The Influence of Ozone on the Electrochemical and Corrosion Behavior of Metals in Acid Media

The corrosion–electrochemical behavior of 092, 0817, 1017132 steels, 0628 alloy, and such metals as aluminum, chromium, and nickel are investigated in ozonized acid media. The effect of ozone on the corrosion–electrochemical properties of these metals are shown to be ambiguous.     

The Corrosion of Alloy Steels under Antirust Compounds in the Presence of Microbes

The kinetic corrosion characteristics of 352-, 302, and 30 steels with rust-preventive compounds applied are investigated in an industrial neutral electrolyte, depending on whether a compound is infected with microorganisms or not. The effect of microorganisms and their metabolites on the corrosion of steels greased with the compounds are assessed.     

Protection of Sintered Steels against Corrosion in Neutral Media with an N-M-1 Inhibitor

The effect of an N-M-1 inhibitor (a salt of cyclohexylamine and C₁₀ to C₁₆ aliphatic acids) on the corrosion of sintered powder steels 13 and 141 (with the 14 to 17% porosity) in distilled or tap water at 20 to 80°C, as well as in 0.05 M Na₂SO₄ solution, is studied by gravimetric and electrochemical methods. The protective concentration of the inhibitor is lower in distilled, than in tap water or sodium sulfate solution. The protective action decreased with an increase in temperature. In tap water or sodium sulfate solution, the corrosion-inhibiting effect is weaker for 13 than for 141.     

X-ray topographic study of β-NiAl upon growth of an α-Al2O3 film

The Berg-Barrett X-ray topographic method was employed as a microstructural technique to seek correlations of the metal substructure to the morphological features of -Al₂O₃ films grown on -NiAl. An analysis of diffraction micrographs using {112} and {002} reflections from individual grains in -NiAl revealed its subgrain structure to a depth of 30 . The dimensions of these subgrains were directly related to the density of oxide ridges in the -Al₂O₃ films and to the dimensions and shapes of cavities at the NiAl-Al₂O₃ interface.     

Optically Scanning the Morphology of Protective Layers and Forecasting the Corrosion Resistance of Thermally Oxidized Steel

The results of investigating the morphology and protective properties of surface layers obtained on chromium steel 1810 by oxidizing in air at a temperature of 140 to 950°C are considered. After a special digital treatment, the scanned optical images of a small surface area probed allow one to introduce and determine those parameters of the morphological nonuniformity of the thermal oxide layer which affect its protective ability. Corrosion tests of oxidized specimens confirmed the applicability of the scanner morphological control to predicting the protective properties of thermal coatings against pit corrosion in chloride-containing electrolyte solutions.     

Metastable manganese austenite as a structural base of high-stability steels conditions of dynamic contact loading

Important regular features of the structure and special features of the behavior of metastable manganese austenite under conditions of quasistatic deformation and dynamic contact loading are considered. Based on the correlation of the energy of packing defects of manganese austenite with the kinetics of deformation martensitic transformations { , } and the capacity for deformation strengthening and relaxation of stresses, principles for choosing the base composition of metastable austenitic steels with a high operating stability for different conditions of dynamic contact loading are established.     

Resistance of 1201 aluminum alloy to plastic deformation at various strain rates

Conclusion With an increase in the rate of plastic strain there is a change in the resistance of 1201 alloy to plastic deformation, which is revealed in a nontraditional decrease in _0.2 and increase in , and A_p. The characteristics _k and _t increase nonlinearally.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 56–61, August, 1989.     

Thermal Resistance of Low-Alloyed Chromium Alloys

The oxidation kinetics of low-alloyed -2 and 1-17 chromium alloys is investigated at a temperature from 1273 to 1673 K for 1000 h. It is shown that even at a temperature from 1473 to 1673 K the heat resistance of these alloys is higher than that of the 648 nickel-containing alloy at a temperature from 1273 to 1373 K. This allows to recommend the alloys as heat-resistant materials operating at a temperature up to 1573 K.     

Solubility of β-stabilizers in α-titanium

Conclusions We have determined the solubilities of iron, chromium, manganese, silicon, copper, molybdenum, vanadium, and tantalum in -titanium (Table 1) and in the -solid solution of Ti+6% Al (Table 2).Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 13–16, February, 1963     

Austenitic stainless steels strengthened by phase strain hardening and aging

Conclusions Nonmagnetic stainless steels of the Kh12N12T3 and Kh12N14T3 type have good mechanical properties after phase strain hardening and aging (_0.2 = 685 - 785 MPa, _b = 1275 MPa, 20%) as compared with the properties of Fe-Ni-Ti austenitic steels with 26–30% Ni. After phase strain hardening and aging the stability of these steels is high with respect to the transformation during cold treatment.IFM UNTs AN SSSR. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 57–60, June, 1981.     

Phase and structural transformations in deformation and heat treatment of 08Kh15N5D2T steel tubing

Conclusion Annealing in the intercritical area of the -transformation or hardening from a continuous furnace with subsequent tempering in the -transformation range included in the production plan for cold-rolled 08Kh15N5D2T tubing do not restore the original workability of the steel since the residual austenite is stabilized toward the -transformation in deformation. Annealing at 650°C does not lead to complete recrystallization and detexturing of the metal. To obtain this it is recommended that rapid electric heating for hardening with subsequent tempering be introduced into the production plan for rolling of tubing.Ural Polytechnic Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 7–11, August, 1990.     

General laws governing variation in properties of cast alloys of the Al-Zn-Mg system

Among existing high-strength corrosion-resistant aluminum alloys, those of the Al-Mn-Zn system are most promising. They have a different phase composition, depending on the content of magnesium and Zinc: + (Al₃Mg₂), + + T(Al₂Mg₃Zn₃), + T, + T + (MgZn2) and + The majority of industrial Al-Mg-Zn alloys correspond to the phase regions + T and + T + with respect to composition. A high level of strength and satisfactory overall corrosion resistance are characteristic for these alloys. Al-Mg-Zn alloys may, however, tend to the most dangerous form of corrosion - stress-induced corrosion cracking. Using methods of experiment planning in the study, we investigated Al-Zn-Mg alloys of various compositions for the purpose of selecting alloy compositions with a high level of mechanical properties and stress-induced corrosion cracking.All-Union Scientific-Research Institute of Aviation Materials. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 24–28, December, 1994.     

Structural parameters of structural steel determining its resistance to hydrosulfuric cracking

Conclusions To attain high resistance to hydrosulfuric cracking of steels for drive pipes, it is necessary after heat treatment to attain a structure with the following parameters: size of the coagulated carbide (M₃C) particles d0.05 m to eliminate the possibility of nascent hydrogen accumulating on the carbide-matrix interfaces; subgrain size d>0.30 m to ensure relief of internal stresses, and dislocation density p<-10⁹ cm^–2 to eliminate places of possible localization of hydrogen.I. P. Bardin Central Research Institute of Ferrous Metallurgy. Siberian Branch of the Special Design Bureau of the Scientific and Production Association Soyuzgazavtomatika, Saratov. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 11, pp. 19–20, November, 1991.     

Evaluation of the Brittleness of Titanium Alloys in Terms of Mechanical Properties and Fracture Patterns

The phenomena of brittleness of structural -pseudo-- and ( + )-titanium alloys are analyzed and generalized using the results of tests of rupture specimens and various parts. The characteristics of ductility (elongation and contraction ) are used for evaluating the macroscopic manifestations of embrittlement, and the appearance of fracture surfaces as observed in electron microscopic diffraction patterns is used for estimating the micromanifestations of embrittlement.     

Mechanisms of the effect of vanadium,niobium, and titanium doping on the structure and properties of low-pearlite steels

Conclusions The favorable effect of doping with carbonitride-forming elements-vanadium, niobium, and titanium — on the structure and properties of low-pearlite steels subjected to controlled rolling is due to the change of the structural state of hot-deformed austenite, of the temperature range and nature of the -transformation, of the phase composition of the steel, and of the state of the -solid solution caused by the alloying with these elements.The ambiguous effect of doping with vanadium, niobium, and titanium on the strength and ductile properties of low-pearlite steel is due to the different degree of dispersion hardening, refinement of the ferrite grain, refinement of the solid solution, the ratio of the structural components, and the nature of the products of the -transformation.The newly devised economically alloyed low-pearlite steel 09G2FB for gas pipes with large diameter after controlled rolling with deformation at the concluding stage in the biphase +-region has a unique complex of mechanical properties satisfying the stringent requirements concening pipes intended for operation under conditions of the Far North.I. P. Bardin Central Scientific-Research Institute of Ferrous Metallurgy. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 11, pp. 13–22, November, 1984.     

Effect of Palladium Incorporation on Isothermal Oxidation Behavior of Aluminide Coatings

A (Ni, Pd)Al coating has been prepared by low-pressure pack cementation on the nickel-base superalloy IN738 with a preplating of Pd–20 wt.% Ni alloy. The coating consists mainly of a single phase of -Pd(Ni)Al in the outer part and -Ni(Pd)Al in the inner part. The oxidation behavior of the (Ni,Pd)Al coating at 900–1100°C was studied by TGA, XRD, and SEM/EDS. Results show that the transformation of - to -Al₂O₃ is more rapid on the (Ni,Pd)Al coating than that on a simple NiAl coating. The addition of Pd to the aluminide coating facilitates the transformation of - to -Al₂O₃e oxide scale formed and accelerates the diffusion of Ti from the substrate to the coating surface simultaneously.     

Corrosion of High-Strength Cr–Mn Steels in Chloride Solutions

High-nitrogen Cr-Mn steels 12X18A18 and 05X18A19 are attacked by pitting in NaCl solutions at > 0.1 g-ion/l and T > 313 K because the protective properties of their passive surface films deteriorate (their resistance decreases by a factor of three to six). The passivity range of these steels narrows to 87 and 90 mV at their corrosion depth indices of 1.2 × 10^–3 and 8 × 10^–4 mm/year, respectively. Pitting of 60X38H8B Cr-Mn-Ni steel exposed to NaCl solutions was observed at > 0.3 g-ion/l and T > 303 K. Its corrosion depth index increases to 1.48 mm/year. At < 0.1 g-ion/l, all the steels studied are highly resistant to corrosion.     

Two-phase ferritic-martensitic steels

Conclusions The results of laboratory and production experiments showed that the main condition for providing the necessary combination of properties of two-phase ferritic-martensitic steels (high tensile strength, low yield strength, high plasticity and work hardenability) is obtaining the specified quantity of the hardening phase (martensite) in the structure (20–28% M to obtain _t 550 MPa or 10–18% M for _t 450 MPa). The specified ratio of the structural constituents under conditions of mass production of two-phase ferritic-martensitic steels may be guaranteed only with the use of steels containing carbon and alloy elements within the necessary limits and also with strict observance of the heat-treatment cycle. Without the use of metallographic measurements as the criteria for obtaining the optimum structural condition in addition to the required values of strength and plasticity it is necessary to use the _0.2/_t ratio, which must not be greater than 0.5–0.6 with the absence of yield points on the tensile curve (without special temper rolling).As the result of the combination of work done in the Central Scientific-Research Institute of Ferrous Metallurgy together with plants of the Ministries of Ferrous Metallurgy and of the Automobile Industry at present the production is being introduced and experimental production lots of heat-treated two-phase steels of the following types with guaranteed mechanical properties are being supplied:At the Novolipetsk Metallurgical Combine cold-rolled 0.7–2.0-mm sheet of 06KhG(S)Yu and 06G2SYu steels with _0.2 = 260–320 MPa, _t 550 MPa, ₄ 30%, and _0.2/_t 0.5–0.6.At the Cherepovets Metallurgical Combine hot-rolled 2–6-mm sheet of 09G2(S) steel with _0.2 = 260–320 MPa, _t 550 MPa, ₄ 25%, and _0.2/_t 0.5–0.6.At the Beloretsk Metallurgical Combine (billets melted and rolled at the Cherepovets Metallurgical Combine) heat-treated cold-drawn wire up to 10.5 mm in diameter of 06KhGR steel with _0.2 250 MPa, _t 530 MPa, and ₁₀ 30%.For successful development of the production and use of two-phase ferritic-martensitic steels the combined work of the designers of machine building plants on determination of the most effective types of parts, of engineers on correction of the method taking into consideration the specifics of the properties of two-phase ferritic-martensitic steels, and of users on determining the service properties of parts of these steels is necessary. The fulfillment of such a combination of work will make possible th timely formulation of the further work of the metallurgical industry and determination of the required volume and product range of rolled products of two-phase ferritic-martensitic steels.I. P. Bardin Central Scientific-Research Institute of Ferrous Metallurgy. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 11, pp. 25–29, November, 1984.     

Mechanical properties of alloy KhN35VTYu at low temperatures

Conclusion Alloy KhN35VTYu has high values of _u, _0.2, and a_0.25 at normal and cryogenic temperatures after hardening at 1050°C for 3 h in air and aging at 700°C for 3–8 h. The alloy is not sensitive to stress concentration. Increasing the hardening temperature to 1200°C leads to a significant decrease in the values of _0.2 and a_0.25.VNIIÉM, IMASh. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 28–29, May, 1991.     

A Study of the Effects of Motion on Mass Transfer in Pits in a Two-Disk Hydrodynamic System

Effects of medium motion on the mass transfer in model pits in a two-disk hydrodynamic system are studied. Steel 121810 in sodium chloride solutions at 293 to 333 K was an object of the study. The dependences obtained allow evaluating the effects of medium motion on mass transfer in a model pit, depending on its geometrical parameters.