The Influence Of Ti, Nb And V On The Hot Ductility Of As-Cast Microalloyed Steels,
2020
Missouri University of Science and Technology
The Influence Of Ti, Nb And V On The Hot Ductility Of As-Cast Microalloyed Steels, Madhuri Varadarajan, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh
Materials Science and Engineering Faculty Research & Creative Works
Microalloying with Ti, Nb and V, both individually and in combination, is a common method for producing steels with high strength and toughness. However, interaction with other elements and impurities can lead to cracking during continuous casting and rolling. The hot ductility of commercially cast V, Nb and Nb-V-Ti steels has been investigated using two experimental methods: tensile testing utilizing a servo-hydraulic load frame with a resistance furnace and thermomechanical testing using rapid joule heating. The temperature-dependent ductility of these steels is compared for both test methods. Factors that influence the ductility of these steels are discussed.
New Experimental Apparatus To Investigate Hot Tearing Behavior In Steel,
2020
Missouri University of Science and Technology
New Experimental Apparatus To Investigate Hot Tearing Behavior In Steel, Yanru Lu, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh, Mario F. Buchely
Materials Science and Engineering Faculty Research & Creative Works
Hot tearing is a complex thermomechanical phenomenon occurring in the semi-solid region. Strain in this region can induce cracking and localized alloying element segregation. An apparatus for investigating hot tearing was developed utilizing a servo-motor controlled cylinder to apply a pre-determined amount of strain to the solidifying shell. A special mold was developed using filling and solidification modeling to ensure that dendrite growth was perpendicular to applied strain. A computer-automated system was utilized to control the strain and strain rate and measure the force and displacement. Solidification experiments utilizing AISI 1020 steel validated the apparatus capabilities and optimized testing parameters.
Peritectic Behavior Detection In The Fe-C-Mn-Al-Si Steel System Using Fiber Optic Temperature Mapping,
2020
Missouri University of Science and Technology
Peritectic Behavior Detection In The Fe-C-Mn-Al-Si Steel System Using Fiber Optic Temperature Mapping, Muhammad Roman, Damilola Balogun, Rex E. Gerald Ii, Laura Bartlett, Jie Huang, Ronald J. O'Malley
Materials Science and Engineering Faculty Research & Creative Works
Peritectic reactions can cause surface defects and breakouts in continuous casting and the peritectic region is often avoided by adjusting the chemical composition of the steel to cast outside of the peritectic sensitivity range. However, the combined effects of C, Mn, Al, and Si on the boundaries that map peritectic region are still disputed for many advanced high strength steel grades. An apparatus for performing controlled solidification experiments is being developed to characterize the effects of chemical composition on the uniformity of shell growth during solidification using a copper chill mold with an embedded fiber-optic temperature sensor that enables high …
Scale Formation On 430 Stainless Steel In A Simulated Slab Combustion Reheat Furnace Atmosphere,
2020
Missouri University of Science and Technology
Scale Formation On 430 Stainless Steel In A Simulated Slab Combustion Reheat Furnace Atmosphere, Richard Osei, Semen Naumovich Lekakh, Ronald J. O'Malley
Materials Science and Engineering Faculty Research & Creative Works
Scale formed during slab reheating can be difficult to remove by high-pressure descaling, having a negative impact hot roll surface quality. A large-capacity thermogravimetric apparatus that replicates the combustion atmosphere and temperature in a slab reheat furnace was used to investigate scale formation on 430 stainless steel. Effects of reheating parameters (temperature, time and atmosphere) on oxidation kinetics were investigated. Oxidized samples were characterized by scanning electron microscopy, Raman spectroscopy and x-ray diffraction to document the microstructure and morphology of scale. Mechanisms for the formation of multi-layered oxide structures that complicate oxidation kinetics and scale removal are discussed.
A Modified Johnson-Cook Model Incorporating The Effect Of Grain Size On Flow Stress,
2020
Missouri University of Science and Technology
A Modified Johnson-Cook Model Incorporating The Effect Of Grain Size On Flow Stress, S. Ganguly, Mario F. Buchely, K. Chandrashekhara, Semen Naumovich Lekakh, Ronald J. O'Malley
Materials Science and Engineering Faculty Research & Creative Works
The mechanical properties of steel are influenced by grain size, which can change through mechanisms such as nucleation and growth at elevated temperatures. However, the classic Johnson-Cook model that is widely used in hot deformation simulations does not consider the effect of grain size on flow stress. In this study, the Johnson-Cook model was modified to incorporate the effects of austenite grain size on flow stress. A finite element model was employed to characterize the effects of grain size on the flow stress for different steel grades over a range of temperatures (900⁰ to 1300⁰). Simulation results show good agreement …
Processing And Properties Of Medium-Mn Trip Steel To Obtain A Two-Stage Trip Behavior,
2020
Missouri University of Science and Technology
Processing And Properties Of Medium-Mn Trip Steel To Obtain A Two-Stage Trip Behavior, D. M. Field, L. G. Garza-Martinez, D. C. Van Aken
Materials Science and Engineering Faculty Research & Creative Works
Two medium-Mn steels of nominal composition 0.15C-2.0Si-10.5Mn-(0.75, 1.5) Al-0.04Nb-balFe (wt pct) were processed to produce sub-micron grain sizes of 0.65 and 0.80 μm. Mechanical testing was performed in three successive conditions: hot rolled, intercritically annealed, and cold rolled with subsequent intercritical annealing. Intercritical annealing was performed at 923 K for 20 hours. Electron-backscattered diffraction and X-ray diffraction were utilized to characterize the microstructure, consisting of α-ferrite, α-martensite, ε-martensite, and γ-austenite. Microstructural constituents were tracked during tensile deformation, and it was found that both steels exhibited two-stage TRIP with γ-austenite martensitically transforming first to ε-martensite and as strain increased ε-martensite transformed …
Numerical Study Of Paraffin Wax Melting In A Cavity With A Gradient Of Hot Wall Inclination,
2020
Teknik Mesin, Sekolah Tinggi Teknologi Ronggolawe, Jawa Tengah 58315, Indonesia
Numerical Study Of Paraffin Wax Melting In A Cavity With A Gradient Of Hot Wall Inclination, Agus Dwi Korawan
Makara Journal of Technology
The melting of a phase change material (PCM) in a cavity with a gradient of hot wall inclination was simulated numerically using five models, namely, Model-A, Model-B, Model-C, Model-D, and Model-E with gradients of −2, −4, ∞, 4, and 2, respectively. The PCM was paraffin wax, which was melted using an enthalpy porosity technique with a pressure-based method. Model-A was found to be the best model. For the completion of the melting process, the models were assigned with the liquid fraction of 1. Model-A required the shortest time, followed by Model-B, Model-C, Model-E, and Model-D, respectively. Compared with Model-C, Model-A …
Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices,
2020
Boise State University
Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong
Boise State University Theses and Dissertations
For magnetic shape memory (MSM) alloys, a magnetic field stimulates a shape change. We use the shape change to build devices such as micro-actuators, sensors, and microfluidic pumps. Currently, (as a novel technology,) devices suffer from some material and magnetic driver shortcomings. Here we address the issues related to operating temperature, repeatability, failure, and magnetic driver development. To increase the operating temperature of the MSM material, we alloyed Fe and Cu to Ni-Mn-Ga. We showed that the element-specific contribution to the valence electron density as parameter systematically determines the effect of each element on the variation of the martensite transformation …
A Spatially Distributed Fiber-Optic Temperature Sensor For Applications In The Steel Industry,
2020
Missouri University of Science and Technology
A Spatially Distributed Fiber-Optic Temperature Sensor For Applications In The Steel Industry, Muhammad Roman, Damilola Balogun, Yiyang Zuang, Rex E. Gerald Ii, Laura Bartlett, Ronald J. O'Malley, Jie Huang
Materials Science and Engineering Faculty Research & Creative Works
This paper presents a spatially distributed fiber-optic sensor system designed for demanding applications, like temperature measurements in the steel industry. The sensor system employed optical frequency domain reflectometry (OFDR) to interrogate Rayleigh backscattering signals in single-mode optical fibers. Temperature measurements employing the OFDR system were compared with conventional thermocouple measurements, accentuating the spatially distributed sensing capability of the fiber-optic system. Experiments were designed and conducted to test the spatial thermal mapping capability of the fiber-optic temperature measurement system. Experimental simulations provided evidence that the optical fiber system could resolve closely spaced temperature features, due to the high spatial resolution and …
A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion,
2020
Western Michigan University
A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco
Masters Theses
Metal additive manufacturing is an enabling technology for the rapid prototyping and manufacturing of geometrically complex parts that would otherwise be difficult or impossible to manufacture. However, the manufacturing process can produce undesired residual stresses and distortions. The first part of the work describes the implementation of a multiscale, thermo-mechanical simulation modeling the metal powder bed fusion additive manufacturing process. NASA’s Micromechanics Analysis Code was is to incorporate the microscale effects of an evolving material porosity on the predicted macroscale residual fields. The simulation shows that modeling an evolving material porosity, as the material transitions from a metal powder to …
Effects Of Ring Rolling On Grain Size In Inconel 718 And Waspaloy,
2020
California Polytechnic State University, San Luis Obispo
Effects Of Ring Rolling On Grain Size In Inconel 718 And Waspaloy, David Webster
Materials Engineering
Carlton Forge Works, an industry leader in the manufacture of rolled rings, has observed anomalous grain structures in parts made from Inconel 718 and Waspaloy. These take the form of unusually large grains at the surface of the rings, causing them to fail industry grain size standards. Grain size testing is a critical part of evaluating parts before they are used as grain size and structure control many mechanical properties including creep resistance, low and high cycle fatigue life, and yield strength. These unusually large grains are only present within the first tenth of an inch of the surface of …
Microstructure And Tensile Properties Of Close-Die Forged Ti-6al-4v Aircraft Engine Mount,
2020
California Polytechnic State University, San Luis Obispo
Microstructure And Tensile Properties Of Close-Die Forged Ti-6al-4v Aircraft Engine Mount, Renee Roeder, Nick Chen, Michael Viksne
Materials Engineering
The microstructural characteristics of a Ti-6Al-4V close-die forging that passes yield strength specifications are examined and found to be consistent with literature recommendations. Originally, the intent was to compare the microstructure of a forging that passed specification to the microstructure of a forging that did not pass specifications using the imaging software ImageJ. Due to time and safety constraints considering the COVID-19 pandemic, the data that is presented is incomplete data on only the forging that passes specifications. There are no comparisons between the forging that did not pass and the forging that passed.
Pitting Corrosion Of Oerlikon’S Abrasion Resistant Ferritic Stainless Steels,
2020
California Polytechnic State University, San Luis Obispo
Pitting Corrosion Of Oerlikon’S Abrasion Resistant Ferritic Stainless Steels, Matthew P. Nalty, Emma Wagstaff
Materials Engineering
Existing hardfacing coatings for hydraulic cylinders and brake disc applications crack during use leaving the components susceptible to corrosion. To address this problem, Oerlikon has designed three new alloys to be abrasion and corrosion resistant. This paper reviews the literature necessary to understand and quantify pitting resistance of stainless-steel alloys. It documents one round of testing ASTM G48 method A: Ferric Chloride Pitting Test of Stainless Steels on the new alloys P72-X9, P72-X13, P129-X9, as well as samples of 431, 316, and 2205 stainless steels. This paper also discusses improvements to the G48 testing method and industry use of the …
Alternative To Custom 450© Stainless Steel For Use In Investment Cast Golf Club Heads,
2020
California Polytechnic State University, San Luis Obispo
Alternative To Custom 450© Stainless Steel For Use In Investment Cast Golf Club Heads, William Henry Armstrong Iv, Davis Martin Loen
Materials Engineering
This investigation seeks to improve on the mechanical property of yield strength, while maintaining 10% elongation prior to fracture observed with of Custom 450 stainless steel in an air-melted investment casting operation. Improving this performance includes an additional heat treatment step of homogenization, as well as replacing the alloy. After identifying and downselecting available high strength stainless steels, a trial of Custom 455 stainless steel is recommended due to its high strength compared to the other alternative alloys. A trial has been developed to analyze the effect air melting has on the chemical composition and mechanical properties of Custom 455 …
Failure Analysis Of Investment Cast Near-Alpha Titanium Alloys,
2020
California Polytechnic State University, San Luis Obispo
Failure Analysis Of Investment Cast Near-Alpha Titanium Alloys, Garrett Ryan Bader, Jonathan Anton Linquist
Materials Engineering
In this project, fracture surfaces of three titanium investment castings were studied as part of a failure analysis on a TaylorMade metalwood. The crack formation occurred between investment cast Ti 9-1-1 and rolled Ti 6-4 joined by laser beam welding. The microstructure of the Ti 9-1-1 contained alpha colonies in large prior beta grains, while the Ti 6-4 was primarily Widmanstätten in basket weave morphology, refined with subsequent rolling. Over a period of cyclic loading, cracking occurred at the face-sole transition in the metalwoods that had been cast from a certain supplier B, while metalwoods that had undergone similar treatment …
Effects Of Surface Finish On High Cycle Fatigue Of Inconel 718,
2020
California Polytechnic State University, San Luis Obispo
Effects Of Surface Finish On High Cycle Fatigue Of Inconel 718, Jessica A. Mcroskey, Matthew Busse
Materials Engineering
Inconel 718 is a nickel-based superalloy and commonly used rocket engine material due to its excellent properties at elevated temperatures. Its fatigue life relies heavily on the surface roughness, as fatigue introduces and propagates cracks at the surface. Part standards set by Aerojet Rocketdyne typically necessitate surface roughness values from 64 to 125 Ra. However, surface topography and residual stresses incurred from the finishing process also affect the fatigue performance. The specific goal of the project is to perform a literature review and write experimental methods to determine how the surface roughness, topography, and residual stresses from turning, grit blasting, …
The Effect Of Distal Core Flattening And Heat Treatment On 304 Stainless Steel Guide Wires,
2020
California Polytechnic State University, San Luis Obispo
The Effect Of Distal Core Flattening And Heat Treatment On 304 Stainless Steel Guide Wires, Andrew Spencer Yap, Bryce Eric Veit, Matthew Frederick Lopez Villena
Materials Engineering
The mechanical response of 304 stainless steel guide wires due to different temper conditions and amounts of flattening is to be explored in this project. For this specific project, there is no public literature on the mechanical properties of guide wires with the above conditions through tensile testing or Turns to Failure Testing. To address this, the project with Abbott Vascular will measure the mechanical properties of guide wires using the aforementioned factors. Due to a lack of previous literature on this research topic, there are no quantitative goals for the project, however, any new research compiled in this area …
Effects Of New And Recycle Flux On The Mechanical Properties Of Submerged Arc Welded (Saw) Line Pipe Grade X52m And X65m,
2020
Universiti Malaya
Effects Of New And Recycle Flux On The Mechanical Properties Of Submerged Arc Welded (Saw) Line Pipe Grade X52m And X65m, Taib Meor Mohd Adli
Student Works (2020-2029)
Two line pipe grade X52M and X65M were manufactured using submerged arc welding process. For each grade, two different welding flux condition were simulated, i.e. 100% new flux and 100% recycle flux. The flux used was aluminate basic type trade name OP 132. The outside diameter and wall thickness for X52M was 610mm x 12.7mm and for X65M was 762mm x 14.3mm. Lower weld re-entrant angle and higher weld bead height were observed in recycle flux condition. Lower weld manganese content recorded in recycle flux condition. And lower mechanical tests (i.e. tensile, impact, and hardness) value reported for recycle flux …
Experimental Performance Evaluation Of A Hyper-Branched Polymer Electrolyte For Rechargeable Li-Air Batteries,
2020
Kettering University
Experimental Performance Evaluation Of A Hyper-Branched Polymer Electrolyte For Rechargeable Li-Air Batteries, Susanta K. Das, Joel Berry, Abhijit Sarkar
Mechanical Engineering Publications
A hyper-branched polymer (HBP) electrolyte is synthesized for rechargeable lithium-air (Li-air) battery cell and experimentally evaluated its performance in actual battery cell environment. Several real-world battery cells were fabricated with synthesized HBP electrolyte, pure lithium metal as anode and an oxygen permeable air cathode to evaluate reproducibility of the rechargeable Li-air battery cell. The effect of various conditions such as various HBP based electrolytes, discharge current −0.1~0.5 mA, cathode preparation processes and carbon contents on the battery cell performance were experimentally evaluated using the fabricated battery cells under dry air condition. Detailed HBP electrolyte synthesis procedures and experimental performance evaluation …
Discontinuous Grain Boundaries Of Forged René 41,
2020
California Polytechnic State University, San Luis Obispo
Discontinuous Grain Boundaries Of Forged René 41, Aaron Rabin, Bryce Bitter
Materials Engineering
Certain nickel-based alloys, particularly René 41, characteristically have many low-angle grain boundaries (grain arrangements of less than 15 degrees), present in the microstructure of an in-use component. Frequently, these low-angle grain boundaries are not optically visible after the etching process, leading to the phenomena of discontinuous grain boundaries. There exists a risk for René 41 grain boundary characterization; since one cannot assume that a grain boundary continues beyond a discontinuity, the grain size requirements become difficult to meet. Despite favorable characteristics of René 41, such as the corrosion and oxidation resistance coupled with excellent strength at high temperatures, the risks …
