bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Thin Metal Film Corrosion Indicators
Authors: ROLLER DAVID , ROHRBACK G. H.
Published: February 2013

An account is given of the development of visual and electrical corrosion indicators which utilize thin metal films vacuum-deposited on non-metallic substrates. Data are presented showing the behavior of these indicators in corrosive atmospheres. Although the indicators were developed primarily to detect and mark corrosive conditions in packages and storage areas, other possible applications are described briefly. Data reported include comparative corrosion information on electrical cards and buttons in various humid atmospheres, condition of visual and resistance thin film indicators at first sign of corrosion on hardware items, and behavior of polyvinyl resistance card indicators at different sensitizations at 25 C and 60 percent relative humidity.

The paper presents the progress of this development program from the feasibility studies through the final development of manufacturing protypes. 3.23
Engineering and Design Problems Affecting Cathodic Protection of Lacq Field Well Casings
Authors: Estavoyer M.
Published: February 2013

Potential profiles taken of 95/8 inch gas well casing at the Lacq Field in south-western France were evaluated to determine the correlation between current discharge zones and geological formations. At the same time an effort was made to distinguish between galvanic currents and stray current originating from an electric railway traversing the field. Estimates of the general electrical conformation of the field were deduced from data collected on a few wells.

Numerous conventional methods were considered in attempting to fix the optimum current density to be applied to each casing. Cathodic protection currents varied in volume from 15 to 50 amperes, so ground beds of varying configurations were used, including 50 meters of pipe horizontally in a conductive zone and 50-meter vertical holes.

An investigation is under way to determine what benefits can be obtained by altering, the existing, electrical configuration resulting from the electric railway stray currents. This will be accomplished by modifications at a substation and possibly by using the pipe-line grid as a low-resistance drainage return. There is some concern that cathodic protection may produce local cells whose effect seems to be as severe as the galvanic currents normally existing. 5.2.4
Suggested Methods and Practices for Cathodic Protection Coordination
Authors: Jones David T.
Published: February 2013

Discusses methods and practices used by a telephone company to coordinate its cathodic protection activities with other operators and owners of buried metallic substructures. This coordination is done to minimize effect of cathodic protection on metallic substructures. 5.2.1
Materials Problems Associated With Uncooled Rocket Nozzles
Authors: WALTON JESSE D. , MASON C. R.
Published: February 2013

A brief discussion is given of thermal shock, erosion, and catastrophic corrosion problems connected with uncooled rocket nozzles used with solid fuels. This is followed by a description of materials and methods used to meet these problems. A small oxygen-hydrogen rocket motor was used to screen materials.

Slip cast fused silica was used as a base material and erosion and corrosion resistance was provided in the throat area with arc-sprayed coatings or shells. Fabrication and evaluation techniques used are described as are forming methods and test results. 7.2
Ablation Behavior of Materials Subjected To Missile Re-Entry Heat Flux Rates
Authors: KRUPKA R. M. , TAYLOR D. E.
Published: February 2013

Hypersonic vehicles, during re-entry, are exposed to transient heating involving extremely high heat flux rates. These heat flux rates have been simulated in the laboratory with the plasma discharge from high-intensity, air-stabilized electric arcs of approximately 1000-kw power rating. This paper describes the behavior of samples of ten different materials tested in this facility, including four metals, three ceramics, two plastics, and graphite. Ablation rates, heat balances, and effective heats of ablation are presented. The influence of changes in the test environment upon material behavior is indicated. In the highest temperature test environment utilized, the plastic and graphite samples provided lower stagnation point weight loss rates during ablation than the metal and ceramic samples. 3.5.9
Inhibition of Corrosion of Commercial Aluminum In Alkaline Solutions
Authors: SUNDARARAJAN J. , RAMA CHAR T. L.
Published: February 2013

The corrosion rates for commercial aluminum, containing 4 percent manganese and 3 percent iron, have been determined in sodium hydroxide solutions under different conditions. The inhibitor efficiencies have been calculated for the following substances, the efficiency decreasing from 90 to 60 percent in the order: agar-agar, gum-acaciae, dextrin, gelatin, glue. Corrosion potentials have been measured with and without dextrin inhibitor, and cathodic and anodic polarization studies made. The results show that the dissolution of the metal is electrochemical in character. The corrosion process appears to be under mixed control with predominance of action of dextrin inhibitor on the anodic areas of the metal surface. 6.4.2, 4.3.3, 5.8.2
Methods and Experience in Underground Cathodic Protection
Authors: HENDERSON OLIVER
Published: February 2013

An account is given of various methods used by a telephone company to minimize the corrosion of lead sheathed underground communication cables. Controlled drainage connections were established into all d-c railway substations, forced drainage systems set up to overcome end effects and use made of rectifiers, magnesium anodes and magnesium ribbon to overcome anodic conditions.

Utility structures were consistently isolated from each other. Insulation joints were used at building entrances, resistance bonds were avoided at pipe line crossings and insulators used in anchor guys. But the advantages of isolation will soon need re-consideration in view of the growing tendency to interconnect telephone cable sheaths and power company multi-grounded neutral system. 5.2.1, 7.7, 8.2.1
Corrosion Measuring Probes for Marine Applications
Authors: ROLLER DAVID , SCOTT WILLARD R. , PREISER HERMAN S. , COOK FRANK E.
Published: February 2013

This paper describes the design, fabrication and preliminary testing of several types of corrosion measuring probes developed for use on maritime vessels. The probes are part of a system utilizing the electrical resistance method for continuously monitoring corrosion during actual operation. One type of probe to be described is intended for monitoring corrosion on either the exterior surface of the hull or interior structural members in large compartment. Another probe has been developed for measuring condenser tube inlet (tube end) corrosion. A third probe has been developed for measuring corrosion in crevices and pipe lines. Both laboratory and simulated service testing has been carried out. Results of these tests and the effectiveness of the probes in measuring corrosive conditions on ships are discussed. 2.4.2
Leakage Conductance Coating Surveys On Asphalt Mastic Coated Pipe
Authors: PAISLEY GERALD J.
Published: February 2013

Follow-up leakage conductance surveys were made at ten-mile intervals along 335 miles of continuous asphalt mastic coated pipe. Check points included three major river crossings. Test results were compared with data reported earlier on the same pipe by D. E. Miltner (see Corrosion, 9, 210 (1953) July). It was found that the overall current requirements of the 335 miles of six-inch pipe line had not increased in 18½ years. A total current of 18 amperes over-protected the line to a minimum protective potential of 1.000 volt. Progressive deterioration of the coating as a whole was not evident although there was considerable deterioration in the immediate vicinity of coating discontinuities. The low mean average coating conductance reported indicated that cathodic protection had not adversely affected sound coatings during the 18½ year interval.

4.5.3, 5.4.10
Laboratory and Field Tests on Titanium for Oil Field Pump and Valve Parts
Authors: Jessen F. W. , Molina Ricardo J.
Published: February 2013

Laboratory and field tests are reported for titanium parts for gas lift valves and down-hole oil well pumps. While titanium performed well in the laboratory tests using aerated fluids, and did well in field tests of gas lift wells, similar trials in wells pumping sour crude oil well showed titanium to be inferior to normally used materials. Authors conclude titanium is suitable for use in gas lift valves and could be competitive to presently used materials at a lower price.

They conclude titanium is not suitable for use in oil well pumps, but might perform better if hardened. It also is at a competitive disadvantage to commonly used materials costwise.

While titanium is cathodic to materials commonly used in oil wells, no marked corrosion was attributed to this property after exposure of coupon sets in a producing well. Titanium was found resistant to abrasion by sand-laden aerated oil well fluids in laboratory tests.

6.3.15, 8.4.3
Economics of Chemical Plant Maintenance Pointing
Authors:   A Report of NACE Technical Unit Committee T-6D On Industrial Maintenance Painting; Prepared by Task Group T-6D-1 on Economics of Maintenance Painting
Published: February 2013

Replies from a questionnaire indicate that the cost of industrial maintenance painting is increasing and that labor-to-material costs are in a ratio of 3 to 1. Data also are given on parameters by which the average cost of maintenance painting in six industrial categories may be estimated. Field testing is the most popular method of selecting a paint and the applied cost of systems based on sandblasted surfaces is noticeably higher than for systems on hand-cleaned surfaces.

Appearance was the most frequently mentioned reason for repainting, with avail ability of a budget next in significance. The concensus was that intervals for re painting indoors or out should be about four years. Engineers think improved paint ing practices have saved their companies about 26 percent of total painting costs.

1.2.2, 5.4.5
Corrosion Inhibitors for Hot-Carbonate Systems
Authors: BIENSTOCK D. , FIELD J. H.
Published: February 2013

The evaluation of the effectiveness of various inhibitors on the corrosion of steel in boiling solutions of potassium carbonate saturated with carbon dioxide and hydrogen sulfide is cited. The corrosion of carbon steel in a carbonate solution saturated with carbon dioxide can be eliminated with a 0.2 percent concentration of either potassium chromate or sodium metavanadate. In solutions of carbonate saturated with carbon dioxide and hydrogen sulfide no corrosion is obtained with 0.2 percent sodium metavanadate or 0.15 percent vanadium pentoxide. The alkaline-sulfide mixture destroys oxidizing inhibitors such as potassium chroma te. N-alkyl trimethylene diamines at a concentration of 0.1 percent reduce the corrosion rate to about 5 mpy. Sodium metasilicate, at a concentration of 0.6 percent, completely inhibits the corrosion, but deposits free silica in the system. Commercially available cladding materials such as the epoxy-coatings also prevent corrosion.

5.8.2, 6.2.3
Corrosion Control Advantages of Polyamide-Epoxy Coatings
Authors: Anderson Donald L. , Floyd Don E. , Glaser David W. , Wittcoff Harold
Published: February 2013

Chemical and physical properties of polyamide resins are described. Resistance of General Mills' polyamide resins to various acidic and alkaline corrosives in both static and dynamic tests are compared to those achieved with commercial inhibitors. Results of tests in a semi-tropical ocean environment of 17 primer types consisting of various combinations and percentages of polyamide-epoxy vehicle with zinc, chrome and lead pigments; alkyds, phenolics, vinyls, poly-vinylchlorides and a linseed oil vehicle are given. These tests of angle irons and flat panels up to 24 months showed polyamide-epoxy systems (with or without corrosion inhibiting pigments) to be better than others, even when brushed onto wet, rusty surfaces.

Wetting ability, adhesion and flexibility of the polyamide-epoxy systems as registered in several tests are reported. Also given are rate of transmission of water and water vapor.

Data are provided on formulations and application techniques. These include sand-filled coating, solventless finishes (with tests versus several corrosives and solvents). Also given are descriptions of applications as pipe coatings, marine submersion service, for aircraft and concrete. 19 references.

6.8, 5.4.5
Reaction of Zirconium With Carbon Dioxide at 550–750 C
Authors: GREGG S. J. , HUSSEY R. J. , JEPSON W. B.
Published: February 2013

The kinetics of the oxidation of zirconium in Carbon-14 labelled carbon dioxide have been investigated at 550, 650 and 750 C with the vacuum microbalance. The amount of carbon deposited on the sample surface during oxidation in carbon dioxide was only about 2 percent of the total weight gain at each of the temperatures. In carbon dioxide, the rate of oxidation first decreased and then increased with time indicating breakaway. In runs in oxygen (carried out for comparative purposes), the rate continuously decreased with time and breakaway did not occur within the period of the experiments. Maximum weight gain was 900 μg/cm2.

6.3.20, 3.4.6
A Study of Scaling and Corrosion In Condenser Tubes Exposed to River Water
Authors: McALLISTER R. A. , EASTHAM DONALD H. , DOUGHARTY NEIL A. , HOLLIER MITCHELL
Published: February 2013

The series of tests reported give quantitative data on the rates of fouling and corrosion in 17 to 20 ft condenser tubes under simulated operating conditions using Neches River water as the cooling medium. Alloys tested were: 90–10 Cupro-nickel, aluminum-brass, Alclad aluminum, admiralty, three stainless steels, and alloy 77. Heat-transfer coefficients and Fanning friction factors were measured three times daily for 3 to 4 months. Several mechanisms of the fouling rate function were employed to compare the results. It appears that the heat-transfer coefficient is essentially linear with time and that the rate of fouling, initially at least, is not a function of velocity, but is a function of chloride-ion concentration (or hardness). The effects of weekly caustic addition, continuous cathodic protection, and river-water velocity were examined. Other river-water variables measured included pH, chloride-ion content, and hardness. The effects of these variables are discussed qualitatively.

3.3.2, 4.6.7, 7.4.2
Some Corrosion Problems of Missiles in Silo Storage
Authors: Gatzek Leo E.
Published: February 2013

Explains corrosion problems that may be encountered in long term storage of missiles in underground silos. Discusses problems in controlling atmosphere inside the silo and the missile to prevent corrosion, corrosion control measures used and techniques used to measure corrosion. Detecting systems covered are visual and electrical methods. 7.1
Corrosion Product Films Formed on Aluminum In High Temperature Wester
Authors: MacLENNAN D. F.
Published: February 2013

A study was made of the behavior of aluminum alloys exposed to 300 G high purity water for short periods of time. The corrosion products formed were examined by means of optical and electron microscopy. Results show that corrosion resistance is associated with the distribution of second phase particles in the alloys. The alloy, which had the best corrosion resistance, contained the most uniform distribution of cathodic second phase particles; the corrosion product film of this alloy contained a corresponding distribution of irregularities. It is suggested that the second phase particles modify the film in such a way as to increase its protective qualities.

6.4.2, 4.6.5, 3.2.3
Elevated Temperature Corrosion Of Type 310 Stainless Steel By Vanadium Compounds
Authors: LOGAN HUGH L.
Published: February 2013

The mechanism of the attack of Type 310 stainless steel by vanadium compounds has been studied. Catastrophic attack by a mixture of 67 wt. percent V 2 O 5 + 33 wt. percent of NaVO 3 occurred at temperatures of 1900 to 2000 F if the steel had previously been oxidized and air and water vapor were present. In some instances an unidentified phase formed at the steel-slag interface attacked the steel by grain boundary penetration and adsorption of steel grains. A chemical analysis of the slag showed that the chromium-iron and manganese-iron ratios were the same in the slag as in the steel. The nickel-iron ratio, however, was higher in the slag than in the steel. This would suggest the possibility that nickel is selectively absorbed by the slag prior to general attack.

4.2.3; 4.3.3, 3.5.9, 6.2.5
Determining the Effect of Formulation On Physical Properties of Asphalt Mastic Coatings
Authors: SHEPPARD LYLE R.
Published: February 2013

Field and laboratory tests were made to determine the characteristics of asphalt mastic coatings which may affect their performance on pipe lines as a corrosion protection device and as a weighting agent. A Blunt Needle Penetration Test was developed to aid in control of the quality of finished mastic coatings. This test proved quite sensitive to both binder quality and the ratio of binder to aggregate. Laboratory measurements were made of such physical properties as binder softening point and penetration, bulk density, adhesion, cohesion, apparent voids, blunt needle penetration, and temperature characteristics. Purpose of tests was to determine the mastic quality and the influence of various mixtures on physical properties of the mastic. A number of extensive outside discussions are included together with the author's replies.

5.4.5, 8.9.3, 2.3.7
Corrosion of Metals by Weak Acids Under Heat Transfer Conditions
Authors: GROVES N. D. , EISENBROWN C. M. , SCHARFSTEIN L R.
Published: February 2013

Weight-loss measurements were made on six alloys: Types 304L and 316 stainless steels, Carpenter No. 20-Cb, Hastelloy B, Inconel and Monel in solutions of 10 percent, 50 percent and concentrated acetic acid, formic acid and phosphoric acid. A special heat transfer device was used to compare corrosion rates obtained with and without heat transfer. Metal temperatures of 230 F, 257 F and 284 F were studied. Carpenter No. 20-Cb and Hastelloy B consistently showed good corrosion resistance. Of the alloys tested Monel was the most sensitive to the effects of heat throughput.

4.3.2, 6.2.5, 6.3.10, 3.5.9
Development of a Mineral Scale Inhibitor
Authors: JONES L. W.
Published: February 2013

The expense attributable to scaling in oil producing operations totals many millions of dollars annually. Causes of precipitation and deposition are fairly well understood but better methods of control are needed. In order to evaluate chemical scale inhibitor components, a laboratory testing device was designed. Performance of sequestrants, surface active agents, colloids, and mixed compounds in the laboratory tester are discussed. Polyphosphates and sodium carboxymethyl cellulose proved effective for calcium carbonate scale and calcium sulfate scale, respectively. Results of tests made over a period of several years led to the development of an inhibitor composition that is capable of inhibiting both carbonate and sulfate scales. The inhibitor is now in field use. 5.8.2, 3.2.3, 8.4.3
High Temperature Sulfur Corrosion Of Intermediate Range Chromium Steels
Authors: HANNUM R. E.
Published: February 2013

Laboratory tests were made to find a suitable replacement material for 5 percent chromium— 1/2 percent molybdenum tubes used in a thermal desulfurization unit. The steel found most suitable for this use had a 9 percent chromium content. Maximum corrosion loss in wall thickness of this material was less than 0.030-inch, with a total expected life of at least five years. The sulfur content of various crudes commonly used in furnaces is reported.

8.4.3, 6.2.4
Suggested Mechanisms of the Changes With Time In WP-1 Wash Primer Metal Conditioning Composition
Authors: ALLEN EDWARD R.
Published: February 2013

A brief outline is given of the history of wash primers with emphasis on laboratory research. A mechanism is postulated to explain the loss of adhesion with time of WP-1. Topics discussed include phase rule studies of zinc tetraoxychromate, intrinsic viscosities of recovered polymers, reactions involving formation of phosphorus-chromius-resin complex, deposition of tertiary zinc phosphate on metal, and modifications made in WP-1. Several organic structural formulae are included.

5.4.5
Devices Used in Corrosion Control of Power Cables
Authors: POKORNY J. J.
Published: February 2013

This paper describes the various devices which are used in the corrosion control of underground power cables. Many of these devices have been used for a long time but the present paper describes a number of useful improvements in such devices as the electrolysis switch, the test current interrupter, and the cathodic protection and forced drainage rectifiers. The use of silicon power rectifier as an electrolysis switch is described. A method of grounding and corrosion protection of a pipe cable system is also outlined.

7.7, 5.2.1
Atmospheric Corrosion Testing of Metals in Canada
Authors: GIBBONS E. V.
Published: February 2013

The atmospheric corrosion resistance of metals is evaluated after exposure in a number of differing Canadian environments. Test sites included rural, industrial marine-industrial, marine, far northern and semi-industrial. Metals exposed include three aluminum alloys, aluminum coupled metals, carbon steel, copper-bearing low carbon steel, low alloy copper-nickel-bearing steel, three stainless steels, two magnesium alloys, and rolled zinc. Test exposure periods varied from one to ten years.

2.2.2
Weyerhaeuser's Experience: Corrosion Resistance of Stainless Steel Overlays in Kraft Digesters
Authors: Carns C. L.
Published: February 2013

Success with hand weld overlays of Type 310 stainless to repair corrosion damage in bottom cones of Kraft digesters at Longview, Wash., induced Weyerhauser to use Type 310 stainless steel to repair complete digester shells of five units in 1956. Automatic welding guns were used with argon gas. At Everett, seven more digesters were overlaid in much the same manner. Type 316 was used for work at Everett because, by the time work was begun, some failures had been noted in the upper parts of the units at Longview.

Analysis showed that the original weld material was being diluted by the base metal in the ratio of 1 to 2.

In an effort to reduce the amount of dilution experienced, alterations were made in the method of deposit on the upper shell of the final unit at Everett. The gun was tilted 20 degrees to normal to effect greater impingement on preceding beads. Weight of deposit was increased, and rate of feed of argon ^ gas also was increased to effect better shielding. The top four feet of the shell was given a double overlay. Tilting the gun did not materially improve the quality of the deposit. Double overlay produced a surface with an analysis close to that of the overlay wire.

Reports of inspections in several zones of the digesters are given. Significance of pits in overlaid material of this kind is emphasized.

Tests are being conducted using various types of weld overlay to find one more resistant. Some design changes were made in the digester. Impingement plates were installed to absorb erosive force of liquor and to provide cathodic protection to the overlay.

3.7.3, 9.6.6, 8.5.3, 6.2.5.
Corrosion of Carbon and Low-Alloy Steels In Out-of-Pile Boiling-Water-Reactor Environment
Authors: VREELAND D. C. , GAUL G. G. , PEARL W. L
Published: February 2013

Results are reported of extensive corrosion testing of carbon and low-alloy steels in a dynamic test loop simulating the various environments found in a nuclear boiling-water-reactor system. Quantitative data and metallographic and visual observations of specimens tested in saturated steam, saturated water and a steam-water mixture, all at 545 F and 1000 psi are presented. Water and steam conditions are based on 10 to 20 ppm oxygen in the steam with a 1:8 stoichiometric ratio of hydrogen to oxygen, a condition representative of the hydrogen and oxygen formed in a boiling-water reactor from radiolytic water decomposition. The water is maintained at pH 7, high purity with no other additives. A description of the boiling-water dynamic-test facilities and operating procedures is included.

Total corrosion and corrosion product released into the system is measured. No appreciable difference was noted among corrosion rates of carbon steels, high-strength low-alloy steels and alloy steels studied, although all showed higher rates than the AISI Type 300 series stainless steels tested. Comparisons also were made with other stainless steels. No selective attack was noted on welded specimens.

Corrosion rates obtained on the carbon and low-alloy steels are lower than those obtained by other investigators on similar materials in test loops simulating pressurized water-reactor systems operated at high pH (> 10) with only hydrogen gas in the water. The iron-to-system rates in the present tests were appreciably lower than those in similar tests in high pH and neutral pH systems with a hydrogen environment.

8.4.5, 6.2.3, 6.2.4
Zinc Filled Inorganic Coatings
Authors:   A Report of NACE Technical Unit Committee T-6B On Protective Coatings for Resistance To Atmospheric Corrosion,   Prepared by Task Group T-6B-11 on Zinc Filled Inorganic Coatings
Published: February 2013

This report considers in detail the uses of, corrosion resistance of, and application of, zinc filled inorganic coatings. Environments in which these coatings were exposed and evaluated include water and moisture, acids, oxidizing agents, alkalies, and solvents and oils. Properties of applied coatings considered include temperature limitations, impact and abrasion resistance, aging, toxicity and odor, weight, electrical properties, adhesion and gloss retention. Matters discussed in connection with application include coverage, flammability and toxicity, surface preparation, drying time, curing, baking, inspection and compatibility.

Total material cost for zinc filled inorganic coating systems ranged from eight to ten cents per square foot.

5.4.2
Use of Pipe-to-Soil Potential In Analyzing Underground Corrosion Problems
Authors: HUSOCK B.
Published: February 2013

An account is given of how pipe-to-soil potential measurements can be used to distinguish stray current corrosion from galvanic corrosion. General rules are given for the interpretation of a set of potential measurements in evaluating an underground corrosion problem in a non-stray current area. Data reported include potential profiles of (1) Galvanic corrosion activity (2) Pipe subject to exposure from cathodic protection interference. (3) Ungrounded coated pipeline, (4) Coated pipeline connected to copper grounding system, (5) Bimetallic effect. Several case histories are cited to show actual application of rules in evaluating corrosion problems in non-stray current areas.

4.5.3
Intergranular Sulfur Corrosion In Missile Thrust Chamber Nickel Tubes
Authors: STEVERDING BERNARD
Published: February 2013

In order to determine the conditions under which intergranular corrosion of nickel thrust chamber tubes takes place, studies were made of the corrosion pattern as simulated in laboratory experiments. Rapid intergranular corrosive attack by the small sulfur content of the fuel is possible only at temperatures above 550 C. Chemical surface reactions between nickel and the H2S of the fuel begin at considerably lower temperatures, but the grain boundary diffusion of the sulfur is the rate-controlling process. Vacuum heating rejuvenates corroded samples and restores the original ductility. Since the rejuvenated samples show a better resistance against corrosion than do original, unaffected samples, vacuum heating may be successfully applied as a corrosion-preventive measure. 3.2.2, 4.3.7, 6.3.10, 8.9.1
High Temperature Slag Corrosion of Metallic Materials
Authors: GREENERT W. J.
Published: February 2013

The relative resistance of various materials and alloys to corrosion by laboratory slags was studied. The materials of interest were subjected to three selected laboratory slags: vanadium slag formed by mixing 70 percent V2O5 and 30 percent Na2SO4, non sulfated vanadium slag formed by mixing 79 percent V2O5 and 21 percent NaVO3, and a sulfate-chloride nonvanadium slag formed from 90 percent Na2SO4 and 10 percent NaCl. Materials showing greatest corrosion resistance to these slags were Hastelloy D, 100 Cr, 50 Cr-50Ni, and 25 Cr-5 Al-bal Fe. Other materials of greater utility showing good resistance were 60 Cr-40 Ni, 30 Cr-30 Ni-40 Co, 14 Cr-14 Mn-bal Fe, and Haynes-Stellite 31. 4.2.3
Corrosion Inhibition of Aluminum-Zinc Alloy in Hydrochloric Acid Solutions
Authors: SHETH K. G. , CHAR T. L RAMA
Published: February 2013

Corrosion rates and inhibitor efficiencies in hydrochloric acid solutions have been determined for aluminum-zinc alloy containing 4.5–6.5 percent zinc. Percent efficiencies of the various inhibitors were in the ranges: acridine 80–98, thiourea 86–95, nicotinic acid 80–97, strychnine 64–94 and quinine hydro-chloride 58–95. Polarization studies with thiourea, strychnine and quinine hydrochloride showed that anode polarization is negligible, whereas cathode polarization is considerable. The Tafel plot is valid in this case. Dissolution of the metal is electrochemical in character. With these inhibitors the corrosion process appears to be essentially under cathodic control.

5.8.2, 6.4.2, 4.3.2
Electrochemical Techniques for Measurement And Interpretation of Corrosion
Authors: PHELPS E. H.
Published: February 2013

Corrosion of metals proceeds by electrochemical processes in most aqueous environments. Hence, electrochemical techniques can be used to study and interpret corrosion phenomena and, in certain instances, to measure the rate of corrosion. Corrosion-potential measurements furnish information on whether the anodic or cathodic process, or both, are controlling corrosion. They may also furnish useful information on film breakdown or film repair.

Measurement of the potential distribution in solution by the probe method is laborious but does afford a means of determining corrosion rate and distribution of corrosion. Some of the difficulties of the probe method can be overcome by using a rotating-electrode technique that permits direct observation of the distribution of anodic and cathodic areas. Divided-cell experiments, in which pitted areas are separated from unpitted areas, permit determination of local-cell polarization diagrams as well as rate of corrosion.

The polarization behavior of corroding metal electrodes can be used in several different ways to measure the rate of corrosion. A promising recent development in this area is the polarization-resistance method, in which the initial slope of a polarization curve can be used to obtain a reliable estimate of the rate of corrosion.
Laboratory Flow Test for Evaluation Of Oil Well Corrosion Inhibitors
Authors: BARRETT J. P. , CLAYTOR E. E.
Published: February 2013

Previous laboratory evaluations of downhole oil well corrosion inhibitors have been performed using static methods. In order to obtain results more accurately reflecting inhibitor efficiency under conditions of flow, the type of exposure which usually occurs in producing operations, a dynamic test method has been devised. This is a more severe measure of inhibitor film life than the static bottle test.

Good correlation has been obtained between the laboratory dynamic test and field use of inhibitors, in both sweet and sour oil well systems.

5.8.4, 2.3.7, 3.5.11, 8.4.3
Stress-Corrosion Cracking of Steels In Agricultural Ammonia
Authors: LOGINOW A. W. , PHELPS E. H.
Published: February 2013

Stress-corrosion cracking has been determined as the cause of failure of carbon steel tanks in agricultural ammonia service. Effects of ammonia contaminants, such as air, water, carbon dioxide, oil, etc on failure rates were studied. In general, air contamination increased stress-corrosion cracking and water in small amounts inhibited the attack.

For prevention of such failures, it was recommended that high residual stresses in ammonia vessels be avoided by the use of stress relieving treatments, that air be eliminated from agricultural ammonia systems and that the ammonia should have a minimum water content of 0.20 percent.

3.5.8
Some Electrochemical Methods in Corrosion Research
Authors: MAKRIDES A. C.
Published: February 2013

Three principal electrochemical methods used in corrosion research are reviewed and typical applications are given. The direct method for obtaining polarization curves is discussed in detail. Potentiostatic methods and their application to inhibition and anodic protection are described. The use of impedance measurements in corrosion research is also discussed briefly.

2.3.5, 3.8.2, 5.8.1, 5.2.1
Joint Action of Hydrogen Sulfide and Organic Compounds On Corrosion and Embrittlement of Iron in Sulfuric Acid
Authors: IOFA Z. A. , TOMASHOVA G. N.
Published: February 2013

Although hydrogen sulfide is known to be highly corrosive to iron, it has been found that the presence of H2S actually enhances the inhibiting qualities of certain classes of organic compounds when employed as inhibitors of iron corrosion in sulfuric acid solutions. At the same time, the corrosivity of the hydrogen sulfide itself is eliminated and hydrogen embrittlement prevented.

Certain other classes of organic compounds do not have these inhibiting qualities under similar conditions but instead tend to intensify attack by hydrogen sulfide.

Experimental results, polarization curves for the systems tested, and sulfur adsorption measurements on iron provide preliminary information on the mechanism of the joint action of organic compounds and hydrogen sulfide on iron corrosion in acid media.
Stress-Corrosion Cracking Investigation Of Two Low Alloy, High-Strength Steels
Authors: DAVIS ROBERT A.
Published: February 2013

Laboratory stress corrosion testing with an improved test specimen configuration has been conducted on 4330M and 4340 steel billet material to evaluate grain direction and surface finish effects. The transverse grain directions were found to be the most susceptible to cracking. Surface finishing by chemical milling, electropolishing and grinding increased stress corrosion susceptibility. Surface finishing by grit blasting, shot peening and face milling increased resistance to cracking. Cracking appeared to be intergranular with respect to the prior austenite grain boundaries. Fractographic studies with the electron microscope suggest that hydrogen embrittlement and stress-corrosion cracking may be fundamentally related.
Improved Laboratory Technique for Investigating Corrosion by Recirculating Cooling Water
Authors: FISHER A. ORMAN
Published: February 2013

A description of an improved testing loop for the evaluation of cooling water corrosion inhibitors for open recirculating systems is given, together with the performance characteristics of the laboratory apparatus. The test equipment included heat transfer surfaces and permitted velocities of 2 to 3 feet per second. Corrosion rate comparisons are made with data previously obtained in a screening test loop operated under less severe test conditions.

Attempts are made to detect the extent of scale build-up on heat transfer surfaces through losses in heat transfer and increased friction losses in the system. Results indicate that scaling and fouling characteristics of inhibited open cooling water systems were not satisfactorily measured in the apparatus described.
Influence of Oxygen on High Temperature Aqueous Corrosion of Iron
Authors: RUTHER W. E. , HART R. K.
Published: February 2013

The corrosion of pure iron in distilled water was investigated over a range of temperature (50–315 C) and oxygen content of the water (<0.1 – 540 ppm).

A uniform brown-black coating formed in water of low oxygen content at 260 C. The corrosion rate was low after the initial period.

Severe pitting of the iron was encountered in water containing intermediate concentrations of oxygen over the entire range of temperature. The average metal loss rates were also much higher than that obtained in a low oxygen environment.

A thin protective film formed when adequate oxygen was present. No significant pitting was noted. The total corrosion at 30 days' exposure was lower for samples in a 26OC–540 ppm oxygen test than for those with very little oxygen at the same temperature.

The protective film forming ability of iron in a pitting oxygen-water environment was improved by alloying, particularly with chromium and carbon. The improved corrosion performance of some mild and low alloy steels over pure iron at intermediate oxygen concentrations was also noted.

The thin films formed on pure iron in adequately oxygenated water were composed of α-Fe2O3 (hematite) as contrasted with the Fe3O4 (magnetite) coatings produced in deoxygenated water. Distinctive growth habits for the various iron oxides were found on the outer surfaces of the protective coatings.
Effect of Solution Heat Treatment on Corrosion Kinetics Of Zirconium in 20 Percent Hydrochloric Acid At High Temperature and Pressure
Authors: KUHN WILLIAM E.
Published: February 2013

An investigation has been made of the influence of amount and distribution of precipitate phase on the corrosion kinetics of “low purity” zirconium in 20 percent hydrochloric acid at 200 C. It was found that minimum corrosion rates, coincident with minimum values of activation energy and frequency factor in the Arrhenius relationship, were obtained by solution heat treatment at 700 C followed by water quenching. Such heat treatment gave a corrosion rate equivalent to that of alpha annealed iodide zirconium. A maximum corrosion rate was obtained by a beta solution treatment at 890 C followed by water quenching, whereas beta solution treatment at 1000 C gave sharply reduced corrosion rates. Nature of distribution of the precipitate phase profoundly influenced corrosion rate. A discontinuous pattern of intergranular and transgranular globular particles was substantially less deleterious than the same amount of impurity phase finely disseminated throughout the microstructure.

The results of the investigation are discussed in terms of the possible roles of chlorine and hydroxyl ions in the corrosion mechanism. Relative effects on corrosion kinetics of statistical distributions of active sites (each characteristic of lattice configurations produced by lattice defects, solute atoms and precipitation phenomena) are also considered.
Corrosion Engineering And Corrosion Science
Authors: FONTANA M. G.
Published: February 2013

The corrosion scientist and corrosion engineer are complementary; their efforts are synergistic in solving problems of corrosion control.

The broad background of a corrosion engineer capable of covering the entire field of corrosion engineering includes knowledge of chemistry, metallurgy, physical, chemical and mechanical properties of materials, electrical engineering, mechanical engineering, biology, stress analysis, economics, human nature and many other fields.

The corrosion scientist and corrosion engineer should regard each other with equal esteem, the only basis for evaluating the other's efforts being quality of work.
Corrosion Resistance in Sea Water Of Medium Strength Aluminum Bronzes
Authors: UPTON B.
Published: February 2013

The corrosion resistance of aluminum bronzes of the 90/10 type is good, providing eutectoid decomposition of the beta phase to alpha + gamma2 is prevented. If gamma2 is present, it is highly anodic to the alpha matrix and rapid corrosion will occur. Retention of beta is favored by a fast cooling rate and a high manganese content. Nickel and iron are of less significance and the effect of aluminum is dependent upon the percentages of other elements present. In general, however, beta retention is favored by a low percentage of aluminum. Silicon additions give rise to a close-packed-hexagonal kappa phase which is not easily decomposed to alpha + gamma2. The result is that the microstructures of certain Cu-Al-Si alloys are less sensitive to cooling rate; hence, a reliable corrosion resistance is more easily obtained.
Corrosion Resistance of Molybdenum Modified Cr-Ni-Mn Austenitic Stainless Steels
Authors: NAIR F. , SEMCHYSHEN M.
Published: February 2013

The corrosion resistance of nine Cr-Ni-Mn austenitic and duplex austenitic-ferritic stainless steels, containing up to 5 percent molybdenum, in hot deaerated sulfuric acid and boiling concentrated nitric acid was determined and compared to the behavior of recognized commercial grades. A limited evaluation of mechanical properties was performed.

The corrosion resistance of these alloys was affected by molybdenum additions in a manner similar to that observed in Cr-Ni austenitic steels:The ability to tolerate minimal oxidizing environments such as sulfuric acid was markedly improved.The resistance toward strongly oxidizing acidic conditions was reduced.

The presence of delta ferrite effected improved resistance in sulfuric acid and materially diminished corrosion resistance in hot nitric acid.
Influence of pH on Corrosion and Passivation of Nickel
Authors: DAVIES D.E. , BARKER W.
Published: February 2013

Anodic and cathodic polarizations of nickel have been studied using a galvanostatic technique with low current densities and an atmosphere of hydrogen. Polarization experiments have been conducted using 0.1 N sodium hydroxide, 1 N sodium carbonate and 0.1 N sodium borate solutions. It has been shown that passivation is caused by the formation of a monomolecular layer of Ni(OH)2 in alkaline solutions and by 1–2 molecular layers in borate solution. On further oxidation, the Ni(OH)2 becomes oxidized to Ni2O3 and finally to a nonstoichiometric oxide corresponding to NiO1.8. This final oxidation state is unstable and decomposes as soon as the electrode is made cathodic. It has been shown that current density has a critical effect on polarization characteristics in the borate solution. No evidence was found for the existence of the intermediate oxide Ni3O4.
Effect of Heat Treatment, Composition and Microstructure on Corrosion of 18Cr-8Ni-Ti Stainless Steels in Acids
Authors: STREICHER MICHAEL A.
Published: February 2013

Titanium additions to 18Cr-8Ni steels can effectively eliminate susceptibility to intergranular attack associated with the precipitation of chromium carbides. However, these additions also drastically reduce the grain size of these steels and promote the formation of sigma phase. Both of these factors modify the behavior of titanium-stabilized steels in corrosive environments. A detailed investigation of the influence of heat treatment and microstructure on the corrosion resistance of four titanium-stabilized, AISI 321, heats is described.

Incomplete stabilization of carbon by titanium leads to precipitation of chromium carbides on heating in the range of 800 F to 1600 F. This type of susceptibility is readily detected in the oxalic acid etch test, the nitric-hydrofluoric acid test, the copper sulfate-sulfuric acid test, the ferric sulfate-sulfuric acid test, and in the nitric acid test.

A second type of susceptibility to intergranular attack is associated with the formation of sigma phase, which may precipitate in a sub-microscopic form during heating in the range of 1150 to 1550 F. It is detected only in the nitric acid test and, to a lesser extent, in the ferric sulfate-sulfuric acid test.

The action of various acid solutions on titanium-stabilized stainless steels are compared by means of metallographic studies of microstructures and of progressive corrosion, and by measurements of weight loss and change in electrical resistance of corroding specimens. The data obtained are used to explain the action of acids on these steels and to recommend procedures for evaluation testing.
Theory Of Stainless Steel Pitting
Authors: SCHWENK W.
Published: February 2013

Pit origin and formation in stainless steels are discussed according to results of investigations from the following points of view:

1. Conditions for the Existence of Pitting Corrosion.

Pitting potential range and pitting potentials. Functions dependent on the potential which are important for pitting corrosion, effect of inhibitors and results of different methods of investigation are described.

2. Kinetics of Pitting Corrosion.

Analysis of the current-time relationship gives information on dependence of potential on the anodic metal dissolution process. Pit growth under potentiostatic, galvanostatic and chemical corrosion conditions can be explained theoretically.

3. Physical Forms of Pitting Corrosion.

Shape of pits that can be observed in different potential ranges and under different corrosion conditions are discussed: regular etch pits, hemispherically-shaped pits, under-hollowing and elongated areal pits.

4. Theoretical Explanation of Pitting Corrosion.

In connection with the “all-or-none” principle of passivity, which holds that the active and passive states should not coexist at the same potential, it is shown under which circumstances stable pitting corrosion is possible. A concentration effect and a resistance polarization effect are discussed in detail. The origin of pitting corrosion and the pitting potentials are discussed in terms of a chemisorption process and a transport and/or transference theory.
Corrosion of Lead by Alternating Current
Authors: GALIMBERTI C. E.
Published: February 2013

From laboratory tests, it appears that corrosion of buried, lead-sheathed cables by alternating current is due to current leakage through breaks in the insulating coating. Even though the current flow in the lead sheathing may be small, it becomes concentrated, i.e., its density increases considerably at small openings through which the current is grounded into the soil.

In tests in which direct current was superimposed on alternating current flowing to lead electrodes immersed in tap water, the corrosion of the electrode acting as anode was increased; corrosion of the cathode was decreased.

Lead may also be cathodically protected by connecting it with a less noble metal, such as Fe, Zn or Mg. In the case of Mg, when connected so that it conducts the current rectification occurs which results in increased corrosion of the lead.

The morphology of corrosion of lead by alternating current is characterized according to whether the anions present form soluble lead compounds (nitrate or acetate, for example) or insoluble products (sulfate or carbonate).
Preparation and Evaluation of Clean Metal Surfaces
Authors: LINFORD HENRY B.
Published: February 2013

The improbability of preparing an absolutely clean metal surface, even in the laboratory, is discussed. In the light of the difficulties in achieving such a goal the methods used to prepare surfaces as nearly free of contaminants as possible are presented.

The contaminants most commonly found on metal surfaces are divided into two groups depending upon their wettability. They are hydrophobic (nonwettable) and hydrophilic (wet-table). The hydrophobic contaminants are, for the most part, polar organic compounds and mixtures of such materials. The polar group most commonly encountered is COOH, which is present in common oils, fats, greases, etc. These compounds are very strongly adsorbed onto metal; in fact, chemisorption is very common. The usual methods for removal of such surface contaminants are given, followed by a quantitative comparison of the various tests available for the resulting cleanliness. The hydrophilic contaminants, which can best be represented by oxides, are then discussed, including tests for their presence and methods of removal.