Evaluation of Cooling Performance in Intensive Cooling with High Water Flow Rate and Effect of Controlled Rolling Just after Cooling on Mechanical Properties

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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Osmotic destruction of Saccharomyces cerevisiae is not related to a high water flow rate across the membrane

Biochemical Engineering Journal ◽

10.1016/s1369-703x(01)00145-0 ◽

2001 ◽

Vol 9 (3) ◽

pp. 205-210 ◽

Cited By ~ 6

Author(s):

Laurent Beney ◽

Iñigo Martı́nez de Marañón ◽

Pierre-André Marechal ◽

Sylvie Moundanga ◽

Patrick Gervais

Keyword(s):

Saccharomyces Cerevisiae ◽

Water Flow ◽

Flow Rate ◽

Water Flow Rate ◽

High Water

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Microstructure and Mechanical Properties of Hot-Stamped 3.2t Boron Steels according to Water Flow Rate in Direct Water Quenching Process

Korean Journal of Materials Research ◽

10.3740/mrsk.2020.30.12.693 ◽

2020 ◽

Vol 30 (12) ◽

pp. 693-700

Author(s):

Hyeon Tae Park ◽

◽

Eui Pyo Kwon ◽

Ik Tae Im

Keyword(s):

Mechanical Properties ◽

Water Flow ◽

Flow Rate ◽

Water Flow Rate ◽

Water Quenching ◽

Microstructure And Mechanical Properties ◽

Quenching Process ◽

Boron Steels

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

Pressure Vessel and Piping Codes and Standards ◽

10.1115/pvp2002-1231 ◽

2002 ◽

Cited By ~ 1

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.

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Study on Enhancement of Sub-Cooled Flow Boiling Heat Transfer and Critical Heat Flux of Solid-Water Two-Phase Mixture

10th International Conference on Nuclear Engineering, Volume 3 ◽

10.1115/icone10-22470 ◽

2002 ◽

Author(s):

Yasuo Koizumi ◽

Tomoyuki Suzuki ◽

Hiroyasu Ohtake

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Water Flow ◽

Flow Rate ◽

Boiling Heat Transfer ◽

Water Flow Rate ◽

Flow Region ◽

High Water ◽

Water Velocity ◽

Rate Region

The influence of particle introduction into a subcooled water flow on boiling heat transfer and critical heat flux (CHF) was examined. When the water velocity was low, the particles crowded on the bottom wall of the flow channel and flowed just like sliding on the wall. When the water velocity was high, the particles were well dispersed in the water flow. In the non-boiling region, the heat transfer was augmented by the introduction of the particles into the water flow. As the introduction of the particles were increased, the augmentation was also increased in the high water flow rate region. However, it was independent upon the particle introduction rate in the low water flow rate region. The onset of boiling was delayed by the particle inclusion. The boiling heat transfer was enhanced by the particles. However, it was rather decreased in the high heat flux fully-developed-boiling region. The CHF was decreased by the particle inclusion in the low water flow region and was not affected in the high water flow region.

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Experimental Research on Heat Transfer of Closed Cooling Tower with Packing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.960-961.614 ◽

2014 ◽

Vol 960-961 ◽

pp. 614-620 ◽

Cited By ~ 1

Author(s):

Ya Su Zhou ◽

Xiao Ding ◽

Wei Xie

Keyword(s):

Water Flow ◽

Flow Rate ◽

Cooling Tower ◽

Water Flow Rate ◽

Cooling Water ◽

Cocurrent Flow ◽

Inlet Temperature ◽

Cooling Performance ◽

Cooling Water Flow Rate ◽

Better Than

Three different structural types of closed cooling tower (CCT) and two cooling water flow directions were considered. The experimental study were done on the cooling performance of influences of inlet air dry and wet bulb temperature, cooling water flow rate and inlet temperature, air flow rate and spray density. The experimental results show that the cooling performance of CCT with packing is obviously better than non-packing cooling tower in 7%~18.4%. And the cooling performance of CCT with packing on top and coil underneath is slightly better than CCT with coil on top and packing underneath in 4.9%. In the same conditions the cooling performance of CCT with packing under cooling water cocurrent-flow is better than that cooling water countercurrent-flow in 3.2%~9.6%. Therefore, the closed cooling tower structure with the cooling water path in bottom and out top, and with packing on top and coil underneath is recommended.

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Experimental Characterization of a Modified Airlift Pump

Volume 7: Fluids Engineering Systems and Technologies ◽

10.1115/imece2014-39899 ◽

2014 ◽

Author(s):

Afshin Goharzadeh ◽

Keegan Fernandes

Keyword(s):

Water Flow ◽

Flow Rate ◽

High Speed ◽

Water Flow Rate ◽

High Speed Photography ◽

Two Phase ◽

Inner Diameter ◽

Airlift Pump ◽

Flow Map ◽

Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

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