Hot Component Research Articles

Hot corrosion damage mechanism of Ti6Al4V alloy in marine environment

This study investigated the corrosion behaviors of Ti6Al4V alloy during the hot salt and hot salt - water vapor tests. Ti6Al4V suffered from slight oxygen erosion at the initial stage, while chlorine greatly accelerated the oxide growth. The initial and accelerated oxidation reactions resulted in a continuous mass gain of Ti6Al4V during the hot salt test. Ti6Al4V experienced severe corrosion degradation during the hot salt - water vapor test. The reaction between oxides, chloride salt and water induced the formation of hydrochloric acid (HCl), while chlorine reacted with water to form HCl. The HCl subsequently reacted with the alloy to form gaseous chlorides, that volatilized to the outside and consequently led to a significant mass loss of Ti6Al4V. These results confirmed that the oxidation - hot salt - water vapor synergism effect showed a strong damage on the hot end components of titanium alloy during the marine service.

Measurements of radial profile of isotope density ratio using bulk charge exchange spectroscopy.

A bulk charge exchange spectroscopy (BCXS) system using a grism (grating prism) spectrometer has been applied to measure the profile of the deuterium (D) fraction in deuterium and hydrogen (H) mixture plasma in the Large Helical Device. The observed spectrum can be fitted with four Gaussian functions successfully by reduction of free parameters for the least-squares fit. The plasma flow velocity and ion temperature profile measured by charge exchange spectroscopy using carbon impurity are used for estimation of the wavelength shift of hot components to reduce the free parameter. The ion temperature is used to estimate the apparent wavelength shift due to the energy dependent emission cross section only and is not used to set the Doppler width for H and D in the fitting. The sensitivity of the evaluated D fraction on the velocity is increased for a higher D fraction. The error of the D fraction is calculated from the error in the fitted parameter and sensitivity on the velocity of the hot component. The difference in the profile and time trace of the D fraction with D pellet and H pellet injection was observed clearly by BCXS using a grism spectrometer.

Influence of oxide thickness on thermal behaviour of high temperature coatings

Durability of hot components in Gas Turbine engines largely depends on a constantly evolving oxide layer thickness that changes with time and temperature. During the flight cycle, high temperature coated components continuously develop oxide layers that affect thermal and stress fields which dictate component life. Thus, it becomes vital to comprehensively model this oxide growth. In the present article, an experimentally validated thermal model is developed for a combustor tile using a Rolls Royce in house Finite Element code. This model is used to perform 1000 real flight cycle analysis using a Python automated workflow. Each flight cycle analysis is done in such a way that dynamic variation in oxide thickness is accounted implicitly by factoring material properties. Results confirmed that, oxide growth is random and conventional analysis under-predicted oxide thickness by 40%. Due to this the thermal insulation capability of the system is constantly changing. Equivalent thermal resistance on a critical volume varied non-uniformly from 47% to 11%. This change redefined temperature distribution and there-by stress fields resulting in an under prediction of component life by 28%. Thus, through this paper a comprehensive analysis workflow is proposed and developed that improves the life prediction of combustor tiles.

Impingement/effusion cooling with a hollow cylinder structure for additive manufacturing: Effect of channel gap height

The present study is to investigate the effect of gap height on heat/mass transfer for impingement/effusion cooling of gas turbine hot components, using a hollow cylinder structure created by three perforated plates with two channels. The detailed local heat/mass transfer coefficients on all surfaces of the structure are measured in the test section using a naphthalene sublimation method. Flow characteristics in the structure are revealed using a numerical simulation such as jet impingement, wall jets, and toroidal vortices. The hole spacing (P/D) and thickness of plate (t/D) in the present study are 6 and 1, respectively. The various gap height ratios, which mean the ratios between the gap height of the first channel and that of the second channel, are 1:4 (0.2D-0.8D), 1:1 (0.5D-0.5D), and 4:1 (0.8D-0.2D). Depending on the gap height ratios, heat/mass transfer distributions are obtained differently on each surface of the structure. The area-averaged Sherwood number on each surface shows a large variation ranging from 27% reduction in UM of the Case 3 and 42% increase in UB of the Case 3 with different gap heights at the Reynolds number (ReD) of 7,000. Considering the benefits of heat/mass transfer augmentation and the drawbacks associated with an increase in pressure drop, the structural configuration of the first channel of low gap height and the second channel of high gap height has the highest thermal performance factor, with an improvement of 4.8% at ReD = 7,000. The scale of gap height and wall thickness of the gas turbine hot components should be selected in terms of the total blade wall thickness, number of multi-layers, and manufacturing tolerance in additive manufacturing. Therefore, as gap height for the channel in the laminated structure is limited, the case of the gap height ratios of 1:4, which is the low gap height for the first channel and the high gap height for the second channel, offers the best cooling performance for gas turbine components compared to its counterpart having a high gap height of the first channel and a low gap height of the second channel.

Self-healing capacity of Mullite-Yb2SiO5 environmental barrier coating material with embedded Ti2AlC MAX phase particles

Repetitive heating and cooling cycles inevitably cause crack damage of hot gas components of gas turbine engines, such as blades and vanes. In this study the self-healing capacity is investigated of mullite + ytterbium monosilicate (Yb2SiO5) as EBC material with Ti2AlC MAX phase particles embedded as a crack-healing agent. The effect of Ti2AlC in the EBC was compared with the self-healing ability of the mullite + Yb2SiO5 material. After introducing cracks by Vickers indentation on the surface of each sample, crack healing was realized by controlling the temperature and time during the post-heat-treatment process. For the mullite + Yb2SiO5 composite with Ti2AlC particles, crack healing occurred at 1000 °C, while in the case of the mullite + Yb2SiO5 composite without Ti2AlC, a sustained temperature of 1300 °C or higher was required. Compared with the healing of the mullite + Yb2SiO5 composite by the formation of a eutectic phase, the addition of Ti2AlC promoted healing via the oxidation of Ti and Al. Notably, the surface formation of a ternary oxide of Ti–Yb–O was confirmed, which completely covered the damage area. Consequently, the addition of a Ti2AlC MAX phase to the EBC composite resulted in a complete strength recovery, while the mullite + Yb2SiO5 composite without Ti2AlC showed a strength recovery of about 80%. Furthermore, by analyzing the indentation load–displacement curve to indicate the role of Ti2AlC, the addition of Ti2AlC improved both the hardness and stiffness of the composite.

Thermal instability in the CGM of L⋆ galaxies: testing ‘precipitation’ models with the FIRE simulations

ABSTRACT We examine the thermodynamic state and cooling of the low-z circumgalactic medium (CGM) in five FIRE-2 galaxy formation simulations of Milky Way-mass galaxies. We find that the CGM in these simulations is generally multiphase and dynamic, with a wide spectrum of largely non-linear density perturbations sourced by the accretion of gas from the intergalactic medium (IGM) and outflows from both the central and satellite galaxies. We investigate the origin of the multiphase structure of the CGM with a particle-tracking analysis and find that most of the low-entropy gas has cooled from the hot halo as a result of thermal instability triggered by these perturbations. The ratio of cooling to free-fall time-scales tcool/tff in the hot component of the CGM spans a wide range of ∼1−100 at a given radius but exhibits approximately constant median values of ∼5−20 at all radii 0.1Rvir < r < Rvir. These are similar to the ≈10−20 value typically adopted as the thermal instability threshold in ‘precipitation’ models of the ICM. Consequently, a one-dimensional model based on the assumption of a constant tcool/tff and hydrostatic equilibrium approximately reproduces the number density and entropy profiles of each simulation but only if it assumes the metallicity profile and temperature boundary condition taken directly from the simulation. We explicitly show that the tcool/tff value of a gas parcel in the hot component of the CGM does not predict its probability of subsequently accreting on to the central galaxy. This suggests that the value of tcool/tff is a poor predictor of thermal stability in gaseous haloes in which large-amplitude density perturbations are prevalent.

Viscoplastic constitutive modeling of boron steel under large strain conditions and its application in hot semi-cutting

Abstract To overcome the long process time of laser cutting and the high costs for repairing cold blanking tools of ultra-high strength hot stamping components, the hot semi-cutting process was proposed. The reliable testing and parameter identification method of the constitutive behavior under large strain conditions are essential for an accurate simulation of hot stamping and hot semi-cutting process. In the present work, a new testing and parameter identification method for the viscoplastic constitutive behavior of boron steel is proposed based on the Gleeble system, which includes a new grip design, shear specimen selection, and its relevant high-temperature and high-speed digital image correlation (DIC) technology. To obtain the stress-strain curves under large deformation, the FEM-based optimization method is also proposed to identify the hardening parameters. To cover a greater strain range, a new viscoplastic hardening model is proposed based on the dislocation density evolution under elevated temperature deformation conditions. The reliability of the proposed testing method and hardening model is verified by the analysis of uniformity of temperature and strain rate, and the comparison of predicted stress-strain curves with parameters identified from shear and tensile testing. The thermomechanical tension of the center-hole and notched specimen, and the hot semi-cutting process are carried out to verify the proposed testing method and hardening model. The results show that the shear specimen has a more uniform temperature and strain rate distribution in the deformation zone than the tensile specimen. Shear specimens can be used to test the hardening behavior under various process conditions until failure at the large strain. The insensitivity to phase transformations of shear testing is another advantage for identifying the constitutive behavior of the product phase formed during continuous cooling. The constitutive behavior of the boron steel under a large strain range can be accurately identified by using the FEM-based optimization method proposed in this paper. Besides, the mechanical response of the center-hole specimen, notched specimen, and the hot semi-cutting deformation predicted by the proposed hardening model shows accurate results.

Nitrogen X-ray absorption in the local ISM

ABSTRACT Nitrogen is one of the most abundant metals in the interstellar medium (ISM), and thus it constitutes an excellent test to study a variety of astrophysical environments, ranging from nova to active galactic nuclei. We present a detailed analysis of the gaseous component of the N K-edge using high-resolution XMM–Newton spectra of 12 Galactic and 40 extragalactic sources. For each source, we have estimated column densities for N i, N ii, N iii, N v, N vi, and N vii ionic species, which trace the cold, warm, and hot phases of the local Galactic ISM. We have found that the cold-warm component column densities decrease with the Galactic latitude, while the hot component does not. Moreover, the cold column density distribution is in good agreement with UV measurements. This is the first detailed analysis of the nitrogen K-edge absorption due to ISM using high-resolution X-ray spectra.

RANCANG BANGUN SAFETY DEVICE COOLING DOWN AUTOMATIC PADA UNIT HEAVY EQUIPMENT DOZER D3K CATERPILLAR BERBASIS MICROCONTROLLER

The occurrence of problems regarding operating procedures that are not suitable for heavy equipment in the field is one of the causes of component life which is not maximally achieved. Therefore it is necessary to have an innovation to make it easier to monitor and operate heavy equipment, especially when there is a shift in work shift for heavy equipment operators. Operator experience in several mining activities, many operators shut down the engine suddenly so that the impact on the engine can cause over heating which results in excessive wear and will have an impact on engine performance. And therefore the purpose of design a microcontroller-based cooling down safety device is a tool that functions to turn off the engine when the engine is low idle with time settings according to the standard operating procedure of each machine. For machines that have been operated under load, the engine must be low idle / cooling down for a while, so that the heat on the engine surface is cool enough, so that hot components can be properly lubricated. By design a cooling down engine safety device, it is hoped that it can assist in the monitoring and operation of heavy equipment. From the results of field testing, the relay that controls the unit's electricity functions properly and the cooling down safety device has a precise timing.

TGO growth and kinetic study of single and double layered TBC systems

Thermal barrier coating (TBC) systems are widely used to prolong the lifetime of hot section components in gas turbines. Oxidation degradation at high temperature is inevitable despite the use of TBC systems. In the current study, Yttria stabilized zirconia (YSZ)/CoNiCrAlY/Inconel 718 and La2Zr2O7 (LZO)/YSZ/CoNiCrAlY/Inconel 718 TBC systems were produced and exposed to high temperature oxidation tests. After the tests, a thermally grown oxide (TGO) layer formed at the interface between the bond and top coating due to the oxidation of bond coating. This layer has a critical importance for the lifetime of TBCs. The oxidation kinetics, rate constants, and activation energy values of both TBC systems were calculated using TGO thickness values. At the end of the oxidation tests, the double-layered LZO/YSZ TBC system exhibited better performance thanks to the lower oxygen permeability of LZO considering oxidation kinetics results and microstructural investigations. However, the formed TGO layer consisting of alumina and mixed oxides (MOs) led to crack formation at the interface. Besides, higher temperatures and increasing oxidation periods also degraded the integrity of top coatings due to the sintering effect. Chemical incompatibility did not affect the interface durability of the LZO/YSZ TBC system during the oxidation tests.

Multiwavelength analysis of the X-ray spur and southeast of the Large Magellanic Cloud

Aims. The giant H II region 30 Doradus (30 Dor) located in the eastern part of the Large Magellanic Cloud is one of the most active star-forming regions in the Local Group. Studies of H I data have revealed two large gas structures which must have collided with each other in the region around 30 Dor. In X-rays there is extended emission (~1 kpc) south of 30 Dor called the X-ray spur, which appears to be anticorrelated with the H I gas. We study the properties of the hot interstellar medium (ISM) in the X-ray spur and investigate its origin including related interactions in the ISM. Methods. We analyzed new and archival XMM-Newton data of the X-ray spur and its surroundings to determine the properties of the hot diffuse plasma. We created detailed plasma property maps by utilizing the Voronoi tessellation algorithm. We also studied H I and CO data, as well as optical line emission data of Hα and [S II], and compared them to the results of the X-ray spectral analysis. Results. We find evidence of two hot plasma components with temperatures of kT1 ~ 0.2 keV and kT2 ~ 0.5−0.9 keV, with the hotter component being much more pronounced near 30 Dor and the X-ray spur. In 30 Dor, the plasma has most likely been heated by massive stellar winds and supernova remnants. In the X-ray spur, we find no evidence of heating by stars. Instead, the X-ray spur must have been compressed and heated by the collision of the H I gas.

An analytical model for predicting residual stress in TBC-film cooling system considering non-uniform temperature field

Residual stress is an important parameter to evaluate and predict the interfacial peeling and failure of a thermal barrier coating (TBC) system in the thermal cycle. Considering a non-uniform temperature field, an analytical model for predicting residual stress of the TBC-film cooling system was established. Based on the double-layer TBC-film cooling system, the analytical solutions were validated by comparing with the previous results. Then, the four-layer system, including the superalloy substrate (SUB), the metallic bond coat (BC), the thermally grown oxide (TGO), and the ceramic top coat (TC), was analyzed. The distribution of residual stress was discontinuous at the interface among the layers. The maximum peeling moment occurred at the BC/SUB interface, and the maximum shear stress occurred at the TGO/BC interface. Therefore, the probabilities, of which opening edge cracks (mode I) appeared at the BC/SUB interface and shearing edge cracks (mode II) appeared at the TGO/BC interface, were higher than that at other interfaces. The deflection and bending direction of the system were affected by the temperature difference and coefficient of thermal expansions. The large thickness of the coating could effectively improve the thermal insulation capacity of the system, but the peeling moment and shear stress also increased. Therefore, preventing the thermal growth of the TGO layer and reducing the thickness of the TC layer can improve the stability of the system and extend service lifetime of the system while ensuring that the cooling requirements for hot section components are met.

Shaping quality, microstructure, and mechanical properties of melt-grown mullite ceramics by directed laser deposition

Directed laser deposition (DLD) has demonstrated the potential for rapid preparing high-performance melt-grown ceramics applied for the aero-engine hot section components. Mullite has excellent potential for applications in harsh environments and extreme conditions. However, there are defects (pores and cracks) in melt-grown mullite ceramics (MGMC), limiting its application, related to unclear processes, microstructure, and properties. In this work, we investigated the impact of z-increment on shaping quality, microstructure, and mechanical properties. The results reveal that oxygen vacancy concentration is responsible for the variety of sample colors. Low z-increment is beneficial to decreasing porosity, while high z-increment is beneficial to crack suppression. The formation and propagation mechanism of internal cracks at low z-increment are discussed in detail. Mullite crystals in the sample center are "tabular cellular", which are 2:1 high-alumina mullite. While mullite crystals at the sample edge are 3:2 mullite, undergo four stages as z-increment increase; "tabular cellular", "facet dendrite", "rod cellular", and mixed crystal. This evolution of crystal morphology is attributed to the decrease in temperature gradient and the increase of supersaturation. Besides, the flexural strength and microhardness increase first and then decrease with the rise of z-increment, which is the function of defects, compactness, and microstructure.

Reliability analysis of heat exchanging system of deep-sea manned submersibles using Markov model

This study introduces reliability assessment models for heat exchanging systems in deep-sea manned submersibles based on the Markov analysis method. Three distinct design systems—a series solution and two series–parallel solutions, considering cold and hot standby components—were presented. In addition, the state transition models of the Markov random process were established with relation to common-cause failures. Moreover, the calculation methods were derived for the two reliability indices of the heat exchange system: steady state availability and mean time to failure. Thus, the reliability of various design solution cases was investigated by comparing the reliability indices with variations in the failure and repair rates. The influence of common-cause factors on the system reliability was discussed as well. Furthermore, design solutions were suggested based on the results of the quantitative calculations and analysis.

The HOSTS Survey: Evidence for an Extended Dust Disk and Constraints on the Presence of Giant Planets in the Habitable Zone of β Leo

Abstract The young (50–400 Myr) A3V star β Leo is a primary target to study the formation history and evolution of extrasolar planetary systems as one of the few stars with known hot (∼1600 K), warm (∼600 K), and cold (∼120 K) dust belt components. In this paper, we present deep mid-infrared measurements of the warm dust brightness obtained with the Large Binocular Telescope Interferometer (LBTI) as part of its exozodiacal dust survey (HOSTS). The measured excess is 0.47% ± 0.050% within the central 1.5 au, rising to 0.81% ± 0.026% within 4.5 au, outside the habitable zone of β Leo. This dust level is 50 ± 10 times greater than in the solar system’s zodiacal cloud. Poynting–Robertson drag on the cold dust detected by Spitzer, and Herschel underpredicts the dust present in the habitable zone of β Leo, suggesting an additional delivery mechanism (e.g., comets) or an additional belt at ∼5.5 au. A model of these dust components is provided that implies the absence of planets more than a few Saturn masses between ∼5 au and the outer belt at ∼40 au. We also observationally constrain giant planets with the LBTI imaging channel at 3.8 μm wavelength. Assuming an age of 50 Myr, any planet in the system between approximately 5–50 au must be less than a few Jupiter masses, consistent with our dust model. Taken together, these observations showcase the deep contrasts and detection capabilities attainable by the LBTI for both warm exozodiacal dust and giant exoplanets in or near the habitable zone of nearby stars.

Early fault detection of gas turbine hot components under different ambient and operating conditions

Failure of hot components in gas turbines often causes catastrophic results. Early fault detection can prevent serious incidents and improve the availability. A novel early fault detection method of hot components is proposed in this article. Exhaust gas temperature is usually used as the indicator to detect the fault in the hot components, which is measured by several exhaust thermocouples with uniform distribution at the turbine exhaust section. The healthy hot components cause uniform exhaust gas temperature (EGT) profile, whereas the hot component faults could cause the uneven EGT profile. However, the temperature differences between different thermocouple readings are also affected by different ambient and operating conditions, and it sometimes has a greater influence on EGT than the faults. In this article, an accurate EGT model is presented to eliminate the influence of different ambient and operating conditions on EGT. Especially, the EGT profile swirl under different ambient and operating conditions is also included by considering the information of the thermocouples’ spatial correlations and the EGT profile swirl angle. Based on the developed EGT model, the detection performance of early fault detection of hot components in gas turbine is improved. The accuracy and effectiveness of the developed early fault detection method are evaluated by the real-world gas turbine data.

Degradation characteristics of thermal barrier coatings for hot corrosion and CaO–MgO–Al2O3–SiO2

Hot corrosion and CaO–MgO–Al 2 O 3 –SiO 2 (CMAS) resistance of thermal barrier coatings (TBCs) are required in an industrial gas turbine employed with impure fuels and high turbine inlet temperatures . Therefore, various TBC systems with different structural combinations were investigated in thermochemical aspects of hot corrosion and CMAS causing the degradation of TBCs. Four types of 8 wt% yttria-stabilized zirconia (8YSZ), namely dense microstructure (8YSZ), porous microstructure (C–8YSZ), no monoclinic phase (NoM–8YSZ), and low thermal conductivity (low-k), were employed to prepare topcoats using an atmospheric plasma spray on the two bondcoats coated by a vacuum plasma spray with feedstocks of NiCoCrAlY and NiCoCrAlY+Hf + Si. Hot corrosion components penetrated through the whole topcoat layer at 1000 °C however did not infiltrate to the bondcoat layers because of the thermally grown oxide layer formed between the topcoat and the bondcoat. In addition, the elements Hf and Si contained in the bondcoat composition suppressed diffusion of β phase aluminum. In the visual inspection after the hot corrosion at 1000 °C and CMAS test at 1250 °C, the TBC system with the NoM–YSZ topcoat layer showed a sound condition without failure unlike other TBCs, and no monoclinic phase after hot corrosion and the CMAS test, indicating that the phase stability plays a critical role in TBCs' lifetime in the hot corrosion and CMAS environments. • Superiority of Hf and Si elements in MCrAlY bondcoat was observed through hot corrosion test. • Conventional and advanced TBCs failed with a similar trend independent of chemicals and porosity. • low-k TBCs showed a negative dependency on both hot corrosion and CMAS • Phase stability of topcoat layer can also be proposed to have more life time under the environment of hot corrosion and CMAS.

Measurement Drift in 3-Hole Yaw Pressure Probes From 5µm Sand Fouling at 1050 °C

AbstractThe present paper focuses on the resilience of 3-hole pressure probes to hot sand fouling in turbomachinery environments. These probes are utilized inside jet engine hot sections for diagnostics and flow characterization. Ingestion of sand and other particulates pose a significant risk to hot section components and measurement devices in gas turbine engines. In this study, wedge, cylindrical, and trapezoidal probes were exposed to hot section turbine aerothermal conditions of 1050 °C and 65–70 m/s flow velocity and fouled with 0–5 µm Arizona Road Dust (ARD). Sand accumulated more rapidly on the surface of the trapezoidal and cylindrical probe geometries than on the surface of the wedge probe geometry. Probe calibrations following sand fouling were performed in an ambient temperature, open air, calibration jet at Mach 0.3 and 0.5. Calibration curves using nondimensional coefficients were used to assess probe error in yaw angle due to sand fouling. Probe error was based on each probe’s ability to accurately measure flow direction over a flow angle range of [−10 deg, 10 deg]. On average, the probes displayed greater error at Mach 0.5 than Mach 0.3. The wedge probe performed the best after sand fouling and displayed a maximum error of less than ±2 deg in yaw angle. In contrast, the cylindrical probe performed the worst after sand fouling and displayed maximum errors of more than ±8 deg in yaw angle. Transient response did not change notably with sand fouling.

Supervirial Temperature or Neon Overabundance? Suzaku Observations of the Milky Way Circumgalactic Medium

Abstract We analyzed Suzaku and Chandra observations of the soft diffuse X-ray background toward four sight lines with the goal of characterizing the X-ray emission from the Milky Way circumgalactic medium (CGM). We identified two thermal components of the CGM, one at a uniform temperature of kT = 0.176 ± 0.008 keV and the other at temperatures in the range kT = 0.65–0.90 keV. The uniform lower-temperature component is consistent with the Galaxy’s virial temperature (∼106 K). The temperatures of the hotter components are similar to that recently discovered (∼107 K) in the sight line to blazar 1ES 1553+113, passing close to the Fermi bubble. Alternatively, the spectra can be described by just one lower-temperature component with supersolar neon abundance, once again similar to that found in the 1ES 1553+113 sight line. The additional hot component or the overabundance of Ne is required at a significance of >4σ, but we cannot distinguish between the two possibilities. These results show that the supervirial temperature gas or an enhanced Ne abundance in the warm-hot gas in the CGM is widespread, and these are not necessarily related to the Fermi bubble.

Eight-year Simultaneous Monitoring Observations of H2O and SiO Masers toward V627 Cas

Abstract Simultaneous monitoring observations of H2O 61,6 − 52,3 and SiO v = 1, 2, J = 1 → 0, v = 1, J = 2 → 1, J = 3 → 2 masers were performed toward the suspected D-type symbiotic star V627 Cas from 2011 October to 2020 March using the Korean Very Long Baseline Interferometry (VLBI) Network (KVN) single-dish telescopes. All spectra of the H2O masers showed highly redshifted emissions with respect to the stellar velocity of −52 km s−1 with high asymmetries. In addition, the spectra of the H2O maser showed three components which varied according to observational dates. On the other hand, the SiO v = 1, 2, J = 1 → 0 and v = 1, J = 2 → 1 masers exhibited a predominantly blueshifted emission in most epochs. The SiO v = 1, J = 3 → 2 maser has arisen around the stellar velocity from 2016 November 19 and shows a predominantly redshifted emission from 2018 June 15. We analyze time variations of the H2O and SiO maser intensities, their intensity ratios, peak and mean velocities, and full width zero power. Based on these analyses, the asymmetries of the H2O and SiO masers’ spectra in V627 Cas and the variation characteristics of the maser properties of the different maser lines are discussed. As a possible cause of asymmetries, the influence of a hot component located at the eastern part of the red giant can be suggested based on the KVN VLBI results. The differences in the variation characteristics of the maser properties may originate from the differences in their locations and excitation conditions.