Metallurgy Commons^™

Viability Of A Proposed Transparent Fluid Model For Analog Metal Casting Filling Process, Andres Segura Irazoqui

Dissertations and Theses @ UNI

No abstract provided.

An Investigation Into The Prediction Of Double-Skin Penetration Within Chromite Molds And Cores In Heavy Section Steel Casting Using Process Simulation Software, Nathaniel Bryant

Dissertations and Theses @ UNI

This investigation was conducted in response to a commercial steel foundry approaching the University of Northern Iowa for assistance with a recurring defect they experienced on a production casting. The defect was described as a mass of metal that penetrated and consumed the interstices of their chromite molds and cores, and it was determined to consist of fayalite. After an extensive literature review, it was concluded that the foundry experienced the double-skin defect, a niche quality issue that most commonly occurs in heavy-section steel casting with chromite molding materials

After it was determined that the double-skin defect was occurring, a …

An Experimental Study Of Non-Metallic Inclusions Precipitation And Its Effect On Impact Toughness Variations In Low Alloy Steel Subjected To Complex Deoxidation, Pavel Bizyukov

Dissertations and Theses @ UNI

A low level of non-metallic inclusions in steel is the key requirement in the concept of clean steel. Although the concept has received its name quite recently, it has been implemented at the large-scale steel mills for more than 40 years. Production of clean steel became possible due active development and adoption of the post-melting treatment of molten metal in the teeming ladle. Ladle metallurgy, an umbrella term for various methods of treatment, includes operations that cannot be performed during primary metallurgical processes such as melting in an electric arc, basic oxygen, or air induction furnace. Initially, the most common …

Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner

Dissertations and Theses @ UNI

The problem addressed in this study is how contaminates in the foundry molding aggregate olivine, affect aluminum castings during the casting process. This research will concentrate on hydrated contaminates, specifically the mineral serpentine. The purpose of this research is to better understand how hydrated minerals contribute to the generation of pinhole porosity defects during the casting process. Understanding how impurities in foundry aggregates affect the casting process would aid in the reduction of scrap caused by core and molding sands, ultimately providing savings to the casting manufacturer.

A foundry grade olivine was compared to a new source of olivine to …

Preliminary Investigation Of Metallurgical Structure And Mechanical Properties Of Cast Iron With High Aluminum Content, Pavel Bizyukov

Dissertations and Theses @ UNI

The problem addressed in this study analyzed various properties of cast iron with high aluminum content. This grade of cast iron was projected for use in the automotive industry. The benefits provided with high aluminum content are lower specific gravity and relatively inexpensive source materials with the potential of achieving high temperature properties.

The purpose of the study was to select suitable source materials and determine an effective melting technique, to investigate metallurgical structure and mechanical properties at given chemical composition, and, finally, to provide elaborate results.

The design of the experiment included the following steps: (a) selection and preparation …

An Investigation Of Eddy Current Analysis For Laser Surface Treatment Of Steel, Ronald Edward O'Meara

Dissertations and Theses @ UNI

The problem of this exploratory study was to determine the strength of the bivariate correlational relationship between microhardness readings converted to Rockwell values and eddy current values of laser heat-treated AISI 1045 steel. Further, the microstructure was analyzed to determine the microstructural changes formed by laser surface treatment utilizing a carbon dioxide laser.

The purpose of this study was to investigate the microhardness and depth of hardness formed by laser surface treatment, to develop a measure of correlation between microhardness and eddy current values, and to study microstructural changes formed by the laser surface treatment. This knowledge could be used …

Pre-Inoculation Effect Of Sic In Production Of Thin Wall Ductile Iron Castings, Nikolay Y. Laukhin

Dissertations and Theses @ UNI

Pre-inoculation effect of SiC additions and its effect on castability, microstructure, and magnesium recovery in thin wall ductile iron plates have been studied. Experimental results were compared with alternative FeSi75 furnace pre-inoculation additions.

The first series of experiments aimed to set the baseline of iron quality, when using FeSi75 pre-inoculant

In the second series of experiment, different methods of introduction of Sic into liquid iron were studied. It was established that Sic added into the stream during the tapping into the flow-through chamber or added directly into the flow-through chamber produced lower Si recovery. The most effective method of introduction …

An Evaluation Of The Aws Entry Level Welder Training Program, John R. Rice

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the effectiveness of a training program for Entry Level Welders and to provide this information to the American Welding Society (AWS), industry, and educators. The problem of this study was to evaluate the AWS Entry Level Welder Training Program (ELWTP) by obtaining the opinions of faculty members who taught the program and welders who had completed the program.

Two groups comprised the research population for this study. The first group consisted of faculty members who were actually involved in teaching the course at institutions accredited by the AWS to offer the curriculum. …

The Effects Of Post Inoculant Additions On Ductile Iron Fade, Travis James Frush

Dissertations and Theses @ UNI

This study involved the investigation of three specific, commercially available, post inoculants for ductile iron and their effect on the magnesium fading rate and chill reducing tendency in a low volume production environment. Although fading effects of ductile iron have been extensively investigated, in general, they apply to high volume production operations. Unfortunately, for the smaller foundry operations, many of the process solutions proposed for the prevention of the fading effects are not applicable or practical. In addition to the small production operations, new process technologies are also excluded from many of these process solutions. For this reason, a study …

The Corrosive Effects Of Salt Spray On Electrolytic Zinc Plated Mechanical Fasteners: The Case Of Clear Chromate And Yellow Dichromate Coatings On Medium Carbon Plated Bolts, Souleymane Boukari

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the relationship between plating thickness and corrosion resistance of zinc coated medium carbon steel bolts under salt spray moisture conditions. Two types of zinc coatings were chosen for the study: the clear chromate zinc and the yellow dichromate zinc. One hundred and eighty 3/8-16 x 5 3/4 inch medium carbon steel bolts were selected for the test and divided into groups of 18. Two types of salt solution were used in the study: the low salt and the high salt. Bolts with various coatings tested with low salt concentration were composed of …

A Wear Analysis Study Of Selected Alternative Foundry Tooling Materials Using Impact Abrasion Testing, L. Fred Vondra

Dissertations and Theses @ UNI

The purpose of this study was to simulate the wear characteristics of foundry tooling using an impact abrasion test apparatus. The wear characteristic was exhibited by non-metallic materials and was measured as a function of percentage weight loss and was benchmarked against Class 30 gray iron. The research question focused on whether or not a non-metallic material exists that exhibits comparable or superior wear characteristics to Class 30 gray iron for possible consideration as tooling materials for foundry applications. The information obtained adds to knowledge and is useful to foundry professionals in making tooling decisions.

The 34 test materials were …

Development Of An Automated Ultrasonic Inspection Cell For Detecting Subsurface Discontinuities In Cast Iron, John Scott Burningham

Dissertations and Theses @ UNI

Manufacturing of value added products by companies in todays global marketplace requires the vendors to meet certain minimum standards, SAE, ASTM, ISO, etc. In a global economy, as a manufacturer for the year 2000 and beyond, preferred vendors will become ISO 9000 certified to maintain a market share of produced goods.

An automated inspection cell was developed for the inspection of cast iron ports to detect subsurface discontinuities. The cell consists of an ultrasonic flaw detector (UFD), transducer, robot, immersion tank, computer, and software. Normal beam pulse-echo ultrasonic nondestructive testing is performed on each rough casting.

Using test blocks and …

Surface Treatment Of Cast Iron By Adding Different Alloying Elements To Form Metallic Glass Structure Layer Using An Industrial Carbon Dioxide Laser, Mohammad Riahi

Dissertations and Theses @ UNI

Wear and corrosion are the two factors that make utilization of metals very costly. Extraordinary amount of time and money is spent to replace metallic parts affected by either wear or corrosion. Cast iron that is used very widely in a host of different industrial products is one such metal. Among the various methods used to improve the properties of metals, production of amorphous metals is highly noticeable. This process is done by treating the base metal in a certain technique which produces a metal that is more resistant to wear and corrosion.

This study was conducted to examine the …

Relationships Between Chemistry Variations And The Morphology And Nodular Formation Of Carbon Nodules In Ductile Cast Iron, Donald Francis Cassel

Dissertations and Theses @ UNI

The purpose of this study was to determine what relationships exist between the chemistry and the morphology and nodular formation of carbon nodules in commercially produced ductile cast iron. Additionally, the effects of chemistry on the hardness of produced castings from net shake processes were investigated. According to pertinent information in current literature, the hardness of castings has a direct bearing on the final cost of products.

The method of gathering this information and developing a correlation between the chemistry variations and the morphology and nodular formation was facilitated by the cooperation of a commercial producer of ductile cast iron …

Utilization Of A Carbon-Dioxide Laser To Form An Amorphous Metallic Layer On Gray Cast Iron With Various Amount Of Boron, Majid Torkzadeh Tabrizi

Dissertations and Theses @ UNI

The study of the amorphous metals in important because of their technological usefulness. One class of these materials, iron-based metallic glass, has shown great promise in application because of the superior chemical, mechanical, electrical, and magnetic properties of these materials.

This study was conducted to examine the capability of a medium-powered carbon-dioxide laser to form an amorphous metallic layer on the surface of a ferritic gray cast iron in order to improve the wear and corrosion resistance of engineered components. Boron was used as an alloying element for the retardation of nucleation and for the formation of the amorphous metallic …

Relationships Between Casting Features And Cavity Fill Time, Gate Velocity, And Gate Area For Aluminum Die Castings, Hsin-Yen Chen

Dissertations and Theses @ UNI

The purpose of this study was to investigate the relationships between casting features (including weight, average thickness, surface area, and outside diameter) and casting process variables (including cavity fill time, gate velocity, and gate area) for aluminum die castings. Historical data of good quality aluminum round castings of the Kiowa Corporation in Marshalltown, Iowa, were used in the correlation analysis. The correlation analysis consisted of determining the following:

(1) the correlation of one casting process variable and one casting feature.

(2) the multiple correlation of one casting process variable and a combination of several casting features.

The results of statistical …

The Effect Of Shielded Metal Arc Welding Process Variables On Delta Ferrite Control In Austenitic Stainless Steel Weld Metal, Ralph Eldon Long

Dissertations and Theses @ UNI

This study was to determine the effects of shielded metal arc welding on delta ferrite in austenitic stainless steel weld metal. The two objectives of the study were to determine: (a) what variables of the SMAW process affect the delta ferrite content or Ferrite Number of austenitic stainless steel weld metal, and (b) to what extent the Ferrite Number is affected by SMAW variables.

The research design was experimental with data collected from mechanically produced weld metal using a magnetic instrument calibrated in Ferrite Numbers (FN). The electrode alloys tested were 308, 308L, 316L and 347. The sizes of electrodes …