Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 104-107).

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed October 25, 2007) Includes bibliographical references (p. 82-83).

Over the years, industrial partners experienced issues related to inconsistent free ferrite in gray cast iron. In the course of a hot summer and a cold winter, machinability balance varies up to 350%. During warm months it is better and cold months worse. The inconsistent machinability increases the scrap rates by up to 400% and reduces tool life by up to 70%. The ultimate objective of this research is to collaborate with an automotive industrial partner to investigate the periodic machinability variability of gray cast iron engine sleeves, with a goal to reduce the cost and scrap rate of tool inserts. In this study, a significant amount of work was conducted concerning sample preparation for a metallography check. Samples from different months with varying amount of “free ferrite” were collected to study the seasonal effect on their machinability and high-speed machining under similar industrial conditions. Furthermore, a room temperature age strengthening of gray cast iron was conducted to demonstrate how the hardness increase from aging could improve the machinability of gray cast iron. A CBN insert is the second hardest cutting tool after the diamond insert, and is widely used in industry for machining cast iron. It has a high cutting speed is commonly used due to its high hardness and impressive wear resistance. It is known that gray cast iron can naturally age at room temperature or artificially age under a controlled temperature. Under different aging temperatures and times, gray cast iron exhibits a greater hardness after age strengthening, which affects the CBN tool life. The latter is usually limited by flank wear length, however the content of free ferrite in gray cast iron can generate ferrous built-up on the CBN cutting edge and significantly shorten the tool life of the CBN cutting tool. / Thesis / Master of Applied Science (MASc)

No description available.

The goal of this line of research is to add to the existing body of literature on the effect of heat treatments on the microstructure of chrome-bearing white irons and add bend test data to the literature concerning chrome-bearing white irons. This project was intended to support an existing line of research into cast metal-ceramic lattices using chrome white iron as a substitute for sintered ceramic tiles used to defeat projectiles. Chrome-bearing white irons have a substantial quantity of chromium carbides, giving them high hardness and abrasion resistance. Additionally, tiles cast from white iron proved to be more durable than sintered ceramic tiles, breaking into large chunks rather than a powder following an impact. These properties make tiles cast from chrome-bearing white iron a low-cost alternative to sintered carbides. The alloy investigated contained nominally 14 chromium and 3.2 carbon by weight percent. Three-point bend test specimens were cut from cast plates. These specimens were austenitized, air cooled, then tempered prior to three-point bend and hardness testing. The microstructure of the specimens was evaluated using optical microscopy, SEM, and XRD. This line of research revealed that lower austenitization temperatures resulted in a martensitic matrix with fewer, smaller secondary carbides, resulting in higher strength and hardness. In contrast, higher austenitization temperatures produced an austenitic matrix with coarser carbides, resulting in lower strength and hardness. This research did not reveal an appreciable change in ductility over heat treatment temperature. / Master of Science / This research investigates a hard iron alloy capable of replacing expensive ceramics in situations where the goal is to prevent penetration by a projectile. This iron alloy, known as white cast iron, can be cast using typical foundry practices, making it cost-effective. Additionally, the properties can be changed by heat-treatment, a process that involves heating the material to a given temperature, holding it at that temperature for a given amount of time, then cooling the material at a given rate. The results of this research add to the existing understanding of how heat treatment affects the properties of white cast iron. Additionally, this research generated new data about the strength of white cast irons in a three-point bending test, a test not normally used for white cast irons. The research found that high heat-treatment temperatures resulted in a softer white cast iron with lower strength. The structure of the white cast iron treated at these temperatures was predominantly austenite, a soft iron phase, and large carbides, a hard but brittle phase. Temperatures close to the lower end of the temperature range tested resulted in a harder white cast iron with higher strength. The structure of the iron in these conditions contained martensite, a hard iron phase, some austenite, and smaller but more angular carbides.

The rare earth metals cerium, mischmetal, lanthanum, and didymitun were added to irons in the amounts of 0.08 to 0.20 per cent. Silicon and graphite were added to the iron at the electric furnace to change the carbon equivalent of the base metal. The base metal was super-heated to temperatures of 2740º to 2780°F. The molten metal was poured onto the rare earth with a one per cent silicon addition for inoculation. It was then poured into the tensile molds in a temperature range of 2490° to 2540°F. The appearance of the tensile fracture indicated the presence of carbon flotation. The chemical analysis and micro-structure. examination verified this. All of the tensile specimens with carbon equivalent above the eutectic had flotation. As the carbon equivalent increased the carbon flotation increased. The graphite structure in the carbon flotation region was deteriorated from the nodular, and the graphite was nodular in form in the lower portions of the specimens. Cementite was scattered throughout the matrix of all samples except those. with silicon contents above 2.70 per cent. The metal with didymium additions had the most consistent physical properties, while lanthanum produced the lowest physical properties. The tensile and yield values were comparable to those reported in the literature for similar additions. However, the elongation values were low due to the carbon flotation. / Master of Science

Bridges, railways stations, warehouses, bandstands, fountains, shop fronts, lamps, gates and other cast-iron elements can still be found throughout Argentina. Some of these elements are impressive, others humble; some are abandoned, others are still in use. Many are part of important monuments; others are so incorporated into the urban landscape that they almost go unnoticed. When one's attention is drawn to these features, however, a company nameplate and place of origin - 'London', 'Liverpool', 'Glasgow' - is usually visible. These elements are so far from Argentina that their appearance begs several questions: why are most of the visible nameplates British? Are they the same as those found in London, Liverpool and Glasgow, or in former British colonies like India, South Africa or Australia? If so, why? Can we think of these elements as British imperial architecture in Argentina? In what context can their arrival in Argentina be understood? Who commissioned and designed them? Are there more Scottish nameplates than English, or any other? Does it matter? Did these elements act as models that were later copied or imitated by local manufacturers? Did they affect architecture and urban development in Argentina? If architecture reflects the view of a society, what do these elements reflect? Considering the wider context of British cast iron manufacturing, this dissertation asks what role Scotland's burgeoning cast iron industry played in the export of British iron products to Argentina during the late nineteenth and early twentieth centuries. If in recent years historians have reconsidered the specific contributions of Scotland and its people to the growth and expansion of Great Britain as an imperial power, this dissertation takes this analysis into the realm of cast iron as an export industry. If British cast iron was ubiquitous throughout the developed world during this period, how do we begin to understand the Scottish cast iron industry as a major contributor to this trade? Here Argentina is used as a micro-study in an attempt to measure and understand that contribution. In addressing some of the above questions, the dissertation attempts to form a coherent analysis of the architectural, historic, cultural and economic dimensions of the phenomenon of Scottish architectural ironwork in Argentina. In so doing, the study hopes to shed light on larger questions concerning British 'informal' imperialism, considering exports of cast iron as a significant component in Britain's attempts at economic leverage and coercion in Argentina during that country's most dramatic period of development and urbanisation. The dissertation arrives at the conclusion that British cast-iron elements found in Argentina are the same or similar to elements found in Great Britain and its colonial empire because they arrived in Argentina through a process of commercial expansion that involved imperial trade routes, global networks, cooperation between British architects and engineers, as well as migration and the assistance of the pro-British elite in Argentina. It is argued that British iron in general, and Scottish in particular, contributed to the expansion of British power and influence in the region through helping shape the architectural and urban environments of Argentina. To reach this conclusion, the thesis is structured in three sections dealing with the three most significant aspects of the thesis: informal empire in Argentina, the iron trade, and Scottish cast-iron architecture in Argentina.

Helical heating coils are widely used in most conventional electric stoves for many years, these heating coils can reach 600-700°C, which is higher than the ignition point of oil and grease (about 400°C), leading to many fires. Pioneering Technology Inc. has developed a Safe-T Element plate to address such problem. The Safe-T Element plate is manufactured from Gray Cast Iron. However, these plates deform during its use. This study was carried out to investigate the current Safe-T Element design, both experimentally and numerically, in order to determine the root causes behind the deformation problem of the plate, and to suggest changes to the existing design in order to limit its distortion to acceptable targets. A chemical analysis was carried out to establish the type of material of the Safe-T Element plate. Chemical analysis showed that the material of the plate is cast iron. The microstructure of the plate was tested in order to examine its type and homogeneity. Tensile testing was carried to establish the grade of the material, and to calculate the value of its young's modulus and yield strength. Tensile testing indicated that the material of the Safe-T Element plate is close to Gray Cast Iron Class 40. Differential scanning calorimetry testing was carried out to investigate thermal stability of the plate material. This test indicated that material is thermally stable. Thermal cycling testing indicated that the root cause of the deformation problem is elastic thermal buckling. Temperature uniformity tests were carried out. More than 100°C temperature variation in the radial direction was observed. To address the distortion of the plate, an optimum geometry has been suggested based on the findings of the numerical investigation by removing the outer ring from the original design of the plate. / Thesis / Master of Applied Science (MASc)

Foi estudado o efeito da variação do teor de cromo, em 3%, 6% e 9% em massa, na microestrutura, dureza e oxidação de um ferro fundido branco multicomponente. O Thermo-Calc versão 5 foi a ferramenta utilizada para cálculos termodinâmicos que resultaram na previsão das fases formadas para cada liga. Experimentalmente, foram realizados os seguintes estudos: i) caracterização microestrutural das ligas fundidas com os diferentes teores de cromo na condição bruta de fundição; ii) ensaio de dureza na matriz duplamente revenida em cinco diferentes temperaturas entre 400 °C e 600 °C; e iii) ensaio de termogravimetria em atmosfera controlada de 71,2 % N2 + 17,8 % O2 + 11% H2O, com temperatura constante em 650 °C e por um tempo de 240 minutos. O resultado da caracterização microestrutural permitiu identificar que, com o aumento do teor de cromo, houve aumento da fração volumétrica de carbonetos eutéticos e redução do espaçamento dendrítico secundário. Com as medidas de dureza da matriz após tratamento térmico verificou-se que, independentemente do teor de cromo, o pico de máxima dureza ocorre na temperatura de duplo revenimento de 550°C e, nessa temperatura, a amostra com 9% de cromo exibiu o maior valor de dureza. O ganho de massa das amostras submetidas ao ensaio de termogravimetria foi inversamente proporcional ao aumento de teor de cromo e todas as ligas apresentaram cinética de oxidação parabólica. A caracterização da seção transversal das amostras oxidadas, realizada por meio de um FIB, permitiu identificar, na amostra com 9% de cromo, uma nano camada de óxido de cromo, estrutura decisiva para a menor taxa de oxidação. Os resultados desse estudo permitem concluir que a variação do teor de cromo afeta de maneira significativa a resistência à oxidação, a dureza da matriz e a fração volumétrica de carbonetos eutéticos. / The effect of chromium variation, 3%, 6% and 9% Cr in mass in the microstructure, hardness and oxidation of a Multicomponent White Cast Iron was studied. The Thermo-Calc software version 5 was the tool used for thermodynamic calculations to predict the phases formed for each alloy. Experimentally, the following studies were carried out: i) microstructure characterization of the as cast alloys with the different chromium contents, ii) hardness test in the double tempered matrix at five different temperature between 400°C and 600° and iii) themogravimetric test with steam atmosphere composed of 71,2 % N2 + 17,8 % O2 + 11% H2O at constant temperature of 650° for 240 minutes. The result of the microstructure characterization allowed to observe that with increasing chromium content, there was an increase in the volume fraction of eutectic carbides and a reduction of the secondary dendritic spacing. Independently of the chromium content, a maximum hardness was observed always for double tempered at 550°C and the alloy with 9% of chromium exhibited the highest hardness average value. The final weight gain was inversely proportional to the increase in chromium content and all alloys showed parabolic oxidation kinetics. The alloy with 9% Cr showed the lowest final mass gain and the surface characterization of the sample after oxidation was carried out and the cross section of the sample was performed by FIB and was observed the formation of a nano-oxide layer on the alloy surface with 9% Cr. The results of this study leads to the conclusion that the chromium content variation significantly affects the oxidation resistance, the final hardness of the matrix and the volume fraction of eutectic carbides.

No description available.