dc.description |
A Thesis Submitted To The Department Of MECHANICAL AND
AUTOMOTIVE TECHNOLOGY EDUCATION, Faculty Of Technical
Education Of The School Of Graduate Studies, University Of Education,
Winneba, in partial fulfillment Of the requirements for the award of Master Of
Philosophy (Mechanical Engineering Technology) degree
BY
FRANK ABOAGYE KESSE
AUGUST, 2021 |
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dc.description.abstract |
One of the crucial industrial methods for joining metals has been welding, hence many
techniques have been developed to get an efficient and cost-effective process for
different kinds of materials. In this study, an attempt was made to investigate the tensile
and bending strength of A36 2.5 mm thick mild steel plate welded by the processes of
oxyacetylene and shielded metal arc welding (SMAW). The specimen, having been
carefully welded to form butt and lap joints were subjected to tensile and bending tests
using universal testing machine WAW-1000H. Four test runs were performed for each
welded joint. Based on the results obtained from the tensile and bending tests
conducted, it was observed that oxyacetylene welded joint produced a stronger joint
that could withstand much higher force compared with shielded metal arc welded joint
when lap and butt joints were considered. Where in oxyacetylene lap welded joint, an
average maximum ultimate tensile strength of 332.75 N/mm2 under an average force of
83.188 KN was obtained for four sample specimen, shielded metal arc lap welded joint,
recorded an average maximum ultimate tensile strength of 288.5 N/mm2 under an
average force of 72.125 KN. For butt joint, oxyacetylene recorded an average tensile
strength of 288.75 N/mm2 under an average load of 72.125 KN as against 256.75
N/mm2 under an average load of 64.163 KN for shielded metal arc welded joint.
However, in considering bending strength of oxyacetylene butt and lap welded joints
and shielded metal arc butt and lap welded joints where the joined workpiece might be
subjected to bending working conditions, shielded metal arc butt and lap joints recorded
bending strength of 6.0 N/mm2 under an average force of 0.6 KN and 6.50 N/mm2 under
an average force of 0.65 KN for butt and lap joints respectively as against 5.88 N/mm2
under an average load of 0.59 KN and 6.38 N/mm2 under an average load of 0.64 KN
for oxyacetylene welded butt and lap joints respectively. It is therefore recommended
to welding practitioners, engineers and fabricators that, for tensile strength, using 2.5
mm thick mild steel plate, oxyacetylene butt and lap welded joints should be used
compared to shielded metal arc butt and lap welded joints as the former could withstand
much higher tensile strength than than the later. However, for bending strength,
shielded metal arc butt and lap welded joints appears slightly beneficial than the other. |
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