Materials Science and Engineering Commons^™

Modelling The Softening Behaviour During Galvanizing Of Various Steel Grades, Kevin Banks, Rorisang Maubane, Thabang Makwena

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Modelling The Softening Behaviour During Galvanizing Of Various Steel Grades, Kevin Banks, Rorisang Maubane, Thabang Makwena

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Temperature Distributions Influencing Lateral Spread In Industrial Hot Rolling, Baohui Tian, Siegfried Kleber, Silvia Zinner, Peter Markiewicz

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Analysis Of Fatigue Crack Propagation In Welded Steels, Roberto Angelo Demarte

Master's Theses (2009 -)

This thesis presents the study of fatigue crack propagation in a low carbon steel (ASTM A36) and two different weld metals (AWS A5.18 and AWS A5.28). Fatigue crack propagation data for each weld wire is of interest because of its use for predicting and analyzing service failures. Fatigue crack growth test specimens were developed and fabricated for the low carbon steel base metal and for each weld wire. Weld specimens were stress relieved prior to fatigue testing. Specimens were tested on a closed-loop servo hydraulic test machine at two different load ratios. Fatigue test data was collected to characterize both …

A Study On Non-Metallic Inclusions In Foundry Steel Process, Marc Leonard Harris

Masters Theses

"The effects of sample area and automated SEM/EDS feature analysis parameters (step size, magnification and threshold) on nonmetallic inclusion characterization results has been investigated and optimized. A post-processing program was developed to automatically determine average inclusion chemistry, total element concentrations within inclusions, and for generating joint ternary diagrams with size visualization for representing nonmetallic inclusion populations. Using these tools the evolution of nonmetallic inclusions was examined for 4320 steel at a participating industrial steel foundry. The steel was sampled throughout electric arc furnace melting through ladle refining to the final casting where an in-mold sampling procedure was developed to procure …

Carbon Transfer From Magnesia-Graphite Ladle Refractories To Ultra-Low Carbon Steel, Andrew Arthur Russo

Masters Theses

"Ultra-low carbon steels are utilized in processes which require maximum ductility. Increases in interstitial carbon lower the ductility of steel; therefore, it is important to examine possible sources of carbon. The refractory ladle lining is one such source. Ladle refractories often contain graphite for its desirable thermal shock and slag corrosion resistance. This graphite is a possible source of carbon increase in ultra-low carbon steels. The goal of this research is to understand and evaluate the mechanisms by which carbon transfers to ultra-low carbon steel from magnesia-graphite ladle refractory.

Laboratory dip tests were performed in a vacuum induction furnace under …

Heterogeneous Thermal Effects On Structural-Grade Steel, Eric Wickersham

Williams Honors College, Honors Research Projects

The AISC Steel Construction Manual covers structural steel design while at atmospheric and elevated temperatures. The manual does not, though, cover what happens to the steel after it has cooled from elevated temperatures. To fill in this knowledge gap, A36 steel was studied with respect to three main criteria: time, temperature, and cooling. Time was sub-divided into a standard burn (17-20min) and a prolonged burn (90min). Temperature was sub-divided into an average burn (600-800⁰F) and an extreme burn (>1200⁰F). To reach such temperatures, a forge was constructed and used during the burning process. Cooling was sub-divided into standard (air …

The Examination Of Stress Corrosion Cracking In High Strength Carbon Steel Through Combined Mechanical-Electrochemical Testing, Jacob Sines

Williams Honors College, Honors Research Projects

Through the analysis of materials and environments seen in industry a better understanding of the fundamentals behind degradation mechanisms can be observed. The scope of this project was to better understand the fundamentals behind the degradation of high strength pipeline steels in a lab setting to simulate an environment seen in industry. Specifically the degradation mechanisms of high and nearly neutral pH stress corrosion cracking were examined in environments that simulated oil and gas pipelines buried in soil. Experimentation was carried out utilizing X65 carbon steel specimen, a Gamry potentiostat, a CORTEST proof ring, a CORTEST slow strain rate machine, …

An Intercritical Heat Treatment Study Of High Strength, Microalloyed Ferrous Open Die Forgings, Kelly Elizabeth Stewart

Materials Engineering

High strength, low alloy steel is most commonly utilized in plate or sheet form-with a thickness under 4 in, one unconventional application however, is open die forging where cross-sectional area can be as large as 9.5 in by 11.5 in. When forging to larger section size than one would thermo-mechanically roll sheet steel, a new set of complications, such as variation in microstructure and mechanical properties, arise. This study investigates the heat treatment and processing options needed to negate the inherent microstructural irregularity and Charpy V-Notch (CVN) toughness variation. Intercritical heat treatment—normalizing and then quench and tempering above the A …

Corrosion Resistance Of Enamel Coating Modified By Calcium Silicate And Sand Particle For Steel Reinforcement In Concrete, Fujian Tang

Masters Theses

"Porcelain enamel has stable chemical property in harsh environments such as high temperature, acid and alkaline, and it can also chemically react with substrate reinforcing steel resulting in improved adherence strength. In this study, the corrosion resistances of enamel coating modified by calcium silicate and sand particles, which are designed for improved bond strength with surrounding concrete, were investigated in 3.5 wt% NaCl solution. It consists of two papers that describe the results of the study.

The first paper investigates the corrosion behavior of enamel coating modified by calcium silicate applied to reinforcing steel bar in 3.5 wt% NaCl solution …

Phosphate-Doped Borosilicate Enamel Coating Used To Protect Reinforcing Steel From Corrosion, Xiaoming Cheng

Doctoral Dissertations

"Phosphate-doped sodium borosilicate glasses were developed for enamel coatings to provide corrosion protection for reinforcing steel in concrete. Phosphates have low solubilities in borosilicate glasses, generally less than about 4 mol%, and are incorporated mainly as isolated PO₄^3- and P₂O₇^4- anions, along with some borophosphate bonds. With the addition of P₂O₅, the silicate network is repolymerized and tetrahedral borates are converted to trigonal borates, because the phosphate anions scavenge sodium ions from the borosilicate network. The addition of Al₂O₃ significantly increases the solubility of P₂O …

Compression Testing And Failure Modes Of Steel-Concrete Composite (Sc) Structures For Nuclear Containment, Patrick Michael Wanamaker, Amit H. Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Although being able to provide much cleaner power than burning coal and other fossil fuels, nuclear power plants are still a tough sell to the general public due to their history of being spontaneously dangerous. The containment structures surrounding these nuclear plants, however, can play a huge role in reducing the risks associated with them. Relatively new designs for these containment assemblies, known as SC (steel-concrete composite) structures, aim to increase the strength and durability of the containment facilities while keeping costs down. By varying the spacing between shear studs, the ratio of concrete to steel, and the ratio of …

The Effects Of Heat Treatment On The Grain Growth, Phase Evolution, And Hardness Of Newly Developed Steel-Based Hardfacing Alloys For Industrial Applications, Renee Kuzniar

Materials Engineering

Steel-based hardfacing alloys are welded onto the outside diameter of tool joints in three beads with a slight overlap between welds for underground drilling to prolong the tool joints’ life. Current hardfacing alloys have a shortened life due to cracks occurring in neighboring weld beads. To decrease cracking, the effects of composition and heat treatment on the microstructure was investigated on five alloys. Five small arc-melt circular ingots roughly 1.4 x 0.3 inches were produced. Each sample had varying amounts of C, B, Cr, Mn, Mo, Nb, Si, Ti, V, and W. The carbon levels in the alloys were .91wt%, …

Bacterial Growth On Metal And Non-Metal Surfaces In A Static Bioreactor, Rolan Yuk Loong Liong

Master's Theses

Research was conducted to observe bacterial growth on the surface of metals in a static bioreactor. Metal and non-metal samples were subjected to bacterial exposure (1 day and 9 days). The metal samples were surface treated prior to bacterial exposure. The microstructures of the surface treated samples were analyzed by optical microscopy. After exposure, the microstructures of the samples were analyzed by scanning electron microscopy (SEM). The analysis suggested that microbial attachment on the surface was related to the underlying microstructure of steel. The preferential attachment of microbes could potentially be influenced by cathodic and anodic regions created by the …

Kelvin Probe Electrode For Contactless Potential Measurement On Concrete-Properties And Applications, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

The practical feasibility of using a Kelvin Probe as a novel reference electrode in the measurement of both potential and polarization pulse response of reinforcing steel in concrete is demonstrated. Potential values measured using a KP reflect greater stability and repeatability than can typically be attained with conventional reference electrodes. Duplicate reinforced concrete beam test specimens with well-differentiated centrally corroding rebar segments were analyzed using both the Kelvin Probe (KP) and a conventional Saturated Calomel Electrode (SCE). Potential profile maps were developed using potential values recorded under static conditions with both the SCE and the KP. Nominal polarization resistance was …

Microstructure And Mechanical Properties Of Cold Drawn Steel Wires, Ning Liu

Theses: Doctorates and Masters

Cold drawn eutectoid steel wires have been widely used for a variety of applications, such as suspension bridges, steel cords for automobile tires, and springs. Much research has been done to increase their mechanical strength. With advances in modern production technology, both the drawing speed and the quality of drawn steels have been enhanced. After a careful literature survey, it is obvious that some issues are still controversial. As Y.S. Yang, J.G. Bae and C.G. Park mentioned, the lamellar spacing, thickness and volume fraction of cementites have all reached the nanometer regime, and the conventional theory is not enough to …

Development Of Third Generation Advanced High Strength Steels, Meghan C. Mcgrath

Doctoral Dissertations

"Lightweight duplex steels with combinations of either bainite, acicular ferrite, and austenite or martensite and austenite were investigated as third generation advanced high strength steels targeted for automotive applications. Large additions of manganese (>13 wt%) and carbon (

Duplex steels with different volume fractions of primary δ -ferrite were used to study the crystallography of austenite formed during the peritectic reaction. Solute profiles across the peritectic interface showed aluminum segregated near the interface which promoted bainitic ferrite formation. Thermal treatments were used to manipulate the concentration and type of oxides and the ferrite plate density was found to correlate …

Encapsulation Of High Temperature Phase Change Materials For Thermal Energy Storage, Rupa Nath

USF Tampa Graduate Theses and Dissertations

Thermal energy storage is a major contributor to bridge the gap between energy demand (consumption) and energy production (supply) by concentrating solar power. The utilization of high latent heat storage capability of phase change materials is one of the keys to an efficient way to store thermal energy. However, some of the limitations of the existing technology are the high volumetric expansion and low thermal conductivity of phase change materials (PCMs), low energy density, low operation temperatures and high cost. The present work deals with encapsulated PCM system, which operates at temperatures above 500°C and takes advantage of the heat …

Steel Angle Section Members Under Combined Axial Load And Unsymmetric Bending, Maheshchandra Rajasekharan Phanibhushan

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of an investigation into the experimental and theoretical behavior of steel angle section members under combined axial load and unsymmetric bending. Tests are conducted on a series of six angle section members provided with biaxial pinned-end boundaries about the cross-sectional non-principal axes. The end bending moments and axial load are applied in a quasi-static manner until the member load-carrying capacity is reached. The experimental load-deflection and load-strain curves are recorded. The theoretical analysis is based on a system of both elastic as well as materially nonlinear differential equations. The equations were solved using an iterative …

Friction Stir Lap Welded Advanced High Strength Steels: Microstructure And Mechanical Properties, M. Ghosh, K. Kumar, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Friction stir welding was carried out under different heat input and cooling rates to produce lap joints between high strength martensitic steel sheets. the microstructure of the welds was characterized, and microhardness was evaluated. Joint efficiency was determined by lap shear test. Variation in processing conditions governed total heat input, peak temperature and cooling rate during friction stir welding. Weld nugget microstructure depended principally on cooling rate. the slowest cooling rate promoted ferrite-pearlite and the fastest cooling rate resulted in martensite formation in the weld nugget. the weakest region of all the joints was the heat affected zone, which consists …

Electrochemical Detection For The Corrosion Of Reinforcing Steel In Concrete During Immersion And Drying Cycles, Bing-Li Jia, Fa-He Cao, An-Na Chen, Jian-Qing Zhang

Journal of Electrochemistry

The corrosion behavior of reinforcing steel in concrete under dry-wet cycle condition has been studied by electrochemical noise(EN) compared with the electrochemical impedance spectroscopy(EIS),SEM micrographs and EDS.The statistical method has been employed to analyze the EN data of reinforcing steel in concrete,which revealed three different corrosion stages of reinforcing steel in concrete,including the dissolution of the passive film,the active corrosion and the cumulation of corrosion product.The wavelet transform has also been employed,which indicated that steel in concrete with pH 1 is associated with uniform corrosion,while steel in concrete with pH 3 and pH 7 are associated with localized corrosion,such as …

Numerical/Experimental Investigation Of Plunge Stage And Effect Of Donor Material In Friction Stir Welding, Saptarshi Mandal

Mechanical & Aerospace Engineering Theses & Dissertations

Friction Stir Welding (FSW) was developed in 1991 as a robust solid-state joining technique that uses a specially shaped rotating tool to generate heat and plasticize material around the tool. The tool then mixes plasticized material along the joint line to produce the weld. Over the last decade, FSW has become increasingly popular for welding aluminum. The combination of attractive properties of the weld and cost-efficiency has led researchers to investigate the feasibility of using FSW for steel. One of the major impediments for using friction stir welding for harder materials such as steel is tool wear. It is well-documented …

Synthesis And Characterization Of Atmospheric Pressure Chemically Vapor Deposited Aluminum, Sipeng Gu

Dissertations

This study investigates the use of atmospheric pressure chemical vapor deposition (APCVD) to produce high quality aluminum coatings for corrosion protection of steel. The coatings were produced through thermal decomposition of tri-isobutyl-aluminum (TIBAL) over the 275 to 300°C temperature range. Under optimal deposition conditions, growth rates as high as 1.2 um/min were achieved. X-ray photoelectron spectroscopy, auger electron spectroscopy, glow discharge optical emission spectroscopy and nuclear reaction analysis revealed that the coatings consisted essentially of pure aluminum (~99 at.%) with oxygen and carbon present as minor constituents. The coatings were characterized in terms of their morphological, structural, electrical, and mechanical …

Characterization Of Thermally Diffused Bordie Layers On Aisi 1018 Steel : Residual Stresses (By Synchrotron Radiation) And Microhardness, Joel A. Payne

Theses

Boronization is a thermal diffusion process in which needle like boride layers are formed at the surface of the metallic substrate. The boride coatings formed by the diffusion process have high hardness and strong ware and corrosion resistance. In order for coatings of this nature to be industrially successful, their service life should be long and characterization should be extensive. Measuring the residual stresses of the coatings caters to each of these aspects.

In this study, AISI 1018 steel samples were boronized by a powder-pack process for four hours at 850°C in an argon atmosphere. Characterization techniques included coating thickness, …

Nonlinear Model For Reinforced Concrete Under Cyclic Loading, Aly Said, M. Elmorsi, M. Nehdi

Civil and Environmental Engineering and Construction Faculty Research

Most of the available shear models for reinforced concrete rely on empirical formulations. In this study, a rational shear stress function is used to define the shear stress–strain envelope for reinforced concrete. Cyclic rules are proposed to define the loading, unloading and reloading relationships for reinforced concrete under shear stress reversals. A normal stress function describing the cyclic relationship of concrete under axial stress is also introduced. The proposed functions are verified using experimental data of reinforced concrete panels tested under monotonic and cyclic loading. Subsequently, the normal and shear stress functions along with their cyclic rules are integrated in …

The Localized Corrosion Behavior Of 6% Mo And 316l Stainless Steels In Chloride Media And The Effect Of Applied Mechanical Stress, Houssam El-Din Sabry Ahmed

Archived Theses and Dissertations

Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and super austenitic 6% Mo in acidified 3% NaCl solution at room temperature. Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared to 316L alloy when tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 m V, SCE, the corresponding value for 6% Mo alloy could not be reached up to the potential value of 700 m V, SCE. 316L alloy suffered extremely from crevice …

Study Of Marine Biocorrosion Using Afm And Molecular Techniques, Herbert H.P.Fang, Lichong Xu, Tong Zhang

Journal of Electrochemistry

Biofilm is ubiquitous in nature.However,corrosin caused by biofilm is still by and large overlooked. This presentation is to demonstrate the applications of several newly developed analytical techniques in chemisrty and microbiology for the study of marine biocorrosion on steel. AFM(atomic force microscopy) was applied to investigate the initial formation mechanism of biofilm and the degree of corrosion of steel in polluted seawater. DNA/RNA-related molecular techniques were used to analyze the microbial composition corrosive biofilm. Results showed that microbial corrosion began within six days, and the corroded volume in the increased as a power function of time with an index 2.83. …

Corrosion Of Steel In Sea-Bottom Mud Of Nothern China Sea Area, Gong-Yu Guo, Jing-Lei Zhang, Bao-Rong Hou, Fang-Ying Yang

Journal of Electrochemistry

Corrosion experiments of A₃, 16Mn, 20^# as well as ZCE36-225 steel were carriedout in southern Bohai sea and Qingdao sea areas. The sea-bottom mud in southern Bohai sea areais the sandy mud and that in Qingdao sea area is pure beach sand. In this experiment, the compareing test of two modes with electric connected and non-electric connected modes was carriedout. The experiment results showed that: 1) The corrosion rate of steel in sea-bottom mud has astrong relation with mud types. The corrosion rates of steels in pure beach sand are much higherthan those in sandy mud. 2) …

Atmospheric Corrosion Of Steels In China, Cai-Feng Liang

Journal of Electrochemistry

Data of eight year atmospheric exposures of 17 steels at 7 sites in China were analyzed. The result showed that the most detrimental pollution is sulfur dioxide and chloride ion for corrosion of carbon steels and low alloy weathering steels. This is in accordance with the common knowledge.The effect of sulfur dioxide is serious in the first few years and becomes weak obviously in the later years. The environment factor of humid hot is much more important in long run than the ordinarily acknowledged humidity, pollution for non weathering steels,although it is not obvious in the beginning. If pollution were …

Characterization Of Iron Oxides And Atmospheric Corrosion Of Steel, Sei Jin Oh

Physics Theses & Dissertations

The study of corrosion behavior was performed using three different analytical techniques, which provided information on the formation, development and layering of iron oxides on the corrosion products as a function of atmospheric conditions, exposure time and type of steel. In particular, the protective layer formed on weathering steel was investigated as a function of different amounts of alloying elements in the steel, atmospheric conditions and exposure times. Combined together, the results provided a better understanding of the atmospheric corrosion behavior of steel, and formed a part of database of the atmospheric corrosion characteristics.

Accurate characterization of the iron oxides …