ISSN 0967�0912, Steel in Translation, 2013, Vol. 43, No. 5, pp. 306–308. © Allerton Press, Inc., 2013.Original Russian Text © V.I. Zhuchkov, N.A. Andreev, O.V. Zayakin, Ya.I. Ostrovskii, V.I. Afanas’ev, 2013, published in “Stal’,” 2013, No. 5, pp. 36–37.

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Traditionally, which ferroalloys are produceddepends on the requirements expressed by consumers(mainly steel plants), the technological capabilities forferroalloy production, and the ore quality. In the lasthalf century, there have been significant changes insteel production. In particular, the introduction of fer�roalloys for alloying, reduction, and refining has beenswitched from the smelter to the ladle. That calls forcorresponding changes in ferroalloy characteristics,associated with the lower temperature in the ladle, thelimited time for interaction of the reagents, and so on.However, the chemical composition of the basic fer�roalloys has not changed since the 1950s. In addition,the range of ore used at Russian ferroalloy plants hasundergone significant changes in the past quarter cen�tury. Globally, lean chromium ores are found in 67% ofall deposits [1]. Already, many nations that producechrome ferroalloys are experiencing a shortage of orewith the required chemical and granulometric compo�sition. Every year, the discrepancy between metallur�gists’ increasing demand for chrome ferroalloys anddeclining reserves of rich chromium ore will rise.Accordingly, the use of lean ore (with <38–40% Cr2O3)is inevitable, in Russia and around the world. That willchange the composition (lower chromium content)and hence the characteristics of the ferroalloys pro�duced.

Accordingly, we must investigate the properties offerroalloys that meet the needs of steel producers andalso the best composition for such alloys.

At the Institute of Metallurgy, Ural Branch, Rus�sian Academy of Sciences, we have developed amethod of determining the best ferroalloy composi�tion on the basis of the correlation between the com�position and properties of the alloys [2]. Thatapproach includes two main stages: preliminary selec�tion of the elements in the ferroalloy in accordancewith the specified composition and properties of thesteel being produced; and determination of the basicelementary ratio by studying the physicochemicalcharacteristics of the ferroalloys and their interactionwith the ferrocarbon melt. The method takes account

of the basic factors that affect not only the smeltingand use of ferroalloys but also the properties of thesteel produced. In the present work, we study the mostsignificant physicochemical characteristics of chromeferroalloys: the melting point tm; and the density ρ.

The melting point is one of the main ferroalloyproperties. It is related to the rate and completeness ofassimilation of elements by the alloy. However, themelting range of high�carbon FKh800 ferrochrome is1500–1650°C according to the data of [3] and 1625–1674°C according to [4]. The melting point of ferroal�loys for steel treatment must be below the temperatureof the liquid metal (1550–1660°C).

The density of the ferroalloy affects its position andmotion in the melt and the rate and completeness ofassimilation of elements by the alloy. The recom�mended density of ferroalloys for steel treatment is 5–7 g/cm3 [2]. The density of commercial ferrochrome is6.75–7.3 g/cm3 for high�carbon alloys and 6.70–7.01 g/cm3 for low�carbon alloys [4]. For high�carbonferroalloy, the temperature at which melting ends cor�responds to 1490–1670°C for the liquidus and 1470–1620°C for the solidus; for low�carbon ferrochrome,these values are 1640–1670°C and 1540–1570°C,respectively [4].

To determine the influence of the ferroalloy com�position on its performance and its optimal composi�tion, we determine tm experimentally, by recording thetemperature curves on melt cooling, and determine ρby the pycnometric method. The table summarizes theresults.

In all the ferrochrome samples, we find that thephysicochemical characteristics are enhanced byreducing the chromium content and increasing the sil�icon content (within the stated limits). The best den�sity (5–7 g/cm3) is observed for all the alloys with ele�vated Si content (>5.3%), except alloy 10, whose den�sity is lower on account of the very high Si content(53.6%).

In Fe–Cr–Mn–Si–C alloys 11–17, the densitydoes not change markedly with variation in the

Composition and Performance of Chromium�Bearing FerroalloysV. I. Zhuchkova, N. A. Andreeva, O. V. Zayakina, Ya. I. Ostrovskiib, and V. I. Afanas’evb

aInstitute of Metallurgy, Ural Branch, Russian Academy of Sciences, Yekaterinburg, RussiabOAO Serovskii Zavod Ferrosplavov, Serov, Russia

Abstract—Experimental data on the composition, melting point, and density are presented for chromium�bearing ferroalloys: ferrochrome, ferrosilicochrome, and ferrochromomanganosilicon. The best composi�tions are determined for these ferroalloys.

DOI: 10.3103/S0967091213050240

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COMPOSITION AND PERFORMANCE OF CHROMIUM�BEARING FERROALLOYS 307

Mn content, but rises with increase in the Si content.Low�silicon alloy 14 is characterized by elevated den�sity; the other alloys have reasonable density. Thus, toreduce the density of both high� and low�carbonchrome alloys, an elevated Si content is required.

The melting point declines in proportion to theincrease in Si content in the alloys, while high�carbonferrochrome (alloy 1) and low�carbon ferrochrome(alloys 4–10) are characterized by reasonable meltingpoint with 5–54% Si.

In alloys 11–17, a sharp drop in the melting pointis observed. That may be attributed to the formation offusible manganese�silicide phases. All the alloys of thissystem have the recommended melting points.

The results for the ferroalloy properties are closelyrelated to the use of lean chromium ore. In manycountries, it is common practice to produce and usecharge chrome, with reduced Cr content (45–60%)and elevated Si content (3–10%) and with 6–8% C. In

Russia, this alloy is not in mass production, and hencethere are few literature data on its characteristics.

At OAO Serovskii Zavod Ferrosplavov, high�carbonferrochrome with reduced chromium content (chargecontent) is produced for commercial sale or for directuse in steel production, on the basis of lean Russianchromium ore (39% Cr2O3; 2.9% Si; 7.5% C). Thisproduct complies with the requirements in State Stan�dard GOST 4757–91 for FeCr50C70Si2LS high�car�bon ferrochrome. Research shows that its perfor�mance is better than that of high�chromium ferroalloy(>60% Cr).

In industrial trials, the smelting technology forfe rochromomanganosilicon containing ~40% Cr,~16% Mn, and ~12% Si has performed well [5]. Byorganizing the mass production of such complexchrome ferroalloys with manganese, lean Russianchromium and manganese ores may be processed andthe components Cr, Mn, and Si in standard ferroalloys

Chemical composition, %, and physicochemical characteristics of chrome ferroalloys

No. Cr Si C Mn ρ, g/cm3 °C °C

High�carbon ferrochrome

1 57.4 8.0 6.6 – 6.74 1516 1476

2 66.3 0.3 7.2 – 7.35 1676 1571

High�carbon ferrochrome and ferrosilicochrome

3 64.6 0.5 0.1 – – 1641 1555

4 61.8 5.3 0.1 – 7.01 1521 1465

5 57.8 10.0 0.1 – 6.82 1468 1368

6 51.4 18.7 0.1 – 6.50 1464 1375

7 46.2 26.5 0.1 – 6.41 1461 1370

8 41.9 32.3 0.1 – 5.60 1439 1370

9 35.6 42.0 0.1 – 5.38 1382 1308

10 29.2 53.6 0.1 – 4.69 1342 1261

Ferrochromomanganosilicon

11 37.0 11.3 0.1 22.3 6.84 1341 1262

12 33.9 9.1 0.2 31.6 6.93 1311 1262

13 45.0 10.1 0.1 12.0 6.91 1359 1271

14 39.4 2.3 0.2 24.4 7.31 1442 1393

15 38.3 15.9 0.1 17.8 6.03 1331 1277

16 38.4 10.4 0.1 22.3 6.79 1340 1275

17 34.6 9.5 0.2 20.1 6.755 1409 1369

Note: The balance consists of iron and impurities.

tmL

, tmS

,

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ZHUCHKOV et al.

may be replaced by a smaller quantity of cheaper com�plex ferroalloys.

Note, in conclusion, that steel producers are begin�ning to make wider use of chrome ferroalloys with ele�vated silicon content and reduced chromium contentand also complex alloys containing chromium, man�ganese, and silicon.

REFERENCES

1. Lyakishev, N.P. and Gasik, M.I., Metallurgiya khroma(Metallurgy of Chromium), Moscow: ELIZ, 1999.

2. Zhuchkov, V.I., Noskov, A.S., and Zav’yalov, A.L.,Determination of the optimal ferroalloy density by sim�

ulation, Izv. Vyssh. Uchebn. Zaved., Chern. Metall.,1981, no. 12, pp. 21–23.

3. Safiullin, R.B. and Bezobrazov, S.V., Melting points ofindustrial ferrochrome alloys, in Chernaya metallurgiya.Byull. Inst. Chermetinformatsiya (Ferrous Metallurgy:Bulletin of Chermetinformatsiya Institute), 1974,no. 19, pp. 46–47.

4. Mizin, V.G., Chirkov, N.A., and Ignat’ev, V.S., Ferro�splavy: sprav. izd. (Ferroalloys: A handbook), Moscow:Metallurgiya, 1992.

5. Druinskii, M.I. and Zhuchkov, V.I., Poluchenie komple�ksnykh ferrosplavov iz mineral’nogo syr’ya Kazakhstana(Production of Complex Alloys from Minerals Minedin Kazakhstan), Alma�Ata: Nauka, KazSSR, 1988.

Translated by B. Gilbert