High-Temperature Erosion Resistance of Coatings for Gas Turbine

1992 ◽  
Vol 114 (2) ◽  
pp. 242-249 ◽  
Author(s):  
W. Tabakoff ◽  
A. Hamed ◽  
M. Metwally ◽  
M. Pasin
Keyword(s):  
High Temperature ◽  
Protective Coatings ◽  
Coal Ash ◽  
Mass Effect ◽  
Impact Angle ◽  
Unit Weight ◽  
Weight Losses ◽  
Aluminide Coatings ◽  
Particle Flows ◽  
The Impact

An experimental investigation was conducted to study the ash particle rebound characteristics and the associated erosion behavior of superalloys and aluminide coatings subjected to gas-particle flows at elevated temperature. A three-component LDV system was used to measure the restitution parameters of 15 micron mean diameter coal-ash particles impacting some widely used superalloys and coatings at different angles. The presented results show the variation of the particle restitution ratios with the impingement angle for the coated and uncoated superalloys. The erosion behaviors of INCO-738, MAR 246 and X40 superalloys and protective coatings C, N, RT22 and RT22B also have been investigated experimentally at high temperature using a specially designed erosion tunnel. The erosion results show the effect of velocity, temperature and the impact angle on the erosion rate (weight loss per unit weight of particles). Based on the experimental results of the particle mass effect on both weight losses and erosion rates, the coating lives have been estimated for different particle concentrations.

scholarly journals High Temperature Erosion Resistance of Coatings for Gas Turbine

1991 ◽  
Author(s):  
W. Tabakoff ◽  
A. Hamed ◽  
M. Metwally ◽  
M. Pasin
Keyword(s):  
Elevated Temperatures ◽  
Protective Coatings ◽  
Coal Ash ◽  
Mass Effect ◽  
Impact Angle ◽  
Unit Weight ◽  
Weight Losses ◽  
Aluminide Coatings ◽  
Particle Flows ◽  
The Impact

An experimental investigation was conducted to study the ash particle rebound characteristics and the associated erosion behavior of superalloys and aluminide coatings subjected to gas-particle flows at elevated temperatures. A three-component LDV system was used to measure the restitution parameters of 15 micron mean diameter coal ash particles impacting some widely used superalloys and coatings at different angles. The presented results show the variation of the particle restitution ratios with the impingement angle for the coated and uncoated superalloys. The erosion behaviors of INCO-738, MAR 246 and X40 superalloys and protective coatings C, N, RT22 and RT22B have also been investigated experimentally at high temperatures using a specially designed erosion tunnel. The erosion results show the effect of velocity, temperature and the impact angle on the erosion rate (weight loss per unit weight of particles). Based on the experimental results of the particle mass effect on both weight losses and erosion rates, the coating lives have been estimated for different particle concentrations.

scholarly journals High Temperature Coatings for Protection Against Turbine Deterioration

1993 ◽  
Author(s):  
W. Tabakoff ◽  
M. Metwally ◽  
A. Hamed
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
High Temperatures ◽  
Erosion Rate ◽  
Wind Erosion ◽  
Protective Coatings ◽  
Impact Angle ◽  
Steam Turbines ◽  
Erosion Behavior ◽  
The Impact

In this research, an investigation was conducted to study the fly ash particles associated with the erosion behavior of alloys and coatings which are widely used in gas and steam turbines. The erosion behavior of many alloys and protective coatings has been investigated experimentally at high temperatures using a specially designed wind erosion tunnel. The erosion results show the effect of velocity, temperature and the impact angle on the erosion rate.

High-Temperature Coatings for Protection Against Turbine Deterioration

1995 ◽  
Vol 117 (1) ◽  
pp. 146-151 ◽  
Author(s):  
W. Tabakoff ◽  
M. Metwally ◽  
A. Hamed
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
High Temperatures ◽  
Erosion Rate ◽  
Wind Erosion ◽  
Protective Coatings ◽  
Impact Angle ◽  
Steam Turbines ◽  
Erosion Behavior

In this research, an investigation was conducted to study the fly ash particles associated with the erosion behavior of alloys and coatings that are widely used in gas and steam turbines. The erosion behavior of many alloys and protective coatings has been investigated experimentally at high temperatures using a specially designed wind erosion tunnel. The erosion results show the effect of velocity, temperature, and impact angle on the erosion rate.

Coating Effect on Particle Trajectories and Turbine Blade Erosion

1992 ◽  
Vol 114 (2) ◽  
pp. 250-257 ◽  
Author(s):  
W. Tabakoff ◽  
M. Metwally
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Protective Coatings ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Axial Flow ◽  
Coal Ash ◽  
Impact Angle ◽  
Laser Doppler Velocimeter ◽  
Particle Trajectories

Gas turbine engines operating in dusty environments are exposed to erosion and performance deterioration. In order to improve the erosion resistance, nickel and cobalt superalloy blades and vanes are widely used in the hot section of gas turbines. Protective coatings have been used to enhance superalloy resistance to hot erosion. An investigation has been conducted to study coal ash particle dynamics and resulting blade erosion for both uncoated and coated blades of a two-stage axial flow gas turbine. A quasi-three-dimensional flow solution is obtained for each blade row for accurate computation of particle trajectories. The change in particle momentum due to collision with the turbine blades and casings is modeled using restitution parameters derived from three-component laser-Doppler velocimeter measurements. The erosion models for both blade superalloy and coatings are derived based on the erosion data obtained by testing the blade superalloy and coatings in a high-temperature erosion wind tunnel. The results show both the three-dimensional particle trajectories and the resulting blade impact locations for both uncoated and coated blade surfaces. In addition are shown the distribution of the erosion rate, impact frequency, impact velocity, and impact angle for the superalloy and the coating. The results indicate significant effects of the coating, especially on blade erosion and material deterioration.

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

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

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

scholarly journals Temperature, Disease, and Death in London: Analyzing Weekly Data for the Century from 1866 to 1965

2021 ◽  
pp. 1-41
Author(s):  
W. Walker Hanlon ◽  
Casper Worm Hansen ◽  
Jake Kantor
Keyword(s):  
Nineteenth Century ◽  
High Temperature ◽  
Mortality Data ◽  
Late Nineteenth Century ◽  
Infant Deaths ◽  
Digestive Diseases ◽  
Late Nineteenth ◽  
The Impact ◽  
The City

Using novel weekly mortality data for London spanning 1866-1965, we analyze the changing relationship between temperature and mortality as the city developed. Our main results show that warm weeks led to elevated mortality in the late nineteenth century, mainly due to infant deaths from digestive diseases. However, this pattern largely disappeared after WWI as infant digestive diseases became less prevalent. The resulting change in the temperature-mortality relationship meant that thousands of heat-related deaths—equal to 0.9-1.4 percent of all deaths— were averted. These findings show that improving the disease environment can dramatically alter the impact of high temperature on mortality.

scholarly journals The modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rui Zhang ◽  
Yujie Meng ◽  
Hejia Song ◽  
Ran Niu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
High Temperature ◽  
Air Pollutants ◽  
Meteorological Data ◽  
Effect Of Temperature ◽  
Distributed Lag ◽  
Modification Effect ◽  
Incidence Risk ◽  
The Impact ◽  
The Relationship

Abstract Background Although exposure to air pollution has been linked to many health issues, few studies have quantified the modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China. Methods The data of daily incidence of influenza and the relevant meteorological data and air pollution data in Ningbo from 2014 to 2017 were retrieved. Low, medium and high temperature layers were stratified by the daily mean temperature with 25th and 75th percentiles. The potential modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo was investigated through analyzing the effects of air pollutants stratified by temperature stratum using distributed lag non-linear model (DLNM). Stratified analysis by sex and age were also conducted. Results Overall, a 10 μg/m3 increment of O3, PM2.5, PM10 and NO2 could increase the incidence risk of influenza with the cumulative relative risk of 1.028 (95% CI 1.007, 1.050), 1.061 (95% CI 1.004, 1.122), 1.043 (95% CI 1.003, 1.085), and 1.118 (95% CI 1.028, 1.216), respectively. Male and aged 7–17 years were more sensitive to air pollutants. Through the temperature stratification analysis, we found that temperature could modify the impacts of air pollution on daily incidence of influenza with high temperature exacerbating the impact of air pollutants. At high temperature layer, male and the groups aged 0–6 years and 18–64 years were more sensitive to air pollution. Conclusion Temperature modified the relationship between air pollution and daily incidence of influenza and high temperature would exacerbate the effects of air pollutants in Ningbo.

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