Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1921. / The entire thesis text is included in file. Typescript. Illustrated by author, except for photographs. Title from title screen of thesis/dissertation PDF file (viewed May 29, 2009)

Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 73-90.

The aim of this thesis was to determine the impact of the used chemical composure during metallurgical treatment and foundry technology on the inner and surface quality of experimental casting under operational conditions at Třinec foundry. A minor part of this thesis is focused on the determination of the effect of filtration on mechanical properties of steel.

The aim of this thesis was to perform the classification of defects of emerging in a specific type of steel castings made by company UNEX Foundry, Ltd. and then determine the conditions of their origin. This is mainly discontinuity of casting material. The next step was to propose the corrective measures eliminating creation of these defects.

In its first part the work deals with the frequent defects of heavy steel castings. Experiments were carried out in very heavy bearing rings casting of cement kilns in order to reduce consumption of liquid metal and to increase the internal quality of castings. The progress was achieved by introducing new technologies; this thesis describes the technologies used and subsequently performs their comparison.

A massive castings defects are examined in this doctoral thesis, specialise in steels passing through peritectic transformation. There are typical types of defects at massive steel castings, as contrasted to „ordinary“ internal and surface ones. For massive steel castings are typical defects under feeders like conchoidal fractures, segregations, microporesities, reoxidation products. Combination of Al and Zr is an ordinary final deoxidation of EOP and LF steel for castings in ŽĎAS a.s. foundry. The aim of Al + Zr combination was to both deep deoxidation by Al (decrease of bubbles risk) and denitrification by Zr (decrease of conchoidal fractures). This theses refute premission mentioned above and verified persisting risk of defects under massive feeders, even though Al + Zr deoxidation is used. A final deoxidation by increased amount of Al was examinated, in combination with other deoxidation agents. Castings had 11 [cm] maximal modulus, and occurence of conchoidal fracture, reoxidation products and primary austenite grain size was evaluated. A selected optimal final deoxidations (Al, Al+Ti, Al+Zr) as a result from experiment described above, were evaluated on castings with 15 [cm] maximal modulus. The result of experiment is, that is not possible to repeatedly produce massive steel casting using EOP metallurgical equipment without defects under feeders, despite of deoxidation and pouring temperature optimalization. The defect indications look like conchoidal fracture, but there are microporesity and impurities instead. Finally, castings with maximal modulus 15 [cm] were produced using so called secondary metallurgy (LF, VD). Secondary metallurgy allowed to both significant decrease of sulfur and degassing of melted metal. Only this metallurgical procedure guarantees production of heavy steel castings without typical defects under massive feeders

In this study, it was shown that improvements in the quality of continuously cast steel billets, similar to those which can be achieved by electromagnetic stirring (EMS) of the liquid pool during solidification, can be obtained if casting superheats can be consistently controlled at low levels. A lack of casting temperature control is not only detrimental to the quality of the cast product, but also to a shop's overall productivity. The important variables for temperature control in the ladle, tundish and mould were quantified and possible methods of controlling these variables were proposed. / The thermal state of the ladle lining is one of the major contributors to the variability in casting temperature. It was shown that by reducing energy losses from the refractory ladle lining, by way of incorporating an insulating refractory tile between the ladle shell and the safety lining and by using a ladle lid throughout the cycle of the ladle, temperature losses from the liquid steel can be substantially decreased. (Abstract shortened by UMI.)

Diploma thesis deal with definnig the casuses of stell castings defects in the DSB EURO s.r.o Foundry. The main target is to optimise technological parameters for avoiding the surface casting defects. The first stage is the identification of the defects, describing of the main reasons and mechanic. Defect quantification is make from measuring of area and volume of the mended defects. In association with surface defects, the number of the crackings was observed. Finally there are suggested correction actions based on the previous investigation.

This diploma thesis resolves aplication of particular non-destructive testing methods while producing castings of steel wheels and quality control of this process. There are described fundamentals of flaw detection, determination of flaw-generation cause and suggestions for optimalization of casting process and increasing of its quality.

A massive castings defects are examined in this doctoral thesis, specialise in steels passing through peritectic transformation. There are typical types of defects at massive steel castings, as contrasted to „ordinary“ internal and surface ones. For massive steel castings are typical defects under feeders like conchoidal fractures, segregations, microporesities, reoxidation products. Combination of Al and Zr is an ordinary final deoxidation of EOP and LF steel for castings in ŽĎAS a.s. foundry. The aim of Al + Zr combination was to both deep deoxidation by Al (decrease of bubbles risk) and denitrification by Zr (decrease of conchoidal fractures). This theses refute premission mentioned above and verified persisting risk of defects under massive feeders, even though Al + Zr deoxidation is used. A final deoxidation by increased amount of Al was examinated, in combination with other deoxidation agents. Castings had 11 [cm] maximal modulus, and occurence of conchoidal fracture, reoxidation products and primary austenite grain size was evaluated. A selected optimal final deoxidations (Al, Al+Ti, Al+Zr) as a result from experiment described above, were evaluated on castings with 15 [cm] maximal modulus. The result of experiment is, that is not possible to repeatedly produce massive steel casting using EOP metallurgical equipment without defects under feeders, despite of deoxidation and pouring temperature optimalization. The defect indications look like conchoidal fracture, but there are microporesity and impurities instead. Finally, castings with maximal modulus 15 [cm] were produced using so called secondary metallurgy (LF, VD). Secondary metallurgy allowed to both significant decrease of sulfur and degassing of melted metal. Only this metallurgical procedure guarantees production of heavy steel castings without typical defects under massive feeders