Mechanical Behaviour and Microstructural Characterization of Carbon Steel Samples from Three Selected Steel Rolling Plants

The research investigated the mechanical behavior of samples of steel rods obtained from three selected Steel Rolling Companies in South Western part of Nigeria. This was done by carrying out some mechanical tests such as tensile, impact and hardness as well as microstructural examination.Four sets of 16 mm steel rod samples were collected from Tiger steel industries, Phoenix steel and Oxil steel Industies, all located in South West Nigeria, The chemical composition was carried out using a Spectrometer (EDX3600B). Afterwards, different samples were prepared, cut and machined according to ASTM standards dimensions of tensile and impact tests as well as hardness test from which their Ultimate tensile Strength, Yield strength, Percentage elongation, Impact strength and Brinell hardness number were obtained and compared to three standards (ASTM A706, BS 4449 and Nst 65-Mn). Their microstructures were also examined and analyzed.The results showed that the Ultimate tensile strength for the samples from Oxil steel, Phoenix Steel and Tiger steel were 661 N/(mm)2, 653 N/(mm)2 and 631 N/(mm)2 respectively while their hardness values were 150 BHN, 178 BHN, 214 BHN respectively. The sample from Tiger steel and Oxil Steel had the finest and most coarse microstructure respectively. In conclusion, it was observed that the results of the sample analysis from the three selected Steel Rolling Companies conformed to most of the standards except the sample from Tiger steel which had a high hardness value compared to the standard

Modeling heat flow across fuel-fired crucible furnace using ADINA

-The study simulated the heat flow across a fuel-fired crucible furnace using ADINA Software. Appropriate engineering materials were selected for the design and construction of the fuel fired crucible furnace. Among several parameters taken into consideration were strength/weight ratio, formability, cost and ability to fulfill specific service functions. Heat dissipation to the outside was minimal and this was clearly shown in the temperature gradient. Heat dissipation was uniform within the flame gap and inside the crucible pot. The Kaolin refractory material used showed very good insulation capacity significantly reduced heat losses. The modeled temperature distribution profile, heat flux and the temperature gradient were all in agreement with the validated results

Material Selection for Fuel Fired Crucible Furnace Using GRANTA

The study investigated the material selection for the fuel fired crucible furnace using bubble charts. The results were generated using GRANTA software. Different properties were considered during the selection of the materials for the furnace. The appropriate engineering materials were sought locally for the design and construction of the fuel fired crucible furnace. Among several parameters taken into consideration are strength/weight ratio, formability, cost and ability to fulfill specific service functions. All these were taken into consideration during the material selection process for the fuel-fired crucible furnace. These properties were plotted against each other in bubble chart and the selection of the appropriate candidate material was done on the bubble chart. The software plotted the properties of each unit of the furnace in form of bubbles and the candidate material where selected from the bulk of materials suggested by the software. The functions, objectives and constraints of the parts or the units to be designed were adequately specified and the material properties to be selected were determined based on these fundamental parameters

NUMERICAL SIMULATION OF OUTER DIE ANGLE OF EQUAL CHANNEL ANGULAR EXTRUSION PROCESS

The study of the simulation of effect of outer die angle in Equal Channel Angular Extrusion (ECAE) process was investigated. The simulation was carried out on 6063 aluminium alloy with a view to achieve ultra-fine grain structures. ADINA user interphase Version 8.6 (900 modes) was used for the simulation. The unextruded parameters of the 6063 aluminium alloy were used as input codes and some basic assumptions were made in designing the model on 2-Dimensional scale. The billet was meshed by dividing the vertical and horizontal geometry into 30 and 4 elements respectively. The die angle was varied from 0o to 90o and the simulation results were displayed. The results showed that the force of 27.5X106 N, 27.5X106 N, 27.6X106 N and 31.2 X106 N was required to deform when the outer die angle was 0o , 22.5o , 45o and 90o respectively. Also, the strains achieved were 0.61, 0.62, 0.66 and 0.69 respectively. Thus, highest force is required at 90o and the strain achieved at 0o is the lowest. Based on the results, it was recommended that it is more economical to extrude at an outer angle between 22.5o and 45o as a relatively higher effective strain will be induced

Corrosive Effect of Pineapple Juice on the Fatigue and Hardness Properties of Austempered Ductile Iron

The work investigated the corrosive effect of pineapple juice on the fatigue and hardness properties of austempered ductile iron in a stagnant fluid environment. The test data and the related material constants were used in the fatigue life prediction analysis to aid in the design of components made from ductile iron. Eighteen specimen were divided into three groups and were labelled A1,2,3,4,5,6 , B1,2,3,4,5,6 and C1,2,3,4,5,6. They were subjected to the corrosive medium and each group were removed from the medium at an interval of two weeks respectively. Fatigue and hardness tests were conducted on the samples as well as on control samples D1,2,3,4,5,6 at different corrosion levels. The results obtained showed that ductile iron corroded in pineapple juice and the fatigue strength reduced with increasing retention of samples in corrosive environment until there was no defined fatigue limit at the end of six weeks in the corrosive fluid. Hardness property was not significantly affected in pineapple juice environment. pH progressively went more acidic in the course of corrosion

Microstructural Characterization and Some Mechanical Behaviour of Low Manganese Austempered Ferritic Ductile Iron

This work studied the microstructural characterization and mechanical behavior of low manganese Austempered Ductile Iron (ADI), with a view to improve the properties of iron and to increase the areas of applications. Three sets of ductile iron of specified composition were machined from Y-blocks to tensile and hardness pieces. The samples were preheated at 350 0C for 1hr and austenitised at 900 0C for 1hr in salt bath furnace. The three sets of samples were immediately austempered in the austempering salt bath furnace at uniform austempering temperatures of 300 0C, 350 0C and 400 0C for 90, 120 and 150 minutes; each sample for each temperature window. All sets were prepared for metallographic examination; tensile and hardness tests were carried out. The results showed that maximum hardness, tensile and yield strength were obtained at austempering temperature of 350 0C and at 150 minutes. At 300 0C and 350 0C, it was noticed that the hardness and strength increase with austempering time. The optimum tensile strength was 1300 MPa at 350 0C after austempering for 150 minutes. In conclusion the austempering operation has a significant effect on the mechanical and microstructural properties of ADI

NUMERICAL SIMULATION OF OUTER DIE ANGLE OF EQUAL CHANNEL ANGULAR EXTRUSION PROCESS

The study of the simulation of effect of outer die angle in Equal Channel Angular Extrusion (ECAE) process was investigated. The simulation was carried out on 6063 aluminium alloy with a view to achieve ultra-fine grain structures. ADINA user interphase Version 8.6 (900 modes) was used for the simulation. The unextruded parameters of the 6063 aluminium alloy were used as input codes and some basic assumptions were made in designing the model on 2-Dimensional scale. The billet was meshed by dividing the vertical and horizontal geometry into 30 and 4 elements respectively. The die angle was varied from 0o to 90o and the simulation results were displayed. The results showed that the force of 27.5X106 N, 27.5X106 N, 27.6X106 N and 31.2 X106 N was required to deform when the outer die angle was 0o, 22.5o, 45o and 90o respectively. Also, the strains achieved were 0.61, 0.62, 0.66 and 0.69 respectively. Thus, highest force is required at 90o and the strain achieved at 0o is the lowest. Based on the results, it was recommended that it is more economical to extrude at an outer angle between 22.5o and 45o as a relatively higher effective strain will be induced

Performance Evaluation of Suitability of Carbonized Palm Kernel Shell (PKS) as a Veritable Alternative to Coal and Charcoal in Solid Fuel Fired Furnaces

PKS were carbonised in other to drive off the organic matter, and obtained a clean solid fuel. Leco 350 Bomb Calorimeter was used to determine the heating value of the fuel; while adiabatic flame temperature and mass of air/ Kg of fuel were calculated for different conditions of excess air ratio ‘n’. The carbonised PKS was used to melt aluminium. Results: The higher heating value of PKS was 26541.204KJ/Kg. The lower heating value of PKS was 24457.9592KJ/Kg. The adiabatic flame temperature at n = 1 and 1.3 were 2082°C and 1679°C respectively. The air/fuel ratio is directly proportional to n. Discussion: The higher heating value of carbonised PKS was comparatively higher than those of firewood, peat and lignin but less than bituminous and anthracite coals

The Thermal Analysis of Fuel Fired Crucible Furnace Using Autodesk Inventor Simulation Software

The reasons for failure of locally made furnace in the foundries were as a result of cycles of operating temperatures that they were subjected to, which caused thermal stress and strain on the furnaces. This paper studied the simulation of thermal analysis of Fuel fired Crucible Furnace to predict the effect of thermal stress and strain on it

Material Selection for Gas Turbine Blade Coating Using GRANTA Material Selector

This paper presents the selection of suitable candidate materials for thermal barrier coating of gas turbine blade using GRANTA software. There have been reported cases of gas turbine blade failure in service due to the extreme service conditions. Such failure could possibly have occurred due to poor material selection for thermal barrier coatings on the turbine blade thereby exposing the blade to harsh condition over time. The major adverse effects on these blades are thermal fatigue, high temperature oxidation, hot corrosion, interdiffusion, high cycle fatigue and creep