STUDENT INDUSTRIAL TRAINING (SIT)
CORROSION ENGINEERING (MCB 4423)
UTP CORROSION WEEK 2014
Project PresentationCorrosion Study of Outdoor Plant Hook
GROUP 5
GROUP MEMBERS
OUTLINE
Corrosion has been a major issue affecting public
infrastructure.This includes almost all structures, including this
outdoor plant hook situated at pocket D open garden, situated
beside block 16 and 15 in UTP campus.
PROJECT BACKGROUND
PLANT HOOK SPECIMEN
Made of mild steelOriginally intended for cheap decoration
substituteExposed towards open environment and weather changes,
with a small man-made stream nearbySince it became dull and
unappealing, it was removed from sight
PROBLEM STATEMENT
Corrosion of the hook makes it prone to break (at highest stress
concentration at hook curve), which might leads to unwanted
accident.Corrosion of the hook is not aesthetically appealing,
hence denting the landscape of the campus area.No corrosion
prevention eventually leads to the abandonment of the
infrastructure.
OBJECTIVE
Past Corrosion IncidentsAmong the highlighted case was in 1985,
where a concrete roof of a swimming pool collapsed only after
thirteen years of lifetime, killing 12 innocent lives. Post
analysis by the federal materials testing institute, based in
duebendorf, switzerland, and the federal materials research and
testing institute of berlin concluded that the collapse was the
result of chloride induced stress corrosion cracking (scc)[2].
LITERATURE REVIEW
9th May 1985, the concrete roof of public swimming pool collapse
only after 13 years of lifetime. 12 people got killed and 19 were
injured.
LITERATURE REVIEW
The steel rods had been pitted, causing the roof to cave in.The
collapse was result of stress-corrosion cracking.
LITERATURE REVIEW
LITERATURE REVIEW
The Uster incident can be avoided by:METHODOLOGY
SAMPLE PREPARATIONSOLUTION PREPARATIONWEIGHT LOST METHODLINEAR
POLARIZATION METHODEXPERIMENTAL SETUPELECTROCHEMICAL
MEASUREMENTELECTROCHEMICAL TESTCLEANING AND WEIGHT MEASUREMENTRATE
OF CORROSIONOBTAIN SAMPLE
METHODOLOGY
Linear Polarization (LPR) Method
RESULT AND DISCUSSION
At the beginning, the rate decrease drastically and slightly
uneven after 3 hours. Final corrosion rate of specimen in rainwater
is 0.13 mm/yr, in NaCl is 0.16mm/yrThe graph shows the result of
corrosion rate of NaCl and rain water within 24 hours.
Weight Loss Method
RESULT AND DISCUSSION
In each medium, the experiment is repeated with specimen B and D
for validation purpose.Cleaning cycles is repeated in order to
obtain constant final weight.
Table 2: Percentage of weight loss for each specimen Table 1:
Results of final weight after 336 hoursWeight Loss Method
RESULT AND DISCUSSION
Weight Loss Method
The corrosion rate of the specimens immersed in NaCl is higher
than in rainwater.The pH of NaCl is lower compared to the pH of
rainwater.The availability of hydrogen ions to react with electrons
at cathode also may influenced the rate of corrosion.
RESULT AND DISCUSSION
17CONCLUSION
The specimen is assessed by conducting Weight Loss Method and
LPR Method.The NaCl solution acts as baseline while rainwater as
actual medium.In both tests, the corrosion rate of the specimen in
baseline is higher that in rainwater.The difference of effects in
both condition is small and not very significant.The slight
difference might due to the simplicity of the measurement offered
by the weight loss method and thus may have slight error.
Experiment Accuracy:Make sure LPR technique is perform in
relatively clean aqueous solutionsNo water/oil emulsion in the
solution to prevent fouling of the electrodesCorrosion
Mitigation:Apply coating layer or galvanizationCorrosion
Prevention:Substitute plant hook material with a better alternative
(e.g. Iron)RECOMMENDATION
Q&A
