Engineering Commons^™

Calorimetric Measurements On High Purity Iron And Eutectoid Steels, Marion Lewis Picklesimer

Doctoral Dissertations

Plan of the Investigation: The data needed to determine the thermodynamics of the transformation of a steel are: (1) the specific heat of austenite from above the critical temperature to the transformation temperature, (2) the specific heat of the transformed product from the reaction temperature to room temperature, (3) the enthalpy change at the transformation temperature, and (4) the variation of these with temperature of reaction.

Since the calorimeter could not be used to determine these data directly, that is, during the transformation of austenite to pearlite at temperatures well below the critical temperature, the problem was approached from the …

A Study Of The Bonding By Air-Setting Refractory Mortar At Elevated Temperatures, Bhikhubhai Mahadeo Sedalia

Doctoral Dissertations

"The importance of a suitable material for the laying of bricks in furnace and kiln construction has been recognized by the refractory industry for a long time. It is necessary that a strong bond should develop between the bricks to impart strength to the entire construction work. A weak joint would form the weakest link and dangerously weaken the whole structure.

Such being the importance of the bond, the refractory industry has made quite an effort to develop jointing materials which would produce strong bonds. During the last two decades, due to intensive research and development work, many good bonding …

A Study Of The Deformation Texture And Its Variation In Cold Drawn Nickel Rods, Krishan Kumar Tangri

Doctoral Dissertations

"The production of rods by cold drawing is a development of recent years as compared to other methods of fabrication. Though a good many investigations correlating the observed mechanical properties to the mill practices employed have been reported, the results nevertheless are more of a qualitative and empirical nature. It is well known that the physical properties of a metal product are related to its deformation textures which are characteristic of the metal and the fabricating method used. Thus a study of the deformation textures of cold-drawn rods, specially by x-ray diffraction techniques should provide a much more precise and …

The Rate Of Dissolution Of Aluminum In Hydrofluoric Acid, Yen-Ngen Wang

Doctoral Dissertations

"Pure aluminum has a relatively low strength, and its use is, therefore, rather limited. However, the resistance of pure aluminum to the attack of acids and many neutral solutions is higher than that of less pure aluminum or most of the aluminum-base alloys. For this reason, alclad alloy sheets, are made with a coating of pure aluminum on one or both sides of an aluminum alloy core. The coating is metallurgically bonded to the core over the entire area of contact. Thus the coating electrochemically protects the core from corrosive attack.

Aluminum is more negative in the electrochemical series than …

An Investigation Of The Characteristics Of High Alumina Refractory Castables, Gajendra Nath Mohanty

Doctoral Dissertations

"Refractory castables or concretes, a comparatively new member of the refractories family, are an admixture of highly aluminous cements and graded refractory aggregates, blended in predetermined proportions very much like structural concrete. The refractory aggregates must contain a large amount of fines contrary to the requirements of ordinary concrete. Unlike the Portland cements, which are mainly combinations of calcium silicates, the highly aluminous cements are predominantly calcium aluminates. They are comparatively of a refractory natures, having the hydraulic setting property combined also with high early strength. The discovery of the fact that these refractory concretes could be cast, in situ, …

Hydrogen Overvoltage On Titanium, Sheng-Tai Shih

Doctoral Dissertations

"The hydrogen overvoltage has been defined as the difference between the potential of the working electrode (cathode) and the theoretical reversible value for the same solution. This definition brings out the difficulty involved in the measurement of the "theoretical reversible potential for the same solution” as the potential of the hydrogen electrode in such a solution is usually different from the value of a standard reversible hydrogen electrode, for which the activity of hydrogen ions is set as being “1” and the potential arbitrarily set as being “0”. Besides, it is sometimes necessary to add addition agents to the solution …

Carbon Monoxide Attack Of Refractories, William A. Frad

Doctoral Dissertations

"The disintegration and failure of fire clay refractories due to the action of carbon monoxide has been studied tor a period at about fifty years. The most important application is in blast furnace refractories. Similar failures due to carbon deposition, involving other gases such as methane, have been noted and less extensively studied. Failures due to the action of gases other than carbon monoxide are beyond the scope of this thesis. Occasional attempts to find some agent to prevent disintegration have been mentioned in the literature. In this study the number of such substances and the results of their action …