ELECTROCHEMICAL BEHAVIOUR OF Al-BRASS IN SEAWATER
Corrosion of the Al-brass in 3.5 % NaCl solution and natural seawater was investigated with potentiodynamic polarization technique. Corrosion rate obtained in natural seawater was higher than in 3.56 % NaCl solution. The metallographic examinations indicated the occurrence of pitting corrosion in both cases.
Impingement Corrosion of Condenser Tubes
AbstractThe problems of impingement corrosion of condenser tube materials are reviewed, with special reference to the power industry of the UK. The South Eastern Region of the Central Electricity Generating Board has set up a laboratory to study the corrosion behaviour inflowing sea water of metals used in power station cooling water systems. The jet impingement facilities of the laboratory are described and the results of recent work presented. These include the impingement characteristics of some standard condenser tube materials, the modification of these characteristics by such methods as cathodic protection and ferrous sulphate dosing of the sea water, and the resistance to impingement corrosion of some new materials. Particular attention is paid to titanium and its resistance to this form of corrosion.
Experimental investigation of the geotechnical properties and microstructure of lime-stabilized saline soils under freeze-thaw cycling
Abstract The Song-Nen Plain in northeastern China holds one of the three largest expanses of soda saline-alkali soil in the world. Due to its disadvantageous geotechnical properties, the saline soil in this area is unable to meet the needs of construction projects. This study evaluates the stabilizing effect of adding lime to such soils. Specifically, it investigates how the physicochemical and mechanical properties and microstructure of soda saline-alkali soil are altered by lime and how these changes are affected by both freeze-thaw cycling and the duration of curing. The results reveal that adding lime to saline soil transforms clay particles into sand and silt particles and causes the pore size distribution (PSD) to become bimodal, with small-pore and macropore populations. An increase in lime content leads to an increase in the unconfined compressive strength (UCS) but a gradual decrease in both the cation exchange capacity (CEC) and plastic index. Freeze-thaw cycles break up coarse particles and aggregate finer particles, increasing the diameter of macropores and decreasing the USC; however, the effect on specimens with >9% lime is negligible. It is further shown that the geotechnical properties of the soil change immediately after the addition of lime, indicating that the cation exchange reaction takes place very quickly. Furthermore, the pozzolanic reaction leads to an increase in the percentage of sand-sized particles and a decrease in porosity after 28 days of curing. Overall, these results indicate that it is feasible to use lime to improve the engineering properties of soda saline-alkali soil in this area.