RESEARCH OF THE BORON INTERFACIAL DISTRIBUTION BETWEEN BORON-BEARING OXIDE AND METAL

The thermodynamic calculations have been performed to study the influence of silicon (0.1 – 0.8 %), aluminum (0.005 %) and carbon (0.1 %) contained in the metal on recovery process of boron from slag with the basicity equal to 5, at temperatures of 1400 – 1700 °C with the help of software package HSC 6.1 Chemistry (Outokumpu). The experiments of interfacial distribution of boron between slag system of СаО – SiО₂ – MgO – Al₂O₃ – B₂O₃ and metal have been carried out in a high temperature electrical resis­tance furnace of Tamman. The low-carbon steels with different con­tents of silicon were the base metal. The results of thermodynamic modeling and experimental data have shown that direct microalloy­ing of steel with boron are crucially possible due to boron reduce with the help of silicon in metal. The reduction of boron with slag is possible with the help of silicon in metal and the process was theo­retically based and experimentally studied. The results of thermody­namic modeling indicate the possibility of thermodynamic recovery of boron from the system of СаО – SiО₂ – MgO – Al₂O₃ – B₂O₃ with the help of silicon, despite its low (0.1 – 0.8 %) concentration in the metal. The increase of the initial silicon content in the steel increases the concentration of boron in the reduced metal. The results have shown the effect of silicon content and temperature of metal on the content of boron in steel. It has been shown that an extract of the metal by slag, containing 4.3 % B₂O₃ , is accompanied by boron reduction. The primary reductant of boron is silicon, whose content in the metal after the experiment is reduced by 15 – 22 %. Thus, the steel sample with high concentration of silicon contains greater amount of boron. Recovery rate of boron ranges from 5.8 to 6.9 %, it is essentially correlated with the results of thermodynamic mod­eling. The concentration of boron in the metal can be controlled by changing temperature of process and content of silicon in the steel. The research results can be used in the development of the process technology of direct steel microalloying with boron.

steel, slag, boron, thermodynamic modeling, experimental study, interfacial distribution of boron, direct alloying

1. Lyakishev N.P., Pliner Yu.L., Lappo S.I. Borsoderzhashchie stali i splavy [Boron-containing steels and alloys]. Moscow: Metallurgiya, 1986, 192 p. (In Russ.).

2. Ershov G.S., Bychkov Yu.B. Fiziko-khimicheskie osnovy ratsional’nogo legirovaniya stali i splavov [Physical and chemical frame¬works of rational alloying of steel and alloys]. Moscow: Metallur¬giya, 1982, 360 p. (In Russ.).

3. Heckmann C.J., Ormston D., Grimpe F. etc. Development of low carbon Nb-Ti-B microalloyed steels for high strength large diameter linepipe. Iron and Steelmaking. 2005, no. 4, pp. 57–60.

4. Asakhi Kh., Khaara T., Tzuru E. etc. Development of ultra-high-strength X120 UEO pipes. In: Sb. dokladov Mezhdunarodnogo sem¬inara “Sovremennye stali dlya gazonefteprovodnykh trub, problemy i perspektivy” [Collected papers of the International seminar “Modern steels for gas oil pipes, problems and perspectives”]. Moscow: Metallurgizdat, 2006, pp. 123–130. (In Russ.).

5. Kobyakov K.V., Nevar N.F. Research of the influence of alloying with boron on the properties of iron-carbon alloys. Lit’e i metallur¬giya. 2014, no. 1 (74), pp. 105–107. (In Russ.).

6. Gol’dshtein Ya.E., Mizin V.G. Modifitsirovanie i mikrolegirovanie chuguna i stali [Modification and microalloying of cast-iron and steel]. Moscow: Metallurgiya, 1986, 272 p. (In Russ.).

7. Kolbasnikov N.G., Matveev M.A. Research of boron influence on high-temperature plasticity of microalloyed steel. Nauch.-tekhn. vedomosti SPbGPU. Metallurgiya i materialovedenie. 2016, no. 1 (238), pp. 129–135. (In Russ.).

8. Potapov A.I. Issledovanie protsessov mikrolegirovaniya stali borom s tsel’yu sovershenstvovaniya tekhnologii proizvodstva borsoder¬zhashchei stali: Avtoref. dis. kand. tekhn. nauk [Research of pro¬cesses of steel microalloying with boron to improve the technology of production of boron-containing steel: Extended Abstract of Cand. Sci. Diss.]. Moscow, 2013, 27 p. (In Russ.).

9. Upadhyaya N., Pujara M.G., Sakthivelb T., Mallikaa C., Lahab K. and Kamachi Mudalia U. Effect of addition of boron and nitrogen on the corrosion resistance of modified 9Cr-1Mo ferritic steel. Pro¬cedia Engineering. 2014, no. 86, pp. 606–614.

10. Zhang Ya-long, Zhang Ying-yi1, Yang Fei-hua2, Zhang Zuo-tai. Ef¬fect of alloying elements (Sb, B) on recrystallization and oxidation of Mn-containing IF steel. Journal of iron and steel research, inter¬national. 2013, vol. 20, no. 3, pp. 39–44.

11. Wang H., Zhang T., Zhu H., Guirong L., Yongqi Y., Wang J. Effect of В2О3 on melting temperature, viscosity and desulfurization capacity of CaO-based refining flux. ISIJ International. 2011, vol. 51, no. 5, pp. 702–706.

12. Kyung Chul Choa, Dong Jun Munb, Yang Mo Koob, Jae Sang Leeb. Effect of niobium and titanium addition on the hot ductility of bo¬ron containing steel. Materials Science and Engineering A. 2011, vol. 528, pp. 3556–3561.

13. Loґpez-Chipresa E., Mejıґa I., Maldonado C., Bedolla-Jacuinde A., El-Wahabi M., Cabrera J.M. Hot flow behavior of boron microal¬loyed steels. Materials Science and Engineering A. 2008, vol. 480, pp. 49–55.

14. Stumpf W., Banks K. The hot working characteristics of boron bear¬ing and conventional low carbon steel. Materials Science and Engi¬neering A. 2006, vol. 418, pp. 86–94.

15. Stepanov A.I., Babenko A.A., Sychev A.V., Zhuchkov V.I., Murzin A.V., Dresvyankina L.E., Ushakov M.V. Development of technology for microalloying steel with boron using ferro-silicon-boron. Metallurgist. 2014, vol. 58, no. 7–8, pp. 588–590.

16. Bedolla-Jacuinde A., Guerra F.V., Rainforth M., Mejia I., Mal¬donado C. Sliding wear behavior of austempered ductile iron microalloyed with boron. Wear. May-June. 2015, vol. 330-331, pp. 23–31.

17. Konovalov R.P. Slitok kipyashchei stali [Open steel ingot]. Mos¬cow: Metallurgiya, 1986, 176 p. (In Russ.).

18. YANG Zhong-dong, LIU Su-lan, LI Ze-fu, XUE Xiang-xin. Oxidation of Silicon and Boron in Boron Containing Molten Iron. Jornal of iron and steel research, international. 2007, no. 14(6), pp. 32–36.

19. Zhuchkov V.I., Akberdin A.A., Vatolin N.A., Leont’ev L.I., Zaya¬kin O.V., Kim A.S. Usage of boron-containing materials in metal¬lurgy. Elektrometallurgiya. 2011, no. 3, pp. 25–29. (In Russ.).

20. Babenko A.A., Zhuchkov V.I., Smirnov L.A., Sychev A.V., Ak¬berdin A.A., Kim A.S., Vitushchenko M.F., Dobromilov A.A. Pro¬duction technology for low-carbon, low-sulfur boron steel. Steel in Translation. 2015, vol. 45, no. 11, pp. 883–886.

21. Roine A. Outokumpu HSC Chemistry for Windows. Chemical reac¬tions and Equilibrium software with extensive thermochemical data¬base. Pori: Outokumpu research OY, 2002.