Influence of original structure and heating rate on the properties of steel after hardening from the intercritical range

Conclusions The original condition and heating rate determine the mechanical properties of the steel after hardening from the intercritical range. The best properties, particularly ductility, _t=1600 MPa, _0.2=1250 MPa, =14%, anda _n=0.9 MJ/m², are obtained after preliminary hardening from 930°C, tempering at 200°C, a second hardening from 800°C (5% ferrite), and tempering at 200°C. Full hardening from 930°C with subsequent tempering at 200°C (without preliminary hardening) makes it possible to obtain _t=1550 MPa, _0.2=1200 MPa, =9%, anda _n=0.9 MJ/m².Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 52–56, May, 1981.     

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.     

Strengthening heat treatment of alloy VT16 in vacuum

Conclusions Alloy VT16 can be strengthened by heat treatment in vacuum under the following conditions: heating at 775–800° for 2 h, cooling in the container in water, and aging at 500° for 8 h.The alloy subjected to this treatment has the following properties; _b = 103–107 kgf/mm², =59–63%, ₅ = 15.1–16.1%.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 65–67, May, 1978.     

Effect of nitrogen and chromium on the mechanical properties of austenitic steels at −196°C

Conclusion Nitrogen lowers and chromium raises (with >3% N) the strength (_b0.2), ductility (, ), and fracture toughness of austenitic stainless steel of the Kh(18-24)N20 type in the aged condition. The effect of chromium on the properties is due to a change in the solubility of nitrides.I. P. Bardin Central Scientific-Research Institute of Ferrous Metallurgy. Translated from Metallovedenie Termicheskaya Obrabotka Metallov, No. 8, pp. 6–8, August, 1979.     

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.     

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.     

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.     

Effect of warm extrusion on structure and properties of steel 20Kh

Conclusion Warm extrusion of steel 20Kh at 600–800° makes it possible to obtain a structure with high strength and ductile characteristics: _0.2=40–50 kg/mm², _b=50–60 kg/mm², =60–75%.Voroshilovgrad Machine Construction Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 56–57, March, 1976.     

Mechanical properties of steel 30KhGSA with grains of different sizes

Conclusions Grains of different sizes impair the ductile characteristics of steel. This is manifest in a reduction of the resistance to brittle fracture, which is particularly notable for samples tempered at high temperature and brittle samples. The strength characteristics (_b, _0.2, HRC) and ductility (, ) of quenched and tempered steel vary negligibly with the grain size, and therefore static tests of smooth samples are inadequate to determine the service life of such materials.I. P. Bardin Central Scientific-Research Institute of Ferrous Metallurgy. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 52–53, December, 1977.     

Analysis of fatigue curves for alloy 36NKhTYu in the quenched and annealed conditions

Conclusion The limiting cycle amplitude in alloys is determined by friction stress which hinders dislocation movement, and in the region of stresses satisfying the condition _m + _{m f} it does not depend on the magnitude of the static component of the stress cycle.Novosibirsk Pedagogical Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 21–23, March, 1991     

Mechanical properties of alloy KhN40MDTYu at low temperatures

Conclusion The optimal strength, ductility, and toughness of alloy KhN40MDTYu at cryogenic temperatures result from quenching + aging or from deformation with no heat treatment: _b = 180kg/mm², _0.2 = 100–120 kg/mm², =20%, =15%,a _n=5–7 kg-m/cm² at –253°C.Central Scientific-Research Institute of Ferrous Metallurgy. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 64–65, July, 1972.     

Effects of the composition and low-temperature thermomechanical treatment on the mechanical properties of structural steels

Conclusions The investigation of the effect of thermomechanical treatment on the mechanical properties of steels with different compositions makes it possible to put in evidence the effect of alloyed elements. The addition of up to 1.2–1.5% Si (particularly with vanadium) makes it possible to increase the tempering temperature to 350°C without significantly decreasing the strengthening effect of low-temperature thermomechanical treatment. An increase of the concentration of chromium from 1.5 to 3–5% also increases the resistance of the steel. In steel containing 3–5% Cr and also molybdenum, vanadium, and tungsten, the effect of low-temperature thermomechanical treatment is retained after tempering at temperatures up to 500°C, the plasticity remaining rather high. Low-temperature thermomechnical treatment of batches 8 and 10 followed by tempering at 500°C resulted in the following mechanical characteristics: _b=240–255 kg/mm² when =10–13% and =30–35%; after tempering at 350°C _b=255–265 kg/mm², ₅=8–12%, and =28–36%.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 36–40, April, 1963     

Effect of differences in grain size on the mechanical properties of steel 18Kh2N4MA

Conclusions A difference in grain sizes has a negative effect on the ductile characteristics of steel. The ductile characteristics (T₅₀,ap) of the steel with differing grain sizes (grades 1 and 8) are slightly better than those of the coarse-grained steel (grade 1). A difference in grain size mainly lowers the resistance to ductile (ap) and brittle (T₅₀) fracture. The strength characteristics (b, _0.2), hardness (HRC), and ductility (, ) of the quenched and tempered steel do not depend greatly on the original austenite grain size. With ductile fracture the negative effect of a difference in grain size is more evident after high-temperature tempering. A difference in grain size has the same negative effect on the ductile-brittle transition temperature (resistance to brittle fracture) after tempering at both low and high temperatures.I. P. Bardin Central Scientific-Research Institute of Ferrous Metallurgy. Translated from Metallodenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 2–5, April, 1977.     

Hardening of welded joints in titanium alloys,produced by electron-beam welding

Conclusions The ultimate strength of welded joints in alloys VT6S, VT14, VT23, and VT19 is 1100, 1150, 1300, and 1250 MPa, and the effectiveness of hardening, _u=200, 250, 300, and 250, respectively, as a result of hardening heat treatment — quenching from the temperature of the upper boundary of the (+)-region and subsequent aging at 450–560°C.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 52–54, January, 1985.     

Oxidation Behavior of Two-Phase γ + σ Nb-Ti-Al Alloys

The oxidation behavior of a series of single-and two-phase Nb-Ti-Al alloys, selected from the sameextended + tie-line, was investigated at1200°C in air. The single-phase alloy suffered from extensive internal oxidation andoxidized at a much higher rate than the single-phase alloy. In a two-phase + microstructure, the phase was preferentiallyattacked to form internal alumina andTi-rich nitride. This preferential attack of limited the extent to which the phase wasinternally oxidized, but also interrupted the formationof a continuous alumina scale. The single-phase alloyalso did not form a continuous alumina scale. Theinability of the phase to form continuousalumina was attributed to a combination of nitrideformation and internal oxidation. The oxidation behaviorof the two-phase + Nb-Ti-Al alloys isdiscussed in terms of mechanisms developed for theoxidation of binary, two-phase alloys.     

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.     

Heat-treatment with induction heating of pipes within the pipe welding mill

Conclusion Induction heat treatment of corrosion-resistant steel pipes in the line of an argon-arc welding mill produces a fine-grain structure of the base metal and weld, ensures the mechanical properties of pipes as specified in GOST 11068-81: _t 560 N/mm²; ₅ 36%. and also makes possible the oxidation of the metal by 0.33%, reduces the time and consuption of the etching solution during chemical processing, and saves power.Dnepropetrovsk, Moscow Pipe Works. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 26–29, August, 1987.     

Dependence of the Protective Concentration of a Mixture of Inhibitors from Several Reaction Series on the Polarities of Substituents in Their Molecules

Protective concentrations of mixtures of inhibitors from several reaction series (RSs), which decrease the corrosion rates a given number of times, are exponentially dependent on the sum of partial polarities of substituents in compounds belonging to the chosen RSs, provided that the total concentration of compounds for each RS is constant. The dependence is linearized in semilogarithmic log C _prvs – m coordinates.     

Effect of tempering under stress on the mechanical properties and relaxation resistance of austempered reinforcing wire

Conclusions To increase the relaxation resistance and retain high values of strength and ductility of austempered reinforcing wire it is necessary to conduct tempering under stress at stresses somewhat lower than _0.01 and temperatures of 350–380°.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 32–33, August, 1979.     

Structure and mechanical properties of normalized low-pearlitic Mn-V steel

Conclusion An increase in sheet thickness during the normalization of steel 06G2AF from 12 to 80 mm gives rise to an approximate 15% reduction in the strength level (_0.2, _u); this is caused primarily by a change in the conditions of formation, the dimensions, and character of distribution of disperse vanadium carbonitrides in the ferritic matrix, and also by enlargement of the ferrite grain; the plasticity and semibrittleness temperature do not change in this case.Translated from Metallovedenie i Termicheskaya Obrabotkova Metallov, No. 12, pp. 19–22, December, 1985.