Mathematical Model Approach to the Solidification of Different Geometry Ingots and the Development of Shrinkage Defects in them

2019 ◽  
Vol 945 ◽  
pp. 893-898
Author(s):  
Dmitry V. Rutsky ◽  
N.A. Zyuban ◽  
S.B. Gamanyuk
Keyword(s):  
Slenderness Ratio ◽  
Large Diameter ◽  
Rolled Steel ◽  
Metal Solidification ◽  
Factors Affecting ◽  
Hot Top ◽  
Axial Porosity ◽  
Shrinkage Defects ◽  
Axial Defects ◽  
Experimental Data Analysis

A mathematical modeling approach as well as experimental data analysis have made it possible to establish significant factors affecting the relative diameter of the axial porosity zone. The minimal values of this parameter determine if the ingot can be used for the fabrication of rolled steel rods over 300 mm in diameter, because chill extensive axial defects prevent from producing high quality bars of a large diameter. Commercial information analysis and experimental results have enabled to develop a model relating the axial porosity zone dimension, ingot geometry and process parameters of teeming 6.61 ton and 7.0 ton ingots. The improvement of the model obtained has enabled to establish that the axial porosity zone is primarily affected by the following factors: hot top size, slenderness ratio, the H/D ratio and insulation heat capacity. When these parameters are controlled to reduce the relative diameter of the axial porosity zone, the number of shrinkage defects decreases and the quality of large diameter rolled steel becomes better. The proposed ingot geometry improves the direction of the advance of the metal solidification front to the ingot thermal center, located in the hot top. Besides, the solidifying metal is better fed with the hot top melt.

Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li
Keyword(s):  
Process Parameters ◽  
Large Diameter ◽  
Dimensional Accuracy ◽  
Optimization Method ◽  
Main Process ◽  
Shape Accuracy ◽  
Line Pipe ◽  
Factors Affecting ◽  
Array Optimization

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

Factors affecting the rate of milk flow in pipeline milking machines

1965 ◽  
Vol 5 (17) ◽  
pp. 115
Author(s):  
DJ Clarke ◽  
AK Lascelles
Keyword(s):  
Large Diameter ◽  
Factorial Experiment ◽  
Factors Affecting ◽  
Milk Flow

A factorial experiment has been carried out to determine the effects of varying the level of vacuum, air admission, and reserve air on milking rate and the amount of strippings, in high pipeline, low pipeline, and large diameter low pipeline milking machines. The low pipeline and the large diameter low pipeline machines were found to milk 10.1 and 12.1 per cent faster, respectively, than the high pipeline machine. The large diameter low pipeline operating without air admission was 6.3-7.5 per cent faster than the low pipeline machine operating with and without air admission. Milking rate was 16.1 per cent faster at 15 than at 12 inches Hg vacuum and about 6 per cent faster at 17 and 5 cubic feet per minute (c.f.m.) reserve air than at no reserve air. The admission of air at the claw piece resulted in 9 per cent faster milking with the high pipeline and 9.5 per cent slower milking with the large diameter low pipeline machine. There was no difference in milking rate in the low pipeline machine with or without air admission. The fastest milking rate was observed with the large diameter low pipeline without air admission. However, this system probably has no real advantage over the low pipeline providing the diameter of milk pipe of the latter is sufficient to cope with high rates of milk flow.

Understanding and Mitigating Under-Deposit Corrosion in Large Diameter Crude Oil Pipelines: A Progress Report

2008 ◽  
Author(s):  
T. D. Place ◽  
Michael R. Holm ◽  
Colin Cathrea ◽  
Tom Ignacz
Keyword(s):  
Bacterial Species ◽  
Large Diameter ◽  
Progress Report ◽  
Solid Particles ◽  
Test Method ◽  
Internal Corrosion ◽  
Factors Affecting ◽  
Transmission Pipeline ◽  
Emulsified Water ◽  
Batch Treatment

This paper is an exploration of factors affecting internal corrosion of transmission pipeline systems (<0.5% S&W), as well as a progress report on research aimed at improving chemical mitigation of this threat in heavy oil product streams. Typical pipeline corrodents and corrodent transport mechanisms are explored. Transmission quality hydrocarbon products are shown to carry micro-emulsified water, various solid particles, solid particles with micro-attached water, and bacteria. While micro-emulsified water can be considered benign owing its ability to be transported harmlessly without accumulation; water-wetted solid particles have sufficient density to reach the pipe floor. Patterns of internal corrosion on a transmission pipeline are used to demonstrate the significance of solids accumulation leading to under-deposit corrosion. Analysis of pipeline sludge reveals significant populations of different bacterial species indicating the existence of a robust biomass capable of creating or sustaining a corrosive environment. Corrosivity testing of pipeline sludges was performed using two static autoclave coupon methods. One test method demonstrated that the addition of chemical inhibitor directly to the pipeline sludge could reduce corrosion rates as effectively as batch treatment of a clean coupon. A rotating mechanical contactor was designed and built to facilitate the blending of corrosion inhibitor with pipeline sludge under ‘like-pipe’ flow conditions, but results of sludge corrosivity testing using this device are not yet available.

Analysis on Segment Floating in the Construction of Large-Diameter Crossing-River Shield Tunnel

2015 ◽  
Vol 724 ◽  
pp. 17-21
Author(s):  
Run Lai Zhang ◽  
Li Ming Tang ◽  
Kun Tang
Keyword(s):  
Frictional Force ◽  
Large Diameter ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Factors Affecting ◽  
Grouting Pressure ◽  
Rapid Setting ◽  
Grouting Material ◽  
Longitudinal Stiffness ◽  
Initial Solidification

Segment floating is a common problem met in the construction of large-diameter crossing-river shield tunnel. The factors affecting segment floating are discussed first and analyzed by numerical simulation, including the properties of grouting material, the speed of shield tunneling, grouting pressure difference, the tunnel longitudinal stiffness, frictional force between segment rings and weight of the supporting system. The simulation results indicate that segment floating will reduce by shortening slurry’s initial solidification time, slowing shielding speed, improving the tunnel longitudinal stiffness as well as increasing the frictional force between segment rings. And some measures are given such as applying new rapid-setting slurries, shear pins, rubber mats with high friction coefficient and pre-stressed bolts

Resistance of Soil to a Vertically Vibrating Pile

2013 ◽  
Vol 712-715 ◽  
pp. 979-983
Author(s):  
Zhan Shi Gao ◽  
Qing Ren
Keyword(s):  
Slenderness Ratio ◽  
Damping Ratio ◽  
Large Diameter ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Vertical Vibration ◽  
Vibration Model ◽  
Couple Effect ◽  
Soil Dynamic ◽  
Strain Model

Based on the plane strain model, a three-dimensional vibration model was setup for soil dynamic response of soil surrounding large diameter pile. An accurate analytical solution was got by considering the couple effect of vertical and horizontal displacement of soil. Through the discussion parameters slenderness ratio (L/d), hysteretic damping ratio (Ds,Dv) and soil Poisson's ratio (ν),it is concluded that they are very important for the vertical vibration propproperties of soil impedance.

scholarly journals Factors affecting fatigue strength of hot-rolled steel sheets corroded with salt-water.

1985 ◽  
Vol 34 (385) ◽  
pp. 1211-1216
Author(s):  
Kazuyoshi OGAWA ◽  
Katsushi SARUKI ◽  
Takashi ASANO ◽  
Ken-ichi SUZUKI
Keyword(s):  
Fatigue Strength ◽  
Salt Water ◽  
Rolled Steel ◽  
Factors Affecting ◽  
Steel Sheets ◽  
Hot Rolled ◽  
Hot Rolled Steel
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