Stress-corrosion cracking (SCC) is observed in machine components when an optimal combination of stress levels and environmental
conditions is present in susceptible material. An interesting case history of intergranular SCC failure is presented in this
paper. This failure occurred in wear rings that were shrink-fitted on the impellers of a multistage horizontal feed pump during
the project procurement phase. After manufacture and assembly, two pumps were performance-tested in the supplier's test loop
for a combined total of approximately 600 h. The test duration lasted for approximately three months. During this duration,
the two pump internals were not absolutely dry and were exposed to an indoor environment in the supplier's test plant. After
the completion of the tests, the pump internals were inspected, cleaned, dried, and packaged before air freighting to the
reactor site. The pumps were in storage at the site for approximately two months. When the pumps were opened for inspection,
two wear rings on each of the pumps were cracked. This paper summarizes the results of the studies to evaluate the root cause
of the wear ring failures and the corrective actions implemented to avoid similar failures. 相似文献
Low temperature plasma (LTP) improves the shrink‐resistance of wool fabrics but impairs their softness, so different polysiloxane coatings were applied. Modifications in surface hydrophilicity and topography of fabrics and fibres have been recorded through drop test, contact angle and SEM, respectively. LTP improves the deposition of the polysiloxanes which, depending on their functionalities alter the original hydrophilicity of the wool surface. Softness and shrink‐resist results of the fabrics point out to a possible relationship between hydrophilicity of the wool fibre surface and the shrinkage behaviour of the fabrics. A possible mechanism of interaction between the different polysiloxane groups and the surface of untreated (UT) and LTP‐treated wool is proposed.
