Effects of Water Flow Rate on Fatigue Life of Structural Steels Under Simulated BWR Environment

2007 ◽  
Author(s):  
Akihiko Hirano ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Water Flow ◽  
Flow Rate ◽  
Environmental Effect ◽  
Water Flow Rate ◽  
High Flow ◽  
High Flow Rate ◽  
Sulfur Concentration ◽  
Type 304

Fatigue tests in simulated LWR environment of carbon and stainless steels were performed under high water flow rates between 7 to 10 m/s. For carbon steel, high flow rate of water clearly mitigated the environmental effect on the fatigue life at the high sulfur concentration of 0.016% which caused high environmental effect on a fatigue life. On the contrary, high flow rate of water slightly enhanced the environmental effect at the low sulfur concentration at or less than 0.008% which caused very low environmental effect. These results suggested that the environmental fatigue life under various flow rate conditions should be determined by the combination between the mitigating effect caused by flushing of the severe local environment and the enhancing effect caused by increase in corrosion potential. Low alloy steel showed the similar behavior as carbon steel. For stainless steel, flow rate had little effect on the fatigue life of type 316NG stainless steel. It suggested that there was no role of water flushing. For type 304 and 304L stainless steel, fatigue life has a tendency to decrease with increase in water flow rate. Fatigue lives of type 304 stainless steel under high flow rate of 7 to 10 m/s were shorter than those predicted by proposed fatigue life prediction equation by the Japanese EFT committee. This effect should be considered in an evaluation of environmental fatigue. No water flow effect was found in cast stainless steel.

Effects of Water Flow Rate on Fatigue Life of Carbon and Stainless Steels in Simulated LWR Environment

2004 ◽  
Author(s):  
Akihiko Hirano ◽  
Michiyoshi Yamamoto ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Water Flow ◽  
Flow Rate ◽  
Environmental Effect ◽  
Corrosion Potential ◽  
High Flow ◽  
High Flow Rate ◽  
Sulfur Concentration ◽  
Rate Condition

Fatigue tests in simulated LWR environment of carbon and stainless steels were performed under high water flow rates between 7 to 10 m/s. For carbon steel, high flow rate of water clearly mitigated the environmental effect on a fatigue life at the high sulfur concentration of 0.016 wt% which caused high environmental effect on a fatigue life. On the contrary, high flow rate of water slightly enhanced the environmental effect at the low sulfur concentration at or less than 0.008 wt% which caused very low environmental effect. These results suggested that the environmental fatigue life under various flow rate conditions should be determined by the combination between the mitigating effect caused by flushing of locally severe environment and the enhancing effect caused by increase in corrosion potential. To understand those effects, effects of sulfur concentration on fatigue life for various DO condition were formulated. And corrosion potential under low and high flow rate condition was measured during the fatigue test. Environmental correction factor, Fen, which is the ratio of fatigue lives derived from the fatigue life at room temperature in air divided by that in water to be used for the fatigue life prediction at high flow rate condition was assumed based on the MITI guideline equation and considering the hypothetical fatigue life under sulfur free condition and high corrosion potential condition. This assumption was agreed very well with the test data. For stainless steel, flow rate had little effect on a fatigue life of type 316 stainless steel. It suggested that there was no role of water flushing. For type 304 stainless steel, fatigue life has a tendency to decrease with increase in water flow rate. Fatigue lives of type 304 stainless steel under high flow rate of 7 to 10 m/s were shorter than those predicted by MITI guideline equation. This effect should be considered in an evaluation of environmental fatigue.

Effects of Water Flow Rate on Fatigue Life of Ferritic and Austenitic Steels in Simulated LWR Environment

2002 ◽  
Author(s):  
Akihiko Hirano ◽  
Michiyoshi Yamamoto ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji ◽  
Kunihiro Iida
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Water Flow ◽  
Flow Rate ◽  
Fatigue Testing ◽  
Water Flow Rate ◽  
High Water ◽  
Low Sulfur ◽  
Fatigue Life Reduction

The flow rate of water flowing over a steel surface is considered to be one of the most important factors influencing the fatigue life of the steel, because the water flow produces differences in the local environment. The effect of the water flow rate on the fatigue life of carbon, low alloy, and austenitic stainless steels was therefore investigated experimentally. Fatigue testing of low (S = 0.008 wt%) and high (S = 0.016 wt%) sulfur content carbon steels and a low alloy steel was performed at 289°C for various dissolved oxygen concentrations (DO) of less than 0.01 and 0.05, 0.2, and 1 ppm, and at various water flow rates. Three different strain rates of 0.4, 0.01, and 0.001%/s were used in the fatigue tests. For high sulfur carbon steel (S = 0.016 wt%), the effect of a high water flow rate on mitigating fatigue life reduction was more clearly observed at a lower strain rate, irrespective of the DO. This effect of high water flow rate was most notable at a DO of 0.2 ppm, which was the DO level that produced a significant sulfur effect. This indicates that the mechanism responsible for the mitigation of fatigue life reduction is the flushing effect of the water, which eliminates the locally corrosive environment. For high sulfur carbon steel (S = 0.016 wt%), no benefit of a high water flow rate was found at a DO of 0.01 ppm. This was because the environmental effect is insignificant at this low DO level. For low sulfur carbon steel (S = 0.008 wt%) and low alloy steel (S = 0.008 wt%), a high water flow rate had little effect on mitigating fatigue life reduction even at a DO of 0.2 ppm. This indicates that the sulfur is much less influential in low sulfur steel than in high sulfur steel. Fatigue testing of Type 316 nuclear grade stainless steel (316NG) and Type 316 stainless steel (SUS316) was performed at 289°C and 320°C for DO levels of less than 0.01 and 0.05, and 0.2. For austenitic stainless steel, no mitigating effect at a high water flow rate was found. It should be noted rather that there is a possibility that a high water flow rate decreases the fatigue life because a tendency to a slight decrease in fatigue life with an increasing flow rate was observed.

scholarly journals The Enhancement of Pre-Storage Filtration Efficiency for the Rainwater Harvesting System in Malaysia

2018 ◽  
Vol 152 ◽  
pp. 02015
Author(s):  
Yoong Sion Ong ◽  
Ken Sim Ong ◽  
Y.k. Tan ◽  
Azadeh Ghadimi
Keyword(s):  
Stainless Steel ◽  
Flow Rate ◽  
Rainwater Harvesting ◽  
Filtration Efficiency ◽  
High Flow ◽  
High Flow Rate ◽  
Water Tank ◽  
Filtration System ◽  
Filter Screen ◽  
Water Piping

A conventional design of rainwater harvesting system collects and directs the rainwater through water piping from roof of building to the water storage. The filtration system which locates before the water tank storage and first flush bypass system is the main focus of the research. A filtration system consists of a control volume of filter compartment, filter screen (stainless steel mesh) and water piping that direct the water flow. The filtration efficiency of an existing filter “3P Volume Filter VF1” by industrial company is enhanced. A full scale filter design prototype with filter screen of 1000 μm stainless steel metal mesh is tested to compare with the original filter system design. Three types of water inlet setups are tested. Among the proposed water inlet setups, the 90° inlet setup with extension provides the best filtration rate per unit time, following by the 45° inlet setup. The 45° and 90° inlet setup has similar filtration efficiency at low to medium flow rate while 45° inlet setup has better efficiency at high flow rate. The filtration efficiency with the 90° inlet setup with extension is observed to maintain at highest value at medium to high flow rate. The overall filtration performance achieved by the 90° inlet setup with extension at low to high flow rate is between 34.1 to 35.7%.

Effects of Water Flow Rate on Fatigue Life of Carbon Steel in Simulated LWR Environment Under Low Strain Rate Conditions

2003 ◽  
Vol 125 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Akihiko Hirano ◽  
Michiyoshi Yamamoto ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji ◽  
Kunihiro Iida
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Strain Rate ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Flow Rates ◽  
Life Evaluation ◽  
Significant Difference ◽  
Fatigue Life Evaluation

The flow rate of water flowing on a steel surface is considered to be one of the important factors strongly influencing the fatigue life of the steel, because the water flow produces difference in the local environmental conditions. The effect of the water flow rate on the fatigue life of a carbon steel was thus investigated experimentally. Fatigue testing of the carbon steel was performed at 289°C for various dissolved oxygen contents (DO) of less than 0.01 and 0.05, 0.2, and 1 ppm, and at various water flow rates. Three different strain rates of 0.4, 0.01, and 0.001 %/s were used in the fatigue tests. At the strain rate of 0.4 %/s, no significant difference in fatigue life was observed under the various flow rate conditions. On the other hand, at 0.01 %/s, the fatigue life increased with increasing water flow rate under all DO conditions, such that the fatigue life at a 7 m/s flow rate was about three times longer than that at a 0.3 m/s flow rate. This increase in fatigue life is attributed to increases in the crack initiation life and small-crack propagation life. The major mechanism producing these increases is considered to be the flushing effect on locally corrosive environments at the surface of the metal and in the cracks. At the strain rate of 0.001 %/s, the environmental effect seems to be diminished at flow rates higher than 0.1 m/s. This behavior does not seem to be explained by the flushing effect alone. Based on this experimental evidence, it was concluded that the existing fatigue data obtained for carbon steel under stagnant or relatively low flow rate conditions may provide a conservative basis for fatigue life evaluation. This approach seems useful for characterizing fatigue life evaluation by expressing increasing fatigue life in terms of increasing water flow rate.

K-2217 Effects of Water Flow Rate on Fatigue Life of Carbon Steel in Simulated BWR Environment

2001 ◽  
Vol V.01.1 (0) ◽  
pp. 291-292
Author(s):  
Akihiko HIRANO ◽  
Michiyoshi YAMAMOTO ◽  
Katsumi SAKAGUCHI ◽  
Tetsuo SHOJI ◽  
Kunihiro IIDA
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate

Experiment Study of High-Temperature and High-Flow Rate Naphthenic Acid Corrosion

2011 ◽  
Author(s):  
Ke Jiang ◽  
Xuedong Chen ◽  
Tiecheng Yang ◽  
Zongchuan Qin
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Corrosion Rate ◽  
Flow Rate ◽  
Acid Corrosion ◽  
Naphthenic Acid ◽  
High Flow ◽  
High Flow Rate ◽  
Experimental Results ◽  
Wall Turbulence

The corrosion behaviors of 321 and 316L austenitic stainless steel in high-temperature and high-flow rate naphthenic acid medium were investigated by pipe-flow and jet-impingement method. The influence of temperature and erosion angle on naphthenic acid corrosion resistance for stainless steel was analyzed. The results indicate that the naphthenic acid corrosion rate increased with increasing temperature and velocity. At the same temperature, the corrosion rate at 90° erosion angle is greater than that at 0°. The present experimental results are very close to those in API 581. Simulation results indicate that, where the mutation of flow direction occurs around the specimen, the near-wall turbulence intensities are very large by both experimental methods. Moreover, by comparing both the simulation and experimental results, it can be found that the naphthenic acid corrosion is very severe in areas of high turbulence.

Method to Evaluate Fatigue Life of Carbon Steel Under Simulated Synchronously Changing BWR Condition

2007 ◽  
Author(s):  
Akihiko Hirano ◽  
Kazunari Uchida ◽  
Katsumi Sakaguchi
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Dissolved Oxygen ◽  
Strain Rate ◽  
Oxygen Concentration ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Fatigue Tests ◽  
Dissolved Oxygen Concentration

The environmental fatigue life of carbon steel is influenced by BWR conditions such as water temperature, dissolved oxygen concentration, water flow rate and so on. These parameters change inconstantly during operation of BWR plants and strain rate changes in the structural components due to the temperature change. In general, fatigue life evaluation equations have been formulated based on the fatigue data obtained under constant conditions. To apply these equations to evaluate the fatigue life of actual components, a study is necessary to confirm the applicability of the proposed equations to the changing conditions. In this study, fatigue tests were performed under changing conditions of strain amplitude, strain rate, temperature, dissolved oxygen concentration and water flow rate. It was confirmed that the proposed fatigue life equation could predict the fatigue life under changing conditions.

Modified Rate Approach Method to Evaluate Fatigue Life of Carbon Steel Under Simulated Synchronously Changing BWR Conditions

2006 ◽  
Author(s):  
Akihiko Hirano ◽  
Katsumi Sakaguchi
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Dissolved Oxygen ◽  
Strain Rate ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Fatigue Tests ◽  
Temperature Changes ◽  
Approach Method

The fatigue life of carbon steel is influenced by Boiling Water Reactor (BWR) conditions such as water temperature, dissolved oxygen concentration, water flow rate and so on. These parameters changes constantly during the operation of BWR plants and strain rate changes in the structural components occur because of temperature changes. In general, fatigue life evaluation equations have been formulated based on fatigue data obtained under constant conditions. Before using these equations to evaluate the fatigue life of actual components, a study is necessary to make sure they are applicable to changing conditions. In this study, fatigue tests were performed under changing strain amplitude, strain rate, temperature, dissolved oxygen content, and water flow rate conditions. It was confirmed that the proposed fatigue life equation could predict the fatigue life under practical changing conditions.

scholarly journals Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
Shielded Metal Arc Welding ◽  
Effect Of Water ◽  
Bending Effect ◽  
Metal Arc Welding ◽  
A36 Steel

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.

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