A number of laboratory tests can be used to advantage to determine the behavior of metals in sea water. Controlled tests are especially useful in appraising the merits of new or modified alloys and in screening a number of compositions by tests on small specimens so that large scale trials required for final evaluation can be restricted to those alloys that show the most promise in laboratory tests.
Sodium chloride solutions offer certain advantages in laboratory testing but results obtained in many cases are not the same as would be obtained in the more complex natural sea water. The composition of a satisfactory synthetic sea water solution is given. Data are given to show the correlation between corrosion rates of copper alloy specimens in natural sea water and in synthetic sea water. Results of comparative spray tests using natural sea water and synthetic sea water also are reported (for cold rolled steel and zinc.)
The apparatus used in making simple immersion tests is pictured. The effects of high velocity and turbulence are discussed in detail and results of such tests are reported for a number of metals. Results of jet impingement tests are also given.
The apparatus used in making corrosion fatigue tests of metal specimens exposed to sea water is described. Other topics discussed include crevice corrosion, galvanic potentials and polarization, and cavitation erosion. 2.3.1