Hastelloy C-276 Alloy Research Articles

Influence of process parameters on forming quality of largesize nickel-based alloy tubes

In order to improve the forming quality of largesize nickel-based alloy chemical tubes, the influence of different tube specifications and mandrel/tube clearances on the bending forming quality of largesize Hastelloy C-276 alloy tubes was studied. A finite element (FE) analysis model for NC rotary drawing bending (RDB) was established and verified. The results show that with the increasement of the clearance, the wall-thinning ratio [Formula: see text] of different tube specifications gradually decreases, and the wall-thickening ratio [Formula: see text] and ovality [Formula: see text] gradually increase. As the measuring angle increases, the [Formula: see text] of different specifications initially increases and then decreases. The [Formula: see text] exhibits a trend of initially increasing and then decreasing. It is reasonable to take about 1/8 of the wall thickness t for the mandrel/tube clearance. It is of great significance for guiding the bending forming of largesize nickel-based alloy chemical tubes and development of intelligent forming equipment.

Some studies on optimization of process parameters for wire ARC additive manufacturing of Hastelloy C276 using GRA-GWO hybrid techniques

Wire arc additive manufacturing (WAAM) has become an inevitable manufacturing technology in the present decade. This article discusses optimizing process variables for fabricating Hastelloy C276 alloy via WAAM. The controlling parameters are gas flow rate (GFR), deposition speed, and welding current, while the depth of penetration, top reinforcement, and bead width are the output parameters considered for optimization. The magnitude of interaction effects between control parameters is equal to that of individual impact on the weld bead characteristics evident from analysis of variance results. Grey relational analysis revealed the optimal parameters (trial 1 with I = 120 A, S = 200 mm/min, GFR = 15 L/min) chosen through its robust optimization procedure. S/N ratio analysis revealed the most influencing parameters at the factor level (current level 1, speed level 1). The Grey Wolf optimizer (GWO) algorithm was used as a precision and confirmation experiment. The GWO optimization results further confirmed that the GFR of 15 L/min, speed of 200 mm/min, and current of 120 A were the optimized parameters used in this design space. Further, normal probability plots with minimal error of around 1% reinforce that the parameters chosen in this design space are well within the optimal limits. The surface plots reported the relationship and variation between control and resulting factors.

Edge cracking behavior of Y2O3 films based on the stress intensity factor

Hastelloy C-276 alloy is the preferred substrate for YBa2Cu3O7-δ (YBCO) coated conductors prepared by Ion-beam-assisted deposition (IBAD) route, but its surface is too rough to meet application requirements. Y(CH3COO)3·4H2O precursor solution has a low flattening efficiency, and its film edges are prone to crack formations. In this paper, a model for the stress intensity factor was established to study the effect of the presence of cracks on film stress. The simulation results showed that increasing the coating thickness reduced the overall stress, but increased the stress concentration at the crack. The larger bottom layer defects also made it easier for cracks to be generated. Then, 10-m long Hastelloy C-276/Y2O3 strips were prepared by colloidal-solution deposition planarization (CSDP), with an average surface roughness Rq of 0.427 and only 10 coating layers. This improved the flattening efficiency by 40 %, and a CeO2 layer with a good biaxial texture was finally prepared.

Effects of Different Die Metals on the Performance and Friction and Wear of Composite Materials during the Extrusion Process.

Extrusion technology is widely utilized in the rubber processing industry, with the extruder serving as the core equipment. As mixed rubber enters the extruder, it undergoes conveyance and plasticization, ultimately forming specific shapes and dimensions upon extrusion. The extruder head is a crucial component, playing a key role in achieving the final product's required size and shape. Factors such as its structure, materials, and manufacturing processes significantly impact the efficiency, product quality, and sustainability of the extrusion process. However, prolonged operation leads to severe wear of the extruder head, adversely affecting rubber product quality. Additionally, extruder head processing poses challenges, with maintenance and repair being complex procedures. Therefore, exploring a wear-resistant, long-lasting metal material for the extruder head without compromising mixed rubber performance is essential. This study focuses on severely worn extruder head metal materials, comparing wear levels after friction with STELLITE 6 alloy, Hastelloy C-276 alloy, 38CrMoAlA, and tungsten carbide with composite rubber. Results show that compared to the NR/BR composite material after Hastelloy C-276 alloy friction, rubber Payne effect increased by 4.4% (38CrMoAl), 3.2% (STELLITE 6), and 4.6% (tungsten carbide). Similarly, rubber dispersion decreased by 9.4% (38CrMoAl), 4.7% (STELLITE 6), and 9.8% (tungsten carbide). Rolling resistance increased by 18.1% (38CrMoAl), 16% (STELLITE 6), and 23.4% (tungsten carbide). Friction coefficient increased by 3.5% (38CrMoAl), 2.8% (STELLITE 6), and 4.3% (tungsten carbide). Wear volume increased by 39.3% (38CrMoAl), 45.3% (STELLITE 6), and 48.9% (tungsten carbide). Specifically, using Hastelloy C-276 alloy as the extruder head metal material yields the best NR/BR composite material dispersion, highest ten times tear strength, excellent anti-wet skid resistance, and minimum rolling resistance. Conversely, using the other alloys results in varying reductions in the physical and mechanical properties of NR/BR composite materials. This research is crucial for improving rubber product quality and extending extruder head lifespan.

Microstructure development and cavitation erosion resistance enhancement of additive manufactured Hastelloy C276 alloy coating on martensitic stainless–steel via directed energy deposition

In this study, a Hastelloy C276 coating was prepared on a martensitic stainless-steel substrate using laser melting deposition, aiming at obtaining a coating with high resistance to cavitation erosion. The coating is up to 600 μm thick, and the grain morphology of the coating exhibits a progression from bottom to top, transitioning from cellular to columnar and ultimately to equiaxed grains. Additionally, the grains grow at a specific angle to the substrate plane, following the direction of the heat source. A 200 μm thick compositional mixing zone is formed at the interface of the substrate and the coating, in which the coating elements and substrate elements mutually permeate and form a stable metallurgical bond. The microhardness of the coating is measured as 334.4 HV0.05, signifying a substantial improvement of 33.2 % compared to the substrate. The cavitation erosion process of the coating can be classified into three stages: incubation, accumulation, and stabilization. The material spalling damage caused by cavitation erosion progresses in a fatigued manner, and the coating demonstrates considerably enhanced resistance to cavitation erosion compared to the substrate.

Hot Deformation Behavior of Hastelloy C276 Alloy: Microstructural Variation and Constitutive Models.

Isothermal deformation experiments of the Hastelloy C276 alloy were executed using the Gleeble-3500 hot simulator at a temperature range of 1000-1150 °C and a strain rate range of 0.01-10 s-1. Microstructural evolution mechanisms were analyzed via transmission electron microscope (TEM) and electron backscatter diffraction (EBSD). Results reveal that the influences of hot compression parameters on the microstructure variation features and flow behaviors of the Hastelloy C276 alloy were significant. The intense strain hardening (SH) effects caused by the accumulation of substructures were promoted when the strain rates were increased, and true stresses exhibited a notable increasing tendency. However, the apparent DRV effects caused by the annihilation of substructures and the increasingly dynamic recrystallization (DRX) behaviors occurred at high compressed temperature, inducing the reduction in true stresses. In addition, a physical-based (PB) constitutive model and a long short-term memory (LSTM) model optimized using the particle swarm optimization (PSO) algorithm were established to predict the flow behavior of Hastelloy C276 alloy. The smaller average absolute relative error and greater relation coefficient suggest that the LSTM model possesses a higher forecasting accuracy than the PB model.

The hot deformation behaviors and constitutive modeling of Hastelloy C276

Hastelloy C276 is widely used in the new generation of nuclear power plants, and hot deformation is the optimum way to form the C276 part. In this investigation, the hot deformation and constitutive modeling of Hastelloy C276 alloy are researched, and the processing maps are drawn. The results show that strain rate and hot deformation temperature have remarkable impacts on the deformation behaviors of the Hastelloy C276 alloy. The yield behavior and the flow stress are predicted based on the Arrhenius constitutive equation, and the correlation coefficients are 0.9613 and 0.9837, indicating the high prediction ability of the established constitutive equation. Rising the deformation temperature can decrease the unstable deformation area, and the studied alloy can be deformed at low strain rates. With the increased strain rate, flow localization occurs, which is not suitable for the hot deformation.

Stabilised mechanical properties in Ni-based Hastelloy C276 alloy by additive manufacturing under different heat inputs incorporated with active interlayer temperature control

In this study, a Ni-based Hastelloy C276 alloy was prepared using cold metal transfer (CMT)-based directed energy deposition (DED) under different heat inputs with a zig-zag deposition path, integrated with active cooling and interlayer temperature control. Analogous mechanical properties were obtained for the fabricated alloys under different heat inputs (276, 368 and 553 J/mm) through effective interlayer temperature control. Such a broad processing window facilitates the large-scale industrial manufacturing and application of Hastelloy C276 by DED. Nevertheless, the lower heat input appears to slightly refine the microstructure and decrease the mechanical anisotropy of manufactured alloys, which is ascribed to combined effects of the manipulated bulk texture, refined dendrite arm spacing and reduced chemical segregation under lower heat input. Despite the variations of geometrically necessary dislocation (GND) densities with heat inputs, no significant change was observed in the average total dislocation density (TDD) in the microstructure of all samples as suggested by the peak profile analysis of Synchrotron X-ray diffraction data, which is advantageous for lowering the solidification cracking susceptibility. Moreover, all as-fabricated alloys present a typical strong fibre-type (200) crystallographic bulk texture measured by neutron diffraction, while such texture was relatively weaker in the lowest heat input condition. This work provides a reliable approach for stable additive manufacturing of Hastelloy C276 alloy, and innovatively presents rationales of stabilised properties based on the obtained insights into microstructure and bulk texture developments in a wide observation range by various techniques.

Investigation of the characteristic properties of graphene-based nanofluid and its effect on the turning performance of Hastelloy C276 alloy

The present paper addresses an ecological machining method in turning Hastelloy C 276 Nickel alloy under different conditions such as dry, oil with least quantity lubrication (LQL), and graphene-based nanofluid LQL (NFLQL) by changing the cutting speed (31, 46, and 62 m/min) and feed rate (0.1, 0.15 and 0.2 mm/rev). Four machining responses were studied namely: surface roughness, tool wear, cutting temperature, and chip thickness. The wettability, pH value, and stability of the nanofluids were assessed prior to the machining process. The output revealed that the usage of NFLQL enhanced the machining performance in contrast to the oil LQL and dry conditions. The average reduction in the surface roughness with NFLQL condition is about 66% compared to dry machining. In addition, NFLQL gives the lowest cutting temperature (40 °C), flank wear (0.053 mm), and chip thickness (0.16 mm) respectively. In a nutshell, the effective cooling and lubrication ability of NFLQL has made significant contributions to smoother machining.

Edge cracking behavior of Y2O3 coatings by the solution deposition planarization method

As an efficient flattening technique for surface smoothing, solution deposition planarization (SDP) has recently drawn more attention as a fabrication method for second generation high temperature superconducting (2G-HTS) tapes. However, at present, it is still challenging to achieve edge crack-free surfaces while preparing a Y2O3 coating via SDP processing, especially during drying and heat treatment. Experimental results show that as the colloidal dispersion is coated and dried on a nonporous rigid substrate, the enormous stresses developed during the drying process can fracture the thin film. The finite element simulation results show that coating thickness, which is affected by the differences in pulling rate and solution concentration, is a critical factor determining the crack sies may be initiated. After optimizing the coating parameters, a 10-m long Hastelloy C-276 alloy base was successfully prepared. The average value of Ra was 1.28 nm, which is less than 5 nm (5 × 5 μm2), satisfying the industrial requirements for the preparation of superconducting materials using the IBAD (lon Beam Assisted Deposition) technology route.

Microstructural characterisation and hardness assessment of wire arc cladded Hastelloy C276 on creep resistant steel P91

A new structure with nickel-based Hastelloy C276 alloy cladding on creep resistant steel P91 was developed in this study for nuclear applications. The microstructure, including precipitation and grain size, boundaries, orientation and hardness distribution of cladding structures with/without post heat treatment were explored using a range of microscopy techniques and hardness testing. The results show that the as-cladded structure exhibits highly hierarchical heterogeneity, which is mainly related to the remarkably coarse-grained microstructure in the heat-affected zone on the steel side, and typically columnar dendrites formed on the Hastelloy side. After tempering heat treatment, the specimen exhibits re-orientated grains and homogenized microstructure. Meanwhile, the ratio of high angle grain boundaries (HAGBs) in steel regions significantly increases, and the hardness values turn even distribution. This study achieves a sound metallurgical bonding between two structural materials and offers insights into the development of dissimilar metal components with in-site specific properties.

Microevolution of grain boundary character distribution in Hastelloy C-276 during the annealing process

Grain boundary character distribution and disconnectivity of random boundaries were observed “in-situ” in the Hastelloy C-276 alloy sample through thermomechanical processing. The role of Σ3 boundaries in microstructural evolution of grain boundary character distribution was analyzed by electron back-scattered diffraction (EBSD) and the mechanisms of grain boundary engineering (GBE) during annealing were elucidated. The results showed that the fraction of Σ3n boundaries (including Σ3 boundaries) consistently increased in number with annealing time; however, the Σ3 boundaries had different effects on the disconnectivity of random boundaries because of their variants, i.e., coherent and incoherent Σ3 boundaries. At the initial annealing stage, new incoherent Σ3 boundaries were generated, according to the “Σ3 regeneration mechanism” model; Σ9 and Σ27 boundaries appeared and increased in number with increasing Σ3 boundary interactions. These incoherent Σ3 boundaries could disrupt the connectivity of the random grain boundaries and form large clusters. However, at the annealing stage, some incoherent Σ3 boundaries were annihilated, and new coherent ones emerged. As a result, the random grain boundary network evolved by obtaining significant connectivity with larger clusters, attributed to the reduction of the incoherent Σ3 boundaries. This implies that the incoherent Σ3 boundaries play an important role in the optimization of grain boundary engineering.

Tailoring the surface finish, dendritic microstructure and mechanical properties of wire arc additively manufactured Hastelloy C276 alloy by magnetic arc oscillation

In this study, magnetic arc oscillation (MAO) at three different frequencies (5 Hz, 10 Hz and 20 Hz) was applied during deposition of a Ni-base alloy, Hastelloy C276, by wire arc additive manufacturing (WAAM). The microstructure, surface finish and the mechanical properties of WAAM deposited Hastelloy C276 alloy samples with MAO were investigated and compared with the counterpart without the application of MAO. On-line monitoring of the arc movement and molten pool morphologies showed that the incorporation of MAO during WAAM may reduce the arc density during deposition, leading to a decrease in the solidification time. This, in turn, improved the surface accuracy of the as-built alloys. Furthermore, through the application of MAO, the dendrites exhibited a higher variety of growth orientations, and reduced dendrite arm spacings (DAS). The MAO at 5 Hz appeared to enhance the mechanical properties of the produced alloy, while the application at the higher frequencies of 10 Hz and 20 Hz led to less pronounced effects on the mechanical performance improvement. This study enhanced our understanding of the correlation of MAO processing-dendritic microstructure development-mechanical property for the Hastelloy C276 alloy prepared by WAAM, providing guidelines for the utilization of the MAO approach for tailoring the microstructure and the mechanical properties of WAAM produced alloys.

Evaluation of solidification cracking of Ni-based alloy dissimilar welds based on Trans-Varestraint test

This study aims to evaluate the weldability of dissimilar welds with the Inconel 625 and the Hastelloy C-276 nickel-based alloys deposited on ASTM A36 and AISI 1045 carbon steel plates. The welds were carried out by the GMAW process and evaluated by the Trans-Varestraint test. The test results were statistically evaluated, and Fusion Zone solidification processes were simulated in JMatPro software using several dilution levels. The analysis of variance (ANOVA) test results showed that the two different base metals did not affect the weldability of Inconel 625. However, the Hastelloy C-276 alloy showed a significant drop in weldability with the AISI 1045 steel compared to the ASTM A36. The results of the Hastelloy C-276 as the filler metal and the AISI 1045 steel as the base metal showed greater susceptibility to solidification cracking than all the other pairs tested, according to the Trans-Varestraint test. Moreover, the ANOVA test results indicated that the different heat input levels did not influence the sets’ weldability; this was probably because there was only a tiny variation in the dilution levels. The solidification process simulation indicates that higher dilution levels promote the precipitation of a larger secondary phase fraction.

Effects of post heat treatment on the microstructure and mechanical properties of wire arc additively manufactured Hastelloy C276 alloy

Post-processing is often inevitable for most additively manufactured components in order to improve material properties and product quality. In this study, the influence of post-heat treatments (PHTs) at 871 °C and 1177 °C on the microstructure and mechanical properties of a nickel-base Hastelloy C276 alloy prepared using wire arc additive manufacturing (WAAM) were investigated. The results showed that after a PHT at 871 °C, the as-built alloy was strengthened due to the formation of a large amount of Mo-rich nano-sized μ phase in the interdendritic areas. This was at the expense of a significant ductility loss. In contrast, no μ phase precipitates were observed after PHT at 1177 °C. Furthermore, the 1177 °C treatment led to the dissolution of the Mo-rich p phase which was present in the as-built sample, increased solid-solution strengthening, and improvements in both strength and ductility concurrently. This study enables an improved understanding of post-processing-microstructure-property inter-relationships for Hastelloy C276 alloy prepared by WAAM, providing guidelines for further microstructure optimization through PHT to improve the material's mechanical properties.

Control of deformation and annealing process to produce incoherent Σ3 boundaries in Hastelloy C-276 alloy

Hastelloy C-276 samples were cold-rolled with their thickness reduction of 7.5% and 15%, and then annealed at 1100 °C for 5–60 min in solid solution. The grain boundary character distributions (GBCDs) were characterized by a technique of electron back scatter diffraction (EBSD). Results indicated that, more convoluted Σ3 boundaries (i.e. incoherent Ʃ3 boundaries) are generated by reasonable annealing time in low strain (7.5%) sample during strain-induced boundary migration (SIBM) processing. They can induce higher Ʃ3n fraction and activate more interactions between special boundaries for GBE. Instead, more coherent Ʃ3 boundaries were produced by moderate strain (15%) and annealing treatment with the occurrence of static recrystallization (SRX). The recrystallized fine grains possess fewer incoherent Ʃ3 boundaries cannot promote to get more multiple twinning for optimization of GBCD. Therefore, reasonable deformation and annealing treatment parameters lead to more incoherent Ʃ3 boundaries would play an important role in the optimization of GBE.

A Review on Influencing Welding Parameters of Super Alloys

Manufacturing industries play a vibrant role in economic development and significant growth of a country. Among all different industries, sheet metal industry is irreplaceable in our routine life. Sheet metal applications include in automobiles, aircrafts, computer panels, building roofs etc. Various manufacturing process of sheet metal industry consists of shearing, bending, welding and deep drawing. Welding is one of the vital process in engineering business. Welding is the best operative method of joining similar and dissimilar components together. Choice of influencing process parameters is very much critical in welding for the purpose of obtaining good quality weldments with preferred mechanical properties and enhanced serviceability. This is impossible with single welding method that yields the optimum weld in all conditions. The choice of welding process depends upon the service environment, time, cost, and deposition rate. Superalloy is an alloy having greater mechanical strength and high corrosion resistance in high temperature applications. Superalloys are of, Nickel, Cobalt and Iron built possessing the crystal structure of Face Centered Cubic (FCC) austenitic. Typical examples of super alloys include Inconel, Hastelloy, Waspaloy, Rene alloys, Incoloy. Among these, Hastelloy is a nickel based superalloy containing the major proportion as Nickel 57%, Chromium 15.5% and Molybdenum 16% with the remaining in smaller proportions. Hastelloys are employed by the chemical industries for their Corrosion-Resistant property. The characteristics of Hastelloy include high resistance to localized corrosion in welding and fabrication. Hastelloy are of different grades optimised for specific purpose. Hastelloy alloys of “C-type” alloys are the most versatile. Hastelloy C276 alloy is a nickel alloy engaged in petro chemical and related industries possessing corrosive chemicals. Hastelloy C276 is ductile in nature, suitable for welding, forming and has high resistance to corrosion. Hastelloy C276 alloy is welded by the fusion welding process. The low quantity of carbon existence prevents carbide precipitation to keep resistance to inter granular attack in thermally affected zones. Every industry requires to attain a good quality of weld with great productivity and low processing cost with commanding weld joint.

Flow stress prediction of Hastelloy C-276 alloy using modified Zerilli−Armstrong, Johnson−Cook and Arrhenius-type constitutive models

Abstract To better understand the hot deformation behaviors of Hastelloy C-276 alloy under elevated temperatures, hot tensile tests were carried out in the temperature range of 1223−1423 K and the strain rate range of 0.01−10 s−1, respectively. Based on the modified Zerilli−Armstrong, modified Johnson-Cook, and strain-compensated Arrhenius-type models, three constitutive equations were established to describe the high-temperature flow stress of this alloy. Meanwhile, the predictability of the obtained models was evaluated by the calculation of correlation coefficients (r) and absolute errors (Δ), where the values of r for the modified Zerilli−Armstrong, Johnson−Cook, and Arrhenius-type constitutive models were computed to be 0.935, 0.968 and 0.984, and the values of Δ were calculated to be 13.4%, 10.5% and 6.7%, respectively. Moreover, the experimental and predicted flow stresses were compared in the strain range of 0.1−0.5, the results further indicated that the obtained modified Arrhenius-type model possessed better predictability on hot flow behavior of Hastelloy C-276.

Microstructure, mechanical and corrosion properties of TIG welded Hastelloy C-276

Abstract Hastelloy C-276 is a corrosion resistant nickel based solid solution hardened industrial alloy which has superior mechanical and corrosion properties. In this study, Hastelloy C-276 alloy was welded via the GTAW (Gas tungsten arc welding) method using ERNiCrMo-4 filler metal. Tensile, bending and notch impact tests were performed to determine the mechanical properties. The microstructure of the weld metal was investigated by light microscopy (LM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The impact toughness values of the heat affected zone (HAZ) showed a better performance than those of the weld metal. In addition, the corrosion properties of the weld metal and the base material were investigated by potentiodynamic polarization tests. Electrochemical potentiodynamic polarization parameters were determined according to corrosion behavior and microstructure properties. In particular, the corrosion rate of the weld metal increased because of the Mo-rich phases deposited in the weld metal microstructure.

Microstructure, mechanical and corrosion properties of TIG welded Hastelloy C-276

Abstract Hastelloy C-276 is a corrosion resistant nickel based solid solution hardened industrial alloy which has superior mechanical and corrosion properties. In this study, Hastelloy C-276 alloy was welded via the GTAW (Gas tungsten arc welding) method using ERNiCrMo-4 filler metal. Tensile, bending and notch impact tests were performed to determine the mechanical properties. The microstructure of the weld metal was investigated by light microscopy (LM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The impact toughness values of the heat affected zone (HAZ) showed a better performance than those of the weld metal. In addition, the corrosion properties of the weld metal and the base material were investigated by potentiodynamic polarization tests. Electrochemical potentiodynamic polarization parameters were determined according to corrosion behavior and microstructure properties. In particular, the corrosion rate of the weld metal increased because of the Mo-rich phases deposited in the weld metal microstructure.