Yu. M. Panchenko

Atmospheric corrosion of metals in regions of cold and extremely cold climate (a review)

The results of atmospheric corrosion tests on a series of metals and alloys in marine and industrial atmospheres of the Earth’s regions with cold and very cold climate (Antarctic, sub-Arctic, Russian Far East) are considered. The class of most dangerous corrosive damage includes special types such as pitting, exfoliation corrosion, crevice corrosion and corrosion-induced cracking. Long-term prognosis is made concerning the influence of global warming on the atmospheric corrosion in cold climate regions.

Comparative estimation of long-term predictions of corrosion losses for carbon steel and zinc using various models for the Russian territory

ABSTRACT Based on the results of 1-year tests at 12 sites in the Far Eastern region of Russia, priority dose–response functions (DRFs) that provide the best match with experimental data on corrosion losses for carbon steel and zinc have been selected. Long-term (up to 50 years) predictions of corrosion losses of these metals in the continental territory of Russia have been given. A comparative estimation of the mass loss predictions by priority DRFs and the power–linear model has also been given.

Corrosion Resistance of D16 Alloy Depending on the Salinity and Meteorological Parameters of Coastal Atmosphere

Results of two-year-long atmospheric corrosion tests of D16 alloy in representative coastal regions under natural field conditions and during artificial sedimentation of sea sal that corresponded to a salinity range of 0–300 mg Cl−/(m2 day) are discussed.

Atmospheric corrosion in tropical and subtropical climate zones: 3. Modeling corrosion and dose-response function for structural metals

The results of statistical analysis of a corrosion-climate database are presented. New dose-response functions have been obtained by methods of multiple and nonlinear analysis for evaluating corrosion-related weight losses of structural metals in the regions with humid tropical and subtropical climate.

On Calculating the Mean Corrosion Resistance and Total Thinning of Flat and Wire Metal Samples for Determining Atmospheric Corrosivity

Possible calculation errors are discussed as regards the environmental corrosivity monitoring based on the outdoor exposure and evaluation of the corrosion penetration rate of helical wire samples according to the ISO 9223 and 9226 International Standards.

Calculating Corrosion Parameters of Sheet and Wire (Helical) Samples when Classifying Atmospheric Corrosivity

The report deals with mathematical expressions derived for the purpose of calculating atmospheric corrosion rates, including those of changes in total weights and weights of corrosion products retained at the surface of flat sheets and wire helices used as samples in monitoring the corrosivity of the environment according to the International Standards ISO 9223 and ISO 9226.

Formation, retention, and discharge of products of atmospheric corrosion of metals. 4. Model: Corrosion-discharge of products

An empirical mathematical model K = K0 + kmlos (relating atmospheric corrosion to the weight loss of its products) for incubation + transient and steady-state stages of the process, is considered. To develop the model, we used the results of long-term (from 3 month to 1–17 years) field tests of metals according to the Russian, International ISOCORRAG, and Russia-Vietnam-Cuba programs. The K0 and k factors in the model were determined according to the corrosion of Ct3, copper, brass, zinc, aluminum, Δ16 alloy, and AMц alloy in the zones of cold, moderate, subtropical, and tropical climates. The model quantitatively relates the corrosion losses of a metal to those of the products discharged to the environment. It may be useful when it is necessary to estimating the amount of detrimental metals, e.g., unprotected copper and zinc dispersed to the environment, but there is no data on the weight of products that had been retained by the metal in the air.

Formation, retention, and waste of products of the atmospheric corrosion of metals. 3. Corrosion losses and the weight of retained products

The dependence m/K = f(K) (m is the weight of retained products per the unit weight of corrosion losses) on the integral weight of corrosion losses K, which is observed for zinc, carbon steel, copper, brass, aluminum, as well as Д16 and AMд alloys, in cold, temperate, and tropical cimates, is analyzed. Two groups of empirical equations are proposed to express the functional dependence m/K = f(K). The weight of retained products of outdoor corrosion on zinc, steel, aluminum, and copper, which was calculated from these equations, adequately agree with the experimental weights of products after 1-year outdoor tests of these metals carried out since the late 50s of the past century in Russia and China.

Comparative Assessment of Zinc and Cadmium Electroplates by the Weight of Retained Corrosion Products and the Total Weight

The correlation between the corrosion weight losses, the weight of retained corrosion products, and the total weight–change of steel specimen, which has a plain or superficially converted zinc or cadmium electroplate 24 μm thick, is studied. The specimens measuring 50 × 70 × 2 and 100 × 150 × 2 mm were exposed for 1 to 5 years in the open and semienclosed atmosphere in coastal and continental test stations and for up to 20 years in the enclosed atmosphere on coasts. The retained product weight and the total specimen weight gain (or loss) vary linearly with the corrosion metal weight loss (K= a+ bX) both in low- and high-corrosive atmospheres. Cadmium coatings retain a lower amount of products than zinc ones, while superficially converted ones retain lower amount than plain ones. The largest amount of products is retained in enclosed atmosphere. In semienclosed and open atmospheres, the amounts are smaller by factors of approximately 1.5 and 2–4, respectively. Knowing the coefficients of a corresponding linear equation and the weight of retained products of zinc or cadmium corrosion on specimens (in a certain time), one can calculate the corrosion rate of a coating in each atmosphere. For a predicted corrosion of ≤50 g/m2 , the estimation error will not exceed ±20–30%.

Marine Corrosion Tests of Galvanic Coatings for Ship Instruments. XI. Gold and Palladium Coatings on Brass

The corrosion peculiarities and the protective and decorative characteristics of gold and palladium coatings were investigated in containers simulating the casings for ships equipment of watertight and splashproof types. The coatings (3 and 6 μm thick) were applied to 62 brass specimens either directly or with a 12 μm-thick silver sublayer (Ag12/Au3, Ag12/Pd 2, μm). The specimens plated were tested by exposure for 14–20 years at coastal corrosion stations in cold (Murmansk), moderately humid (Vladivostok), and humid subtropical (Batumi) climates. The dezincification products of the brass substrate emerging through the pores of the coating form stains and salt films on its surface. Clogging the pores, the products become responsible for the blistering of the plate. The corrosion weight loss linearly correlate with the surface accumulation of chlorides; the thicker the coating, the smaller the damaged area of the substrate, but the deeper the corrosion centers. The technical service life of protective coatings is refined.