[en] The method of melting vanadium-containing steels in acid open-hearth furnaces is suggested which includes the introduction of vanadium slag with combination of silicon-carbide abrasive and chamotte. The method has the purpose to increase furnace productivity and to save charge meterials. The peculiar feature of the method consists of correction of slag composition through a manganese monoxide content in the initial stage of metal boiling. Preset carbon content being reached the metal is deoxidized with manganese, alloyed with chromium, tapped and casted

No abstract available

[en] The method of melting vanadium-containing steel in Martin and arc furnaces is suggested with the purpose to decrease rejects and improve mechanical properties of the steel. The method includes preliminary reduction, vanadium alloying and final reduction of the steel using combined ferrovanadium-silicon alloying composition. 40-60% of the alloying composition amount is introduced 1 alloying composition amount is introduced 15-20 min before steel tapping, the rest is added directly to a casting ladle. The method suggested allows to receive a saving of 3.64 roubles per ton of vanadium-containing steel

[en] Biaxial low cycle fatigue tests at various temperatures and strain rates were performed on 1% Cr-Mo-V steel and AISI 316 stainless steel under combined torsional and axial loads. A correlation for fatigue strength has been derived, and it is also shown that if the Gough ellipse quadrant criterion is rephrased in terms of strain amplitudes, it may be used as a safe design rule for ductile metals in both the low and high cycle fatigue regimes. (author)

No abstract available

[en] Hard turning was carried out on an X37CrMoV5-1 hot work tool steel with a hardness of 50 ± 2 HRC on a computer numerical control lathe, using a ceramic insert without the use of a coolant. The cutting parameters included three different cutting speeds, three different feed rates, and three different cutting depths. A full factorial design (FFD) was created, and 3${}^3$=27 experiments were carried out. The effects of cutting parameters on cutting force (Fc), surface roughness (Ra), material removal rate (MRR), specific cutting energy (SCE), current (Cu), and sound intensity (SI) were investigated. As a result of the analysis of variance (ANOVA), the effect ratios of cutting parameters on Fc, Ra, MRR, SCE, Cu, and SI were examined, and important parameters were determined. As a result, the effective rates of the feed rate, which is the most effective parameter, on Fc, Ra, and MRR were determined as 61.72, 95.90, and 61.70%, respectively. The cutting depth was 54.81 and 34.37% on SCE and SI, respectively, and the cutting speed was effective on Cu by 79.87%. By using FFD and response surface methodology (RSM), the regression equations of the results of Fc, Ra, MRR, SCE, Cu, and SI were extracted, and r${}^2$ values were examined. In the validation experiments performed after the optimization experiments, the experimental results were estimated using FFD, RSM, and Taguchi method, and the differences between them were analyzed.

[en] This work analyses the medium carbon micro alloyed vanadium potential for closed die forged production. The steels reach the mechanical resistance requests during cooling after forging, eliminating the subsequent thermal treatment. Those steels also present good fatigue resistance and machinability. The industrial scale experiments are also reported

[en] The nature of dynamic recrystallization stress strain curves was studied following an increase or decrease in strain rate after deformation into the steady state region. For this purpose, a vanadium microalloyed steel was hot compressed at constant true strain rates of 5.6 x 10^-5s^-1 to 7.4 x 10^-2s^-1 at a testing temperature of 1000 C. After an increase in strain rate, the flow curve displayed a single peak; the strain and in this case was distinctly smaller than that associated with the annealed structure. After a decrease in strain rate, by contrast, the flow curve displayed a multiple peak: under these conditions and' /SUB p/ was nearly equal to that for the annealed structure. The transients observed after a strain rate change were of the inverse type, thus differing sharply from those observed when dynamic recovery is rate controlling. The critical condition at which the shape of the stress-strain curve changed from the multiple to the single peak type was D /SUB x1/ , = D /SUB x2/ . (Here D /SUB s1/ and D /SUB s2/ are the stable dynamically recrystallized grain sizes before and after the change in strain rate, respectively.) This differs from the critical condition for the annealed structure, i.e. D /SUB o/ = 2D /SUB v/ where D /SUB o/ and D /SUB v/ are the initial and stable grain sizes. These results are interpreted in terms of a grain size based model for dynamic recrystallization

[en] Peculiarities of the formation of primary orientations as a result of hot and subsequent cold rolling in the Ti-V α-alloys are studied. The texture has been studied using the X-ray method with an aid of direct polar figures of the (0002) and (1010) planes. It is shown that as a result of rolling at 800 deg C in the alloys, containing up to 2% V, the texture of the basic central type (0001) [1010] with a higher dispersion in the transverse direction, than in the direction of rolling, is formed. With the increase of vanadium concentration in the alloy the dispersion in the transverse direction decreases. The texture of the cold rolling in the Ti-V alloys after deformation with the compression of more than 60% is monocomponent and is presented as (0001)+-α-HH-PH-[1010]. The α angle increases with the growth of vanadium content in the alloy from 30 deg for pure titanium to 37 deg for the Ti-2% V alloy (epsilon=80 %)

[en] The influence of slow temperature changes on the creep of CrMoV steel was measured in a test. At the same time tests were carried out under constant temperature conditions in order to have possibilities of comparison. With the help of two extrapolation methods developed by Dorn and Larson-Miller, an attempt was made to predict the behaviour of the tested steel under changing temperatures. (orig.)