Higher Solution Temperature Research Articles

Influence of solution temperature on microstructure and high temperature creep properties of DZ125 nickel-base alloy

ABSTRACT By performing solution treatment at various temperatures, creep property measurements, and microstructural observations, the influence of the solution temperature on the microstructure uniformity and high-temperature creep properties of the DZ125 nickel-based alloy were studied. The results showed that after the solution and aging treatment of the alloy under a relatively low temperature of 1230°C, microstructure inhomogeneities in the dendrite/inter-dendrite regions appeared, and the coarse g¢ phase and eutectic structure in the casted alloy were not removed. The processing and aging treatment of the alloy under a higher solution temperature of 1260°C caused the coarse g¢ phase and eutectic structure within the inter-dendritic area of the alloy to be eliminated, thus enabling the uniform distribution of the fine cubic g¢ phase with a high-volume fraction between the dendrite/inter-dendrite regions and the enhancement of the creep performance of the alloy.

Application of a heterogeneous physical model for the adsorption of Cd2+, Ni2+, Zn2+ and Cu2+ ions on flamboyant pods functionalized with citric acid

• Functionalization of flamboyant pods with citric acid was used to remove Cd 2+ , Ni 2+ , Zn 2+ and Cu 2+ . • Carboxylic and phenol functionalities played an important rolein heavy metal adsorption. • Endothermic adsorption of tested heavy metals was associated to physisorption. • Adsorption mechanism was analyzed via a physical model with two adsorption sites. A heterogeneous physical model with two bindings sites (HPMTBS) was successfully used to explain the adsorption of Cd 2+ , Ni 2+ , Zn 2+ , and Cu 2+ ions on flamboyant pods functionalized with citric acid. Experimental results and statistical physics modeling showed that carboxylic and phenolic functionalities of this adsorbent played a relevant role for the adsorption of Cd 2+ , Ni 2+ , Zn 2+ , and Cu 2+ ions. Calculations performed with HPMTBS suggested that the removal of these cations was a multi-ionic adsorption process at tested operating conditions. This adsorbent was more effective to remove Cd 2+ , Ni 2+ , Zn 2+ and Cu 2+ ions at high solution temperatures thus indicating an endothermic process with adsorption energies ranging from 20.3 to 29.5 kJ/mol, which were associated to physisorption. The total adsorption capacities varied from 0.10 to 0.32, 0.28 to 0.39, 0.19 to 0.25 and 0.20 to 0.31 mmol/g for Cd 2+ , Ni 2+ , Zn 2+ and Cu 2+ , respectively. This difference in adsorption capacities could be attributed to the ionic radius of tested adsorbates. This functionalized biomass can be considered as an alternative adsorbent for facing water pollution by heavy metal ions.

Depolymerization of Technical-Grade Polyamide 66 and Polyurethane Materials through Hydrogenation.

Chemical recycling provides a promising solution to utilize plastic waste. Here, a catalytic hydrogenative depolymerization of polyamide 66 (PA 66) and polyurethane (PU) was developed. The system employed Ru pincer complexes at high temperature (200 °C) in THF solution, and even technical-grade polymers could be hydrogenated with satisfactory yields under these conditions. A comparison of the system with some known heterogeneous catalysts as well as catalyst poisoning tests supported the homogeneity of the system. These results demonstrate the potential of chemical recycling to regain building blocks for polymers and will be interesting for the further development of polymer hydrogenation.

Thermal Activation of Peracetic Acid in Aquatic Solution: The Mechanism and Application to Degrade Sulfamethoxazole

Chemical oxidation using peracetic acid (PAA) can be enhanced by activation with the formation of reactive species such as organic radicals (R-O•) and HO•. Thermal activation is an alternative way for PAA activation, which was first applied to degrade micropollutants in this study. PAA is easily decomposed by heat via both radical and nonradical pathways. Our experimental results suggest that a series of reactive species including R-O•, HO•, and 1O2 can be produced through the thermal decomposition of PAA. Sulfamethoxazole (SMX), a typical sulfa drug, can be effectively removed by the thermoactivated PAA process under conditions of neutral pH. R-O• including CH3C(O)O• and CH3C(O)OO• has been shown to play a primary role in the degradation of SMX followed by direct PAA oxidation in the thermoactivated PAA process. Both higher temperature (60 °C) and higher PAA dose benefit SMX degradation, while coexisting H2O2 inhibits SMX degradation in the thermoactivated PAA process. With a variation of solution pH, conditions near a neutral value show the best performance of this process in SMX degradation. Based on the identified intermediates, transformation of SMX was proposed to undergo oxidation of the amine group and oxidative coupling reactions. This study definitively illustrates the PAA decomposition pathways at high temperature in aquatic solution and addresses the possibility of the thermoactivated PAA process for contaminant destruction, demonstrating this process to be a feasible advanced oxidation process.

Effects of solution-aging treatments on microstructure features, mechanical properties and damage behaviors of additive manufactured Ti–6Al–4V alloy

Hot isostatic pressing (HIPing) treatment was generally carried out to eliminate possible defects and to homogenize the microstructure for Ti–6Al–4V alloy fabricated by the Electron beam rapid manufacturing (EBRM) process. But the HIPed alloy with relative coarse lamellar microstructure exhibited a low strength compared to the as-built one. Post solution-aging treatments were necessary to optimize the HIPed alloy's tensile properties. So far, the relationship between the heat-treated microstructure features and corresponding mechanical properties of EBRM-produced Ti–6Al–4V has not been completely understood. Therefore, in the present work, solution-aging treatments under various solution temperatures (930 °C–990 °C) were applied to the HIPed Ti–6Al–4V produced by the EBRM, and the corresponding microstructures and mechanical properties were investigated. The results showed that solution-aging treatments could increase the HIPed alloy's tensile strength but decrease its ductility. With increasing solution temperature, the tensile strength presented an upward tendency until to 980 °C, whereas a decrease after 990 °C solution treatment. The variation in tensile properties was caused by the microstructures evolved with solution temperatures. In-situ tensile results showed that the deformation and damage behaviors of the alloy were also highly affected by the solution temperatures. Owning to a decrease of content of the αp with increase of solution temperature, the alloy at high solution temperature presented superior resistance of crack initiation but inferior resistance of crack growth than that at low solution temperature.

Gas separation and water desalination performance of defect-free interfacially polymerized para-linked polyamide thin-film composite membranes

The introduction of interfacially polymerized (IP) polyamide thin-film composite (TFC) membranes in the 1980s revolutionized the reverse osmosis desalination industry. However, IP-derived TFCs have not achieved industrial success for gas separation applications due to the presence of membrane defects in their dry state. In this work, we report defect-free crosslinked polyamide thin-film composite membranes prepared from para-substituted aromatic and cycloaliphatic diamines, p-phenylenediamine (PPD) and piperazine (PIP), reacted with trimesoyl chloride (TMC). The key parameters in our modified IP process to mitigate defects are long reaction time (~5 min) and high organic solution temperature (100 °C). The gas separation and desalination properties of the para-linked polyamide membranes were compared to previously reported polyamide TFCs made from meta-phenylenediamine (MPD) and TMC. The gas- and water permeances of the TFCs increased in the order: MPD-TMC < PPD-TMC < PIP-TMC, whereas gas-pair selectivities and salt rejections followed the opposite sequential trend: MPD-TMC > PPD-TMC ≥ PIP-TMC. Elimination of defects allowed exploitation of the ultra-selective nature of polyamide TFCs, specifically for hydrogen and helium separations. At 23 °C, PIP-TMC, PPD-TMC and MPD-TMC exhibited H2/CH4 selectivities of 312, 362 and 1290, respectively, with moderate H2 permeances of 37.4, 32.6 and 25.8 GPU (1 GPU = 10−6 cm3(STP) cm−2 s−1 cmHg−1). Furthermore, the TFCs demonstrated excellent performance for H2/CO2 separation with pure-gas selectivities of 10–14 at 23 °C. The strong size-sieving capability of the polyamide TFCs originated from tight interchain packing induced by strong hydrogen bonding. Wide-angle X-ray diffraction confirmed a dominant fraction of submicropores of less than ~4 Å within PPD-TMC and PIP-TMC polyamide networks.

Heat and mass transfer characteristics and dehumidification performance improvement of an evaporatively-cooled liquid dehumidifier

In this paper, an evaporatively-cooled dehumidifier and its experimental test rig is introduced. By using the LiCl and CaCl2 solutions with mass concentration of 0.35 and 0.45 as liquid desiccants, the dehumidification performance improvement compared to adiabatic falling-film dehumidification and the heat and mass transfer characteristics of LiCl and CaCl2 solutions under evaporatively-cooled conditions are analyzed. The results indicate: the dehumidification rate under evaporatively-cooled condition is about 20% higher than that under adiabatic condition and the improving extent of dehumidification performance of the evaporatively-cooled dehumidifier appears more obviously under higher environmental temperature and humidity and lower solution concentration and higher solution temperature. Meanwhile, the dehumidification rate of LiCl is about 73% higher than that of CaCl2 under the same solution concentration, and the CaCl2 with mass concentration of 0.45 shows the parallel dehumidification performance with LiCl. As for the enthalpy effectiveness, CaCl2 with mass concentration of 0.35 is the highest. By changing the air, solution, and evaporative cooling air parameters, it is found that the heat and mass transfer coefficient is most significantly affected by air flow rate, and the heat transfer coefficient increases with the increase of solution flow rate but the mass transfer coefficient decreases. Moreover, four correlations on heat and mass transfer characteristics are given. In summary, the evaporatively-cooled devices can do effectively improve the solution dehumidification performance and the study results of this paper are beneficial to the industrial application of that device.

Decreased formation of disinfection by-products during electrochemical leachate oxidation and their post-removal by electro-adsorption

Membrane electrochemical reactor (MER) is an effective treatment system to remove recalcitrant compounds in landfill leachate but harmful byproducts can be formed during the treatment. Herein, we have investigated the formation of total halogenated organics and the associated toxicity as a side effect of leachate treatment by the MER. Those byproducts are represented by the term “disinfection byproducts, or DBPs”, because of the similar formation mechanisms. Several DBP groups were detected during the leachate treatment; however, the amount of DBP generated in the MER only accounted for 19.1 ± 4.5% of that in a membrane-less electrooxidation system (control). Likewise, the total toxicity value in the MER effluent was 26.6 × 10−3, only 15.1% of that in the control system. While trihalomethanes dominated mass concentration by 84.1% in the MER, haloacetonitriles contributed to majority of the additive toxicity due to their higher toxicity index. Increasing the initial leachate pH from 9.5 to 13 could increase the DBP concentration by 2.18 times because of less removal of humic acids. A high initial ammonia concentration of 6000 mg L−1 resulted in the increased DBP formation by 146.8%, compared to that with 2500 mg L−1, due to the increased formation of nitrogenous DBPs. A higher current density of 30 mA cm−2 doubled the DBP formation because of a faster reaction rate and a higher solution temperature. The extended treatment time caused trihalomethanes to continue forming DBP and degradation of most DBPs to some extent. With removing 67.5% of DBP mass concentration and 74.4% of the additive toxicity, the GAC-electrode system was shown more effective than GAC adsorption alone in remediating DBP from the MER effluent.

Influence of solution temperature on microstructure and mechanical properties of wrought Al-Si-Mg alloy

The microstructure and mechanical properties of wrought Al-12.7Si-0.7Mg alloy were investigated aiming at understanding the influence of the solution treatmen. The result show that the Si particles were gradually rounded and the grain size increase with increasing the solution temperature from 500°C to 540°C. The alloy in T4 condition changed due to the grain szie, Si particles and the super saturation level of Mg ans Si solute atoms. With higher solution temperature, the volume fraction of the pricipitate becomes more which result in good manchannical properties.

Reduction of bromate and chlorate contaminants in water using aqueous phase corona discharge

This work demonstrates the ability of aqueous phase corona discharge to chemically reduce bromate and chlorate ions, common disinfection byproducts, to bromide and chloride ions, respectively. A high voltage pulse was applied to a needle electrode, submerged in the target solution, to generate highly reactive oxidative and reductive species in a temperature-controlled reactor. Optimal water matrix conditions were sought through changing the solution pH, temperature, and dissolved oxygen concentration. Additionally, several oxidative species scavengers were investigated, including methanol, ethanol, sucrose, and D-sorbitol. Chemical reduction rates were improved at low pH (3.5). The presence of dissolved oxygen significantly reduced the chemical reduction rate, and thus high solution temperature (50 °C) also achieved better chemical reduction. All oxidative species scavengers improved the chemical reduction rate; however, methanol and ethanol were superior as these compounds generate hydrogen bubbles in the presence of plasma, which deoxygenates the solution further improving the chemical reduction rate. The application of this technology to 30 μM bromate and chlorate solutions, under optimal water matrix conditions and with the addition of 72 g/L-COD methanol, achieved greater than 95% removal of the target compounds within 60 min. Increasing the initial concentration of the target compounds to 300 μM required 90 and 150 min to achieve similar chemical reductions for bromate and chlorate, respectively.

Studies on the β → α Phase Transition Kinetics of Ti–3.5Al–5Mo–4V Alloy under Isothermal Conditions by X-ray Diffraction

The β → α phase transition kinetics of the Ti–3.5Al–5Mo–4V alloy with two different grain sizes was investigated at the isothermal temperature of 500 °C. A method to estimate the function of the precipitate fraction of the α phase with different aging times was developed based on X-ray diffraction analysis. The value of the α precipitate fraction increased sharply at first, then increased slowly with the aging time, and finally reached equilibrium. The value of the α precipitate fraction was higher in the alloy aged for the same time at a higher solution temperature, while the size of the α precipitate was smaller at a higher solution temperature. The β → α phase transition kinetics under isothermal conditions were modeled in the theoretical frame of the Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. The kinetic parameters of JMAK deduced different transformation mechanisms. The mechanism of the phase transition in the first stage was dominated by mixed transformation mechanisms (homogeneously nucleated and acicular-grown α structure, and grain boundary-nucleated and grown α precipitate), while the second stage was the growth of the fine α precipitate, which was controlled by slow diffusion. As the aging time increased, the hardness of the Ti–3.5Al–5Mo–4V alloy increased sharply. After the hardness of the alloy reached a plateau, it began to decline. The hardness of the alloy was always higher at a higher solution temperature.

Chemical Dissolution Drilling of Barre Granite Using a Sodium Hydroxide Enhanced Supercritical Water Jet

This experimental study focused on evaluating the technical feasibility of chemically enhancing rock comminution during supercritical hydrothermal jet drilling by increasing pH with additives. Comminution of the crystalline rock samples occurred under supercritical conditions at temperatures and pressures ranging from 535–580 °C and 22.5–27 MPa, respectively, using hydrothermal jets with sodium hydroxide concentrations ranging from 0.0725 to 0.345 mol/kg. Impinging hydrothermal jets induced thermal spallation and rock removal from 21 Barre granite specimens examined. These experimental conditions replicate those that would be encountered in drilling water-filled wells at depths greater than ~ 2300 m. The combination of accelerated mineral dissolution due to the presence of hydroxide ions, high solution temperature increasing reaction rates, and thermal stresses resulted in rates of rock removal up to 5.16 g in 10 min at 410 °C and 0.345 mol/kg NaOH. Comparison with published empirical quartz dissolution rates at high pH suggests granite mass removal primarily resulted from weakening of the rock matrix as a result of the accelerated dissolution of quartz minerals. Experimentally determined heat flux and surface temperature measurements indicated that the rock comminution occurred below the empirically determined minimum levels for the onset of continuous thermal spallation resulting from impinging low-density flame jets or high energy laser heating.

Mechanical behavior and deformation mechanism of 7075 aluminum alloy under solution induced dynamic strain aging

In this study the mechanical behavior and deformation mechanism of 7075 aluminum alloy sheets under dynamic strain aging induced by solution treatment were investigated. The uniaxial tensile tests were carried out at various strain rates (8.33 × 10−5 s−1, 1.67 × 10−3 s−1, 3.33 × 10−2 s−1 and 1.33 × 10−1 s−1) for samples treated by different solution processes (solution for 30 min at temperatures of 573 K, 623 K, 673 K and 748 K, and then quenching). The Portevin-Le Chatelier (PLC) effect (i.e., serration types of stress-strain curves, strain rate sensitivity (SRS) and critical strain) were analyzed, causing changes in tensile strength, work hardening rate and elongation. The morphology, sizes and quantities of precipitates under different solution-quenching conditions were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the dissolution of secondary phase occurs during heat treatment, accompanied by coarsening behavior at lower temperatures, which leads to the transition characteristics of mechanical properties of the aluminum alloy in solid solution state. There exists a critical point of solution temperature (623K), namely, when the solution temperature is lower than this critical point, the microstructure after quenching is mainly composed of the matrix and secondary phase; otherwise it is mainly composed of solid solution. Therefore, the samples heated at different solution temperatures have different types of PLC effects. It is worth noting that the strong effect of dynamic strain aging induced at high solution temperature and low strain rate could simultaneously enhance the strength and toughness.

Rejection of rare earth elements from a simulated acid mine drainage using forward osmosis: The role of membrane orientation, solution pH, and temperature variation

The high demand for the rare earth elements (REEs) in the clean technological industries implies the increased demand to produce these elements from ores and REEs containing impaired water sources such as acid mine drainage (AMD). However, the presence of these elements in AMD has increased their toxic exposure to the water environment. Herein, we investigated the role of the orientation of the membrane (such as active layer facing feed solution (AL-FS) or active layer facing draw solution (AL-DS) mode), solution pH, and temperature variation on the flux performance and rejection of three REEs (e.g., lanthanum, cerium, and dysprosium) from a simulated AMD solution using the forward osmosis (FO) process. It was found that there was a greater water flux at high pH, AL-DS mode of the FO system and high feed and draw solution temperature. FO could effectively reject all three REEs in both AL-FS and AL-DS membrane orientations mode due to steric hindrance. The rejection of these REEs in the AL-DS mode was slightly lower (82–88%) than that in the AL-FS mode (86–96%). The rejection of all REEs was noticeably influenced by solution pH in both mode. This was due to the changes in membrane surface with pH variation. The rejection of REEs increased when the temperature of the feed and draw solution was 20 and 40 °C, respectively. However, the rejection of all REEs decreased markedly when the temperature of the feed and draw solution was 40 and 20 °C, respectively. The lower rejection of these REEs was due to the enhancement of their diffusivity at a higher temperature in the feed side.

Influence of Nutrient Solution Temperature on Its Oxygen Level and Growth, Yield and Quality of Hydroponic Cucumber

High nutrient solution temperature stress around root-zone (rhizosphere) is a major factor limiting hydroponic crop growth due to change in dissolved oxygen (DO) levels in nutrient solution during the high-temperature seasons. This suggests that easier and economical control of root-zone temperature (RZT) could be an effective solution to the temperature stress for the crop plants in hydroponics. In this respect, the present investigation was undertaken to comprehend the influence of nutrient solution temperature on its oxygen level (ambient dissolved oxygen in feeding tank), growth, yield and quality of cucumber (Cucumis sativus L.) plants. The plants were cultivated in recirculating hydroponic system in a greenhouse with dimensions of 9 m wide &amp;times; 30 m long and total area of 270 m2 during three cropping periods in Oman viz. summer (June-August), fall (September-November) and spring (February-May) in two consecutive years 2016/2017 and 2017/2018. Three cooling treatments were applied viz. T1 (22 ᵒC), T2 (25 ᵒC) and T3 (28 ᵒC) through cooling nutrient solution besides non-cooled treatment T4 (33 ᵒC) as control. The plants were grown in pots filled with perlite medium in randomized complete design (RCD) with four replications. All the treatments received the same nutrient concentrations. The results showed that cooling of nutrient solution temperature influenced positively the levels of DO in the fresh nutrient solution feeding tank and drain nutrient solution for all cropping periods in both the years. Significant (p &amp;lt; 0.05) differences between the treatments were observed in oxygen consumption by the roots of cucumber in the cropping periods in both the years. High levels of oxygen consumptions were recorded with cooled RZTs as compared to that of control-non-cooled RZT for all cropping periods in both the years. All growth, production and quality attributes were positively influenced and greatly expressed by cooled root-zone temperature in the root-zone of cucumber with increased DO levels in nutrient solution. This study revealed that availability of optimum aeration (oxygen levels) in nutrient solution through cooling of nutrient solution temperature could be of significance for boosting cucumber yield as observed during all the growing periods especially in summer in Oman.

Cold sprayed WC reinforced maraging steel 300 composites: Microstructure characterization and mechanical properties

Maraging steel 300 (MS300) is a precipitation-strengthening iron–nickel alloy with outstanding properties such as good mechanical strength, weldability and corrosion resistance. However, the poor wear resistance has limited the application. In this work, high-performance WC reinforced MS300 composites were fabricated by high-pressure cold spray, which enables the additive manufacturing of bulk material well below its melting point. XRD analysis shows that no phase transformation occurred either to the WC reinforcements or the MS300 matrix. The distribution and morphology of the WC particles in the composite samples were characterized by X-ray computed tomography (XCT). The results show that a high retainability (85.4%) of WC particles was obtained at high working parameters (N2, 5 MPa, 900 °C), and the solution-aging treatment resulted in decreased WC volume fraction and smoothing of WC shape. Microstructure observation of WC evolution shows that a thick diffusion layer was formed around the WC particle after solution-aging treatment significantly improving the interfacial bonding. Due to the more severe plastic deformation and higher WC retainability, the as-fabricated samples with higher propelling gas pressure demonstrate a higher tensile strength and better wear resistance. It is found that a higher solution temperature (1000 °C) can lead to an enhanced cohesive bonding within the composite. Finally, the solution-aged composite shows an excellent wear resistance under the improved WC bonding and precipitation hardening.

Influence of temperature on high molecular weight poly(lactic acid) stereocomplex formation

The influence of temperature on the formation of high molecular weight poly(lactic acid) (PLA) stereocomplex was studied by evaluation of the precipitates from dioxane solutions of PLA enantiomers (PLLA and PDLA). The racemic mixtures were characterized by Gel Permeation Chromatography, Infrared Spectroscopy, Differential Scanning Calorimetry, Scanning Electronic Microscopy, Wide-Angle X-ray Scattering and Vicat Softening Temperature. Precipitation was carried out under different solution temperatures, keeping constant the mixing ratio (XD), the molecular weight, the optical purity of both PLA enantiomers and the stirring rate. It was found that the precipitates contained only pure stereocomplex crystallites (racemic crystallites), without observing crystal phase separation between both homocrystals. The kinetics of the insoluble phase formation could be adjusted with the Avrami model, classically used for polymer crystallization in molten state. It was observed that the maximum PLA stereocomplex production rate was at about 40°C. However, more thermally stable racemic crystallites were formed at high solution temperatures. It was found that all the precipitates were sphere-like at 10 g·dl–1 at the solution temperature of 25, 40, 60 and 80°C

A Study on Selectivity and Temperature Coefficients of the Chloride Ion Sensors With RuOx Thin Film

This paper investigated the response time, chloride selectivity, and temperature coefficients of the arrayed flexible ruthenium oxide chloride ion sensor in sodium chloride (NaCl) solutions with concentrations from 10−5 M to 1 M. The response time was 7 s in 1 M NaCl solution at room temperature, showing that the sensor had the characteristics of the fast response. The selectivity coefficients of the SO42− ion, NO3− ion, CO32− ion, ClO− ion, and ClO4− ion were 0.001, 0.056, 0.004, 0.015, and 0.006, respectively. The chloride ion sensing device had the good chloride selectivity. Finally, the sensitivity was investigated with different solution temperatures from 5 °C to 50 °C. The sensitivity was increased with higher solution temperature. The temperature coefficient of the sensitivity of the chloride ion sensing device was approximately 0.681 mV/pCl °C between 5 °C and 35 °C.

Backbone-free duplex-stacked monomer nucleic acids exhibiting Watson–Crick selectivity

We demonstrate that nucleic acid (NA) mononucleotide triphosphates (dNTPs and rNTPs), at sufficiently high concentration and low temperature in aqueous solution, can exhibit a phase transition in which chromonic columnar liquid crystal ordering spontaneously appears. Remarkably, this polymer-free state exhibits, in a self-assembly of NA monomers, the key structural elements of biological nucleic acids, including: long-ranged duplex stacking of base pairs, complementarity-dependent partitioning of molecules, and Watson-Crick selectivity, such that, among all solutions of adenosine, cytosine, guanine, and thymine NTPs and their binary mixtures, duplex columnar ordering is most stable in the A-T and C-G combinations.

Solution Treatment Process of Haynes 230 Cylindrical Blank Used for Hot Flow Spinning

Hot flow spinning is one of the most effective methods to manufacture the cylindrical parts of nickel-based superalloy. However, crack occurs easily in the hot flow spinning process of Haynes230 alloy when the cylindrical blanks are obtained by forging and wire-electrode cutting billet due to the severe segregation of carbides existed in the microstructure of the Haynes230 forging billet. The solution treatment process of Haynes230 blank is put forward to obtain the cylindrical blank with homogeneous and fine grained microstructure used for hot flow spinning. The influence of solution treatment process on the microstructure and hardness of Haynes 230 was investigated; and the relationship between grain size and solution temperature was analyzed. The results show that the grain size of Haynes230 alloy increases with the increasing of solution temperature and the holding time. The abnormal growth of grains occurs under excessively high solution temperature and long holding time. The grain growth activation energy of Haynes230 is about 296.0kJ/mol. The hardness of Haynes230 alloy decreases with the increasing of solution temperature, but negligibly changes with the holding time. The severe segregation of carbides can be eliminated and the cylindrical blank with homogeneous and fine grained microstructure used for hot flow spinning of Haynes230 alloy can be obtained after solution treatment at 1230°C for 60 min heat preservation.