

2019 ◽  
pp. 43-48
Author(s):  
Ben Nengjun ◽  
Zhou Pengfei ◽  
Oleksandr Labartkava ◽  
Mykhailo Samokhin
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Nickel Alloys ◽  
Total Content ◽  
Operating Conditions ◽  
High Temperature Strength ◽  
High Chromium ◽  
Salt Corrosion ◽  
Tcp Phases ◽  
The Impact

This work involves an analysis of high-chromium high-temperature deformable wieldable nickel alloys for use in GTE repair assemblies. It is shown that the alloys EP868 (VZh98) and Haynes 230 can be used in welded assemblies with an operating temperature of 800-1100 °C. The alloys Nimonic 81, Nimonic 91, IN 935, IN 939, and Nicrotan 2100 GT also have a high potential for use in welded assemblies. They are characterized by a combination of good weldability, high-temperature strength, and resistance to scaling. There have been conducted studies on high-temperature salt corrosion of model nickel alloys. They allowed establishing the patterns of the impact of base metal alloying with chromium, aluminum, titanium, cobalt, tungsten, molybdenum, niobium, tantalum and rare earth metals on the critical temperature of the start of salt corrosion Tcor and the alloy mass loss. It has been established that alloys with a moderate concentration (13-16%) of chromium can possess satisfactory hightemperature corrosion resistance (HTC resistance) under the operating conditions of ship GTE. The HTC resistance of CrAl-Ti alloys improves upon reaching the ratio Ti/Al ˃ 1. Meanwhile, the ratio Ti/Al ˂ 1 promotes the formation of corrosion products with low protective properties. The positive effect of tantalum on the HTC resistance of alloys is manifested at higher test temperatures than that of titanium, and the total content of molybdenum and tungsten in alloys is limited by the condition 8Mo2 – 2W2 = 89. The presence of refractory elements stabilizes the strengthening phase and prevents formation of the ɳ-phase. However, their excess promotes formation of the embrittling topologically close packed (TCP) phases and boundary carbides of an unfavorable morphology. Based on the studies of the HTC resistance, there has been identified a class of model high-temperature corrosionresistant nickel alloys with a moderate or high chromium content (30%), Ti/Al ˃ 1, and a balanced content of refractory and rare-earth elements.

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