1Department of Production Engineering, University of Benin, Benin City, Edo State, Nigeria.
2Department of Mechanical Engineering, University of Abuja, Nigeria.
Most of the coated steel electrode manufacturers in Nigeria have wound-up as a result of persisting problems like epileptic electric power supply, high cost of coating machines high production cost, and high product (coated electrode) cost. These issues have affected customers' demand and manufacturers' expectations adversely. Therefore, the need to design and manufacture a manually operated coating machine, that is simple in structure, reliable, easy to use and available for use at any time with very low or no maintenance and can produce, in approximate terms the same performance level with the automated imported coating machine, was conceived.
The manufactured coating machine was used to coat 3mm steel wires with four different flux formulations. The ultimate tensile strengths were found to be 570 MPa, 520 MPa, 580MPa and 510 MPa and the corresponding Brinell hardness numbers are 340, 310, 320 and 390 for fluxes 1, 2, 3 and 4 respectively. These values were compared with reported values in other literature and the coating machine was found to have performed comparatively well. Some welding experts with over ten years of professional experience were asked to give their earnest opinions on the welding performance based on administered questionnaires and the average of sample opinions gathered suggested that the simple coating machine was rated well. Generally the coating machine has a comparative coating performance when compared to the imported automated coating machine.The manually operated coating machine has very low speed and would need further improvement.
coating machine, die design, expert evaluation, flux composition, mechanical properties, welding performance
