A method for Comparative Studies of a Metal's Corrosion Resistance and apparatus as an Aid to these Investigations

摘要

1,161,980. Electro-physical measurement - corrosion resistance. G. RICHARDSON and B. ALGERS [trading as GRAB RICHARDSON and ALGERS]. July 15, 1968 [July 17, 1967], No. 33633/68. Heading G1N. A method of determining corrosion resistance comprises causing the corrosive fluid to flow-past a series of test-pieces at different velocities relative to each test-piece while they are electrically connected together. East test-piece is temporarily connected through an ammeter to the remainder and the "short-circuit" current is recorded to obtain a curve of current against time. The test-pieces may be bronze alloys formed as countersunk bolts mounted in a series of spirals 12a. . g; 13a. . g; 14a. . g, Fig. 2, on the insulating end-plate 3 of a housing 1, Fig. 1. A corrosive fluid e. g. seawater, is admitted centrally by a pipe 6 and distributed over the bolt heads by a rotor 10 driven by an electric motor 9, and leaves by an outlet 7. Holes with screw plugs (22, Fig. 4, not shown) may be provided up-stream from the testpieces to cause eddies for the study of cavitation corrosion. Abrasives may be added to the fluid. Alternatively the test-pieces may be mounted on the hull of a ship. Typical time/current curves are illustrated in Figs. (7..9).