Manufacturing of Axisymmetric Components out of Superalloys and Hard-to-Deform Steels by Roll Forming

2017 ◽  
Vol 746 ◽  
pp. 69-74 ◽  
Author(s):  
Shamil Mukhtarov ◽  
Artem Ganeev ◽  
Marsel Nagimov ◽  
Ruslan Shakhov ◽  
Vener Valitov ◽  
...  
Keyword(s):  
Physical Simulation ◽  
Isothermal Condition ◽  
Coarse Grained ◽  
Roll Forming ◽  
Basic Material ◽  
Turbine Engine ◽  
Service Properties ◽  
Fine Grained ◽  
Labor Content ◽  
Fine Grained Structure

Heat-resistant alloys are the basic material of gas turbine engine (GTE) design. Fine-grained structure in these alloys can be formed by isothermal forging and then different axisymmetric GTE components as wheels, shafts, rings can be superplastic roll formed. Examples of the superplastic and isothermal deformation use for manufacturing components out of superalloys and steels for critical applications are given. The possibility of roll forming parts as rings with a diameter up to 800 mm and as flange - cone with a diameter up to 600 mm out of superalloys (Inconel 718, EK79, EP741NP), accordingly, on SRZHD-800 and modified PNC-600 mills were showed. The macrostructure investigations of the components after the roll forming showed that the homogeneous structure was formed. The microstructure at the flange portion was fine-grained and at membrane zone was coarse-grained. Cone part was roll formed at isothermal condition from pre-stamped chromium martensitic steel sheet. Manufacturing technology of roll forming was tested by computer and physical simulation. Service properties of components were obtained by subsequent heat treatment. The effectiveness of the technology associated with increased service properties of components and decreases the labor content by automated equipment.

scholarly journals Microstructural and Mechanical Characterization of Multilayered Iron Electrodeposits

2011 ◽  
Vol 409 ◽  
pp. 474-479 ◽  
Author(s):  
C. Chan ◽  
J.L. McCrea ◽  
G. Palumbo ◽  
Uwe Erb
Keyword(s):  
Mechanical Properties ◽  
Columnar Structure ◽  
Multilayered Structure ◽  
Structure Design ◽  
Coarse Grained ◽  
Fine Grained ◽  
Microstructure And Mechanical Properties ◽  
Fine Grained Structure ◽  
Iron Coatings

Monolithic and multilayered iron electrodeposits were successfully synthesized by the pulse plating electrodeposition method. Electron microscopy and Vickers microhardness measurements were used to investigate the microstructure and mechanical properties of the iron electrodeposits produced. Two types of monolithic iron coatings were produced, one with a coarse grained, columnar structure and the other with an ultra-fine grained structure. Hall-Petch type grain size strengthening was observed in these monolithic coatings. Multilayered iron coatings composed of alternating layers of coarse grained and fine grained structures were also produced. The hardness value of the multilayered coatings falls between the hardness values for the two types of monolithic coatings produced. This study has demonstrated the possibility of applying a multilayered structure design to tailor the microstructure and mechanical properties of electrodeposited iron coatings.

Microstructure Evolution of Nickel-Based Superalloys Induced by Thermomechanical Processing - Simulation and Verification

2018 ◽  
Vol 385 ◽  
pp. 424-429 ◽  
Author(s):  
Shamil Mukhtarov ◽  
Farid Z. Utyashev ◽  
Ruslan Shakhov
Keyword(s):  
Microstructure Evolution ◽  
Thermomechanical Processing ◽  
Strain Rates ◽  
Microstructure Formation ◽  
Turbine Engine ◽  
Fine Grained ◽  
Gamma Prime ◽  
Deflected Mode ◽  
Fine Grained Structure ◽  
Prime Phase

It is known that different parts of the gas turbine engine discs are operated at different temperature and load. Therefore, it is advisable to make such components out of nickel-based superalloys with a regulated structure that provides them the best operational properties. It is important to know the thermomechanical treatment for their processing to form such structures. Research of the deformation behavior and the microstructure evolution of nickel-based superalloys were carried out on small specimens. The accumulated strains and the stress distribution in specimens were determined during simulation. It is possible to predict structure formation on the basis of a deflected mode. Verification was carried out by isothermal upsetting of specimens out of superalloys at the temperature and strain rates determined by simulation. Thermomechanical treatments of the superalloys for different microstructure formation were defined. The features of the microstructure formation are shown depending on the chemical and phase composition of the alloys. Hot deformation of the ATI Allvac 718Plus superalloy leads to dissolution of the gamma prime phase that facilitates the deformation capacity. Increasing the alloyage of superalloys, including rhenium, leads to formation of a necklace structure instead of a homogeneous fine-grained structure for less alloyed superalloys at the same strain.

Development of Ultra-Fine Grained Structure in an Al-5.4%Mg-0.5%Mn Alloy Processed by ECAP

2010 ◽  
Vol 667-669 ◽  
pp. 487-492
Author(s):  
Alla Kipelova ◽  
Ilya Nikulin ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev
Keyword(s):  
Plastic Deformation ◽  
Structure Formation ◽  
Equal Channel Angular Pressing ◽  
Microstructural Evolution ◽  
Coarse Grained ◽  
High Angle ◽  
Fine Grained ◽  
Angular Pressing ◽  
Fine Grained Structure ◽  
Zr Alloy

Microstructural changes during equal channel angular pressing (ECAP) at the temperatures of 250 and 300°C to the strains ~4, ~8 and ~12 were studied in a coarse-grained Al-5.4%Mg-0.5%Mn-0.1%Zr alloy. At a strain of ~4, the microstructural evolution is mainly characterized by the development of well-defined subgrains within interiors of initial grains and the formation of fine grains along original boundaries. Further straining leads to increase in the average misorientation angle, the fraction of high-angle grain boundaries and the fraction of new grains. However, only at 300°C, the plastic deformation to a strain of ~12 leads to the formation of almost uniform submicrocrystalline (SMC) grained structure with an average crystallites size of ~ 0.5 m. At 250°C, the microstructure remains non-uniform and consists of subgrains and new recrystallized grains. The mechanism of new SMC structure formation after ECAP is discussed.

Development of Electrically Conductive Composite Sensors with the Addition of Functional Fillers

2018 ◽  
Vol 272 ◽  
pp. 34-40 ◽  
Author(s):  
Bohdan Nešpor ◽  
Martin Nejedlík
Keyword(s):  
Thin Film ◽  
Reinforced Concrete ◽  
Film Coating ◽  
Coarse Grained ◽  
Basic Material ◽  
Real Component ◽  
Fine Grained ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Fibre Cement

The paper presents the development results of "smart" pressure-sensitive fibre-cement compositematerials as well as thin-film coating sensors designed to detect disruptions of the base materialstructure. Basic material characteristics of fine-grained and coarse-grained cement matrices wereacquired during the research. The benefits and influence of conductive inorganic components,metallic components in the form of iron fillings and steel wires, and last but not least carbon-basednon-metallic fibrous reinforcement, have been verified. Thin-film epoxy resin coatings were enrichedwith amorphous carbon black, multi-walled carbon nanotubes (MWCNT) and natural micronizedgraphite. The article closely describes the measurement of electrical and electro-mechanical(piezoresistive) properties of conductive fibre-cement composites and thin-film organic coatings in anon-loaded state, during static loading and especially during dynamic ballistic and shock tests on thefall tower. Specific electrical characteristics and the course of change in electric conductivity wasexpressed as electrical resistivity (the real component of the impedance).The performed experiments confirmed excellent electrical conductivity of dense steel-fibrereinforced composites and graphite-doped hybrid fibre reinforced concrete. The coatings showedsignificant and permanent changes in impedance in the order of tens of ohms. The newly developedfibre composites and coating layers change the impedance during destructive and non-destructivedynamic loading tests. The impedance changed not only during failure of the matrix, but also in thecase of indirect impact. Moreover, carbon reinforced concrete with incorporated graphite showedsome piezoresistive properties. These detection materials were intended to be part of a ballistic-resistant monitoring system.

scholarly journals Effect of ion nitriding by glow discharge on the physical and mechanical properties of the plastically deformed tool steel R6M5

2021 ◽  
Vol 2064 (1) ◽  
pp. 012052
Author(s):  
R K Vafin ◽  
A V Asylbaev ◽  
D V Mamontov ◽  
I D Sklizkov ◽  
G I Raab ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glow Discharge ◽  
Tool Steel ◽  
Physical And Mechanical Properties ◽  
Coarse Grained ◽  
Steel R6m5 ◽  
Ion Nitriding ◽  
Fine Grained ◽  
Fine Grained Structure

Abstract This work is devoted to the study of the effect of the duration of ion nitriding by glow discharge on the physical and mechanical properties of tool steel with different initial structure. We used specimens of R6M5 tool steel with a coarse-grained structure obtained after annealing at a temperature of 850°C and with a fine-grained structure obtained after severe plastic deformation by torsion discharge. With an increase in the duration of ion nitriding, the thickness of the hardened layer and wear resistance increase. The combination of plastic deformation with ion nitriding by glow discharge increases the adsorption and diffusion rate of the saturating element due to the creation of a highly fragmented and disoriented fine-grained structure and contributed to reduction in processing time.

scholarly journals Increasing Fatigue Life of 09Mn2Si Steel by Helical Rolling: Theoretical–Experimental Study on Governing Role of Grain Boundaries

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4531
Author(s):  
Sergey Panin ◽  
Ilya Vlasov ◽  
Pavel Maksimov ◽  
Dmitry Moiseenko ◽  
Pavlo Maruschak ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Grain Boundaries ◽  
Elastic Energy ◽  
High Strength ◽  
Coarse Grained ◽  
Material Structure ◽  
Structure Transformation ◽  
Helical Rolling ◽  
Fine Grained ◽  
Fine Grained Structure

The structure and mechanical properties of the 09Mn2Si high-strength low-alloyed steel after the five-stage helical rolling (HR) were studied. It was revealed that the fine-grained structure had been formed in the surface layer ≈ 1 mm deep as a result of severe plastic strains. In the lower layers, the “lamellar” structure had been formed, which consisted of thin elongated ferrite grains oriented in the HR direction. It was shown that the five-stage HR resulted in the increase in the steel fatigue life by more than 3.5 times under cyclic tension. The highest values of the number of cycles before failure were obtained for the samples cut from the bar core. It was demonstrated that the degree of the elastic energy dissipation in the steel samples under loading directly depended on the area of the grain boundaries as well as on the grain shapes. The fine-grained structure possessed the maximum value of the average torsional energy among all the studied samples, which caused the local material structure transformation and the decrease in the elastic energy level. This improved the crack resistance under the cyclic mechanical loading. The effect of the accumulation of the rotational strain modes at the grain boundaries was discovered, which caused the local structure transformation at the boundary zones. In the fine-grained structure, the formation of grain conglomerates was observed, which increased the values of the specific modulus of the moment of force. This could be mutually compensated due to the small sizes of grains. At the same time, the coarse-grained structures were characterized by the presence of the small number of grains with a high level of the moments of forces at their boundaries. They could result in trans-crystalline cracking.

The effect of structure and texture on pure magnesium properties

2021 ◽  
Vol 112 (1) ◽  
pp. 57-62
Author(s):  
Bartosz Sułkowski
Keyword(s):  
Deformation Mode ◽  
Pure Magnesium ◽  
Coarse Grained ◽  
Initial Structure ◽  
Fine Grained ◽  
Compression Direction ◽  
First Case ◽  
Axis Parallel ◽  
Fine Grained Structure ◽  
Deformation Modes

Abstract Deformation modes and twin hardening of pure magnesium under compression in respect of the initial structure and texture were studied in the present work. In general, samples had two types of texture with different alignment of c-axis in respect to a compression direction. In the first case, most of the grains have the c-axis parallel to the compression direction and in the second case, the c-axis was perpendicular with the compression direction. It was found that coarse grained material deformed by slip despite the type of the texture, while the fine grained samples, with c-axis perpendicular to the compression direction, deformed by twinning. The samples which deform by twinning exhibited the highest yield point. It was concluded that combination of the fine grained structure and hard type texture components may introduce twinning as the main deformation mode and may increase the mechanical properties of magnesium and its alloys. The model for twin induced hardening is proposed where twins act as the grain refinement factor.

scholarly journals The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3995 ◽  
Author(s):  
Radosław Łyszkowski ◽  
Magdalena Łazińska ◽  
Dariusz Zasada
Keyword(s):  
Pure Copper ◽  
Secondary Recrystallization ◽  
Extrusion Process ◽  
Exothermic Peak ◽  
Coarse Grained ◽  
Scanning Calorimetry ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Fine Grained Material ◽  
Experimental Trials

A new cross-channel extrusion (CCE) method with the application of a back pressure (BP) is proposed and experimentally tested. The introduction of pressure blocks the free flow of material by using an additional set of pistons, which prevents the loss of consistency. The paper presents results of experimental trials of CCE process. Between one and eight passes of CCE with and without a BP were applied to pure copper billets to refine their initial coarse-grained microstructure at room temperature. It was found that processing by CCE results in the formation of a lamellar structure along the extruded axis and the fine-grained structure in the remaining volume. The material exhibited dynamic recrystallization, which results in the formation of 0.5- to 2-μm grains after one pass and 2- to 8-μm grains after four CCE passes. The fine-grained material had YS of 390-415 MPa. An increase in the microhardness from 70 to 130 HV02 after one pass and then a decrease after four passes were observed. This might indicate that secondary recrystallization and selective grain growth occur, because an exothermic peak (158.5 °C, 53 ± 2.1 J/mol) was observed during DSC (differential scanning calorimetry) testing. The resistivity of the once deformed copper significantly decreases, while its further processing causes the resistivity to increase.

scholarly journals Superplastic Roll Forming of Axial Symmetric Articles from Superalloys

2011 ◽  
Vol 278 ◽  
pp. 301-305 ◽  
Author(s):  
Farid Z. Utyashev ◽  
Shamil Kh. Mukhtarov ◽  
Ayrat A. Nazarov ◽  
Radik R. Mulyukov
Keyword(s):  
Gas Turbine ◽  
Thin Layers ◽  
New Method ◽  
Coarse Grained ◽  
Roll Forming ◽  
Microstructure Design ◽  
Turbine Engine ◽  
Ultrafine Grains ◽  
The Third ◽  
Engine Components

A new method of microstructure design in axisymmetric gas turbine engine components made of superalloys is proposed. The method is based on obtaining three types of microstructures by means of superplastic roll forming: coarse-grained one with coherent nano-sized precipitates of the  phase, the second with ultrafine grains of both phases and the third combining coarse deformed matrix grains surrounded by thin layers of fine matrix grains and coarsened precipitates of  phase.

Correlation between dislocation, grain boundary and interface of duplex SS in stress corrosion cracking(SCC)

1990 ◽  
Vol 48 (4) ◽  
pp. 928-929
Author(s):  
Wang Zheng-fang ◽  
Z.F. Wang
Keyword(s):  
Stainless Steel ◽  
Thermal Cycle ◽  
Secondary Phase ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
Test Environment ◽  
Fine Grained ◽  
Evaluation Test ◽  
Welding Thermal Cycle ◽  
Micro Analysis

The main purpose of this study highlights on the evaluation of chloride SCC resistance of the material,duplex stainless steel,OOCr18Ni5Mo3Si2 (18-5Mo) and its welded coarse grained zone(CGZ).18-5Mo is a dual phases (A+F) stainless steel with yield strength:512N/mm2 .The proportion of secondary Phase(A phase) accounts for 30-35% of the total with fine grained and homogeneously distributed A and F phases(Fig.1).After being welded by a specific welding thermal cycle to the material,i.e. Tmax=1350°C and t8/5=20s,microstructure may change from fine grained morphology to coarse grained morphology and from homogeneously distributed of A phase to a concentration of A phase(Fig.2).Meanwhile,the proportion of A phase reduced from 35% to 5-10°o.For this reason it is known as welded coarse grained zone(CGZ).In association with difference of microstructure between base metal and welded CGZ,so chloride SCC resistance also differ from each other.Test procedures:Constant load tensile test(CLTT) were performed for recording Esce-t curve by which corrosion cracking growth can be described, tf,fractured time,can also be recorded by the test which is taken as a electrochemical behavior and mechanical property for SCC resistance evaluation. Test environment:143°C boiling 42%MgCl2 solution is used.Besides, micro analysis were conducted with light microscopy(LM),SEM,TEM,and Auger energy spectrum(AES) so as to reveal the correlation between the data generated by the CLTT results and micro analysis.

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