A 2-dimensional model of a mill roll temperature distribution and radial thermal expansion is presented. The emphasis is on selective axial coolant distribution as a method of controlling strip profile. The Fourier equations describing heat conduction are solved using the method of finite differences. The following effects are considered: (i) The temperature distribution within the roll and strip just prior to entry to the roll bite. (ii) The heat generated in the strip due to deformation. (iii) The heat generated by friction between the strip and the roll. (iv) The temperature distribution of the strip and roll af ter each pass. (v) The heat conducted into the roll when in contact with the strip. (vi) The heat removed from the roll by the coolant, the air and the back-up rolls . The model also takes account of the geometry of the roll. This complexity means that different models for the roll and strip temperature distributions are required. The model evaluates individual heat transfer coefficients along the axis of the roll in order to simulate the effectiveness of each spray zone in removing heat from the roll. A simplified method of evaluating roll thermal cambers, derived from the model, is presented. The model shows good agreement between predicted and measured roll thermal cambers.The model is linked to a strip profile prediction model and used to investigate the effects of changing spray patterns and roll bend on profile. It was found that changing spray pattern has a significant effect on strip profile. It was concluded that: (i) Level spray patterns gave the best shape. (ii) Edge sprays sensitivity is important. (ii) over-cooling outside the strip provides good parabolic shape. ' (iv) A change to exit side, spray levels has a significant effect on strip profile. (v) Exit side sprays only has a tendency of rolling out the middle of the slab (i. e. a flat middle). (vi) All level sprays on the exit side of the roll only produce a distorted profile on the strip. It was also found that for any given change in roll thermal camber, there is a corresponding change in strip profile. The two changes can be related by a linear factor. The value of this factor has been investigated and found to be product and mill dependent.

Akademisk avhandling--Umeå, Sweden, 1958. / Extra t.p., with thesis statement, inserted. Includes bibliographical references (p. 105-[108]).

Akademisk avhandling--Umeå, Sweden, 1958. / Extra t.p., with thesis statement, inserted. Bibliography: p. 105-[108].

Bibliography: p. [i-iii]. / The service life of concrete in particularly extreme bacteriological environments has long been a problem that has been facing engineers and concrete materials experts. This is particularly relevant for the case of concrete sewer pipes, the useful life of which is critically limited by corrosion due primarily, and ultimately, to sulphide attack. Sulphides are formed from the sewage sulphates, by bacteria in the slime layers on the walls of the pipe. These diffuse, firstly into the liquid, and then into the sewer atmosphere as hydrogen sulphide, which is then in turn oxidised to sulphuric acid. Hydrogen sulphide gas is well known for its characteristic "rotten eggs" odour, but more important although less known, for its extreme toxicity. The maximum safe concentration in air is only twice that of hydrogen cyanide. It also has the dangerous side effect that the ability to sense it by smell is quickly lost after first encountering the gas, and deaths have occurred in sewers that can be both directly and indirectly attributed to hydrogen sulphide poisoning. The corrosion discussed in this thesis refers primarily to that caused by this bacteriologically created sulphuric acid attack in the space above the liquid, as opposed to sub-liquid level corrosion due to aggressive chemicals, more commonly associated with industrial effluents. This is all discussed more fully in later sections.

Thesis: Sc. D., Massachusetts Institute of Technology, Department of Metallurgy and Materials Science, 1973 / Vita. / Includes bibliographical references. / Sc. D. / Sc. D. Massachusetts Institute of Technology, Department of Metallurgy and Materials Science

Massachusetts Institute of Technology. Dept. of Metallurgy and Materials Science. Thesis. 1972. Ph.D. / MICROFICHE COPY ALSO AVAILABLE IN SCIENCE LIBRARY. / Vita. / Includes bibliographical references. / Ph.D.

Massachusetts Institute of Technology. Dept. of Metallurgy and Materials Science. Thesis. 1969. Ph.D. / Vita. / Bibliography: leaves 148-151. / Ph.D.

Massachusetts Institute of Technology. Dept. of Metallurgy and Materials Science. Thesis. 1971. Ph.D. / Vita. / Includes bibliographical references. / Ph.D.

Massachusetts Institute of Technology. Dept. of Metallurgy and Materials Science. Thesis. 1972. Ph.D. / MICROFICHE COPY ALSO AVAILABLE IN SCIENCE LIBRARY. / Vita. / Includes bibliographical references. / Ph.D.

Massachusetts Institute of Technology. Dept. of Metallurgy and Materials Science. Thesis. 1970. M.S. / Bibliography: leaves 25-26. / M.S.