|
|
| |
| Articles
by
J.T. Stephen |
Total Records (
3 ) for
J.T. Stephen |
|
 |
| |
|
| |
J.T. Stephen
,
A.J. Alawode
and
O.I. Oluwole
|
| |
The effects of heat treatment on corrosion rates of pipe weldments and pipe-whip restraint devices in saltwater medium were investigated and presented. Mild steel pipes were preheated within temperature range of 30-200°C before respective circumferential welding of single-, double- and triple-passes. Thereafter, pipe weldment zones of 10 mm width were cut out and immersed in saltwater. The corrosion rate of single-pass weldment of as-received pipe immersed in saltwater for 90 days was found to decrease by 8.47 and 20.0% due to pipe preheat at 100 and 200°C, respectively. Also, the corrosion rates of double-pass and triple-pass weldments of as-received pipes were correspondingly higher than the 6.85 mpy value for single-pass weldment of identical as-received by 3.21 and 6.57%. This shows that corrosion rate decreases with increase in pipe preheat temperatures but increases with increase in welding pass. Though, weight loss increases with increase in immersion time, corrosion rate does not follow the same trend due to the concentration of stagnant ions blocking the creation of more ions and thus reducing Fe2+ activities in the solution. Corrosion rate of U-bar specimens was also found to decrease with increase in immersion time and with increase in tempering temperature. The findings of this research work shows that appropriate heat treatment could be used to minimize the corrosion rates of metallic structures in a corrosive medium. |
|
| |
|
| |
A.J. Alawode
,
J.T. Stephen
and
G.J. Adeyemi
|
| |
Environmental pollution is a major adverse consequence of the rapid urban growth, increased economic activities and industrial development witnessed globally and particularly in Nigeria for the past few years. Various forms of pollution pose threat to the health and safety of mankind and its environment. This study, therefore, carries out an assessment of the health, safety and environmental issues in Nigerian manufacturing and processing industries with a view to re-awakening and re-sensitizing environmentally conscious industrial activities and municipal waste disposal attitudes towards a safe and healthy environment. Diverse forms of occupational hazards, air and water pollution and waste management and disposal challenges are discussed and the health, safety and environmental attitudes of Nigerian industries, municipalities and the public in general are reviewed. Workers in many Nigerian companies are exposed to a lot of occupational hazards and our air and water pollution control and waste management and disposal systems need to be improved to comply with international standards. Suggestions are therefore made towards an improved health and safety status of the environment by recommending industrial health, safety and environmental policies for Nigerian companies. Measures of minimizing occupational hazards and ways of actualizing efficient and effective industrial waste management and disposal systems are also recommended. |
|
|
| |
|
| |
A. Adebayo
and
J.T. Stephen
|
| |
This research presents the effects of heat treatments on the mechanical properties of `mild steel. Sample of mild steel rods were subjected to the following heat treatment. Sample of these specimens were annealed at temperature of 100, 300 and 500°C while others were heated to 900°C and quenched in SAE 40 oil. Some of these specimens were retained as-quenched while others were tempered at temperature of 200, 400 and 600°C. The heat treated mild steel rod were then subjected to tensile, impact and torsional test the results of these tests show that stress and ultimate decreases as both annealing and tempering temperature increases. Also the percentage elongation increases as the annealing and tempering temperature increases. Moreover, the impact energy and the breaking torque increases as the tempering and the annealing temperature increases. |
|
|
|
|
| |
|
