페라이트-펄라이트 조직 저탄소강의 미세조직과 인장 특성의 상관관계에 미치는 미량합금원소와 변태 온도의 영향

이상인; 이지민; 황병철; Sang-In Lee; Ji-Min Lee; Byoungchul Hwang

Korean Journal of Materials Research, Vol.27, No.4, 184-191, April, 2017

DOI10.3740/MRSK.2017.27.4.184 Export Citation

페라이트-펄라이트 조직 저탄소강의 미세조직과 인장 특성의 상관관계에 미치는 미량합금원소와 변태 온도의 영향

Effect of Micro-Alloying Elements and Transformation Temperature on the Correlation of Microstructure and Tensile Properties of Low-Carbon Steels with Ferrite-Pearlite Microstructure

이상인, 이지민, 황병철 ^†

서울과학기술대학교 신소재공학과

Sang-In Lee, Ji-Min Lee, and Byoungchul Hwang^†

Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 01811, Korea

E-mail:

This present study deals with the effect of micro-alloying elements and transformation temperature on the correlation of microstructure and tensile properties of low-carbon steels with ferrite-pearlite microstructure. Six kinds of lowcarbon steel specimens were fabricated by adding micro-alloying elements of Nb, Ti and V, and by varying isothermal transformation temperature. Ferrite grain size of the specimens containing mirco-alloying elements was smaller than that of the Base specimens because of pinning effect by the precipitates of carbonitrides at austenite grain boundaries. The pearlite interlamellar spacing and cementite thickness decreased with decreasing transformation temperature, while the pearlite volume fraction was hardly affected by micro-alloying elements and transformation temperature. The room-temperature tensile test results showed that the yield strength increased mostly with decreasing ferrite grain size and elongation was slightly improved as the ferrite grain size and pearlite interlamellar spacing decreased. All the specimens exhibited a discontinuous yielding behavior and the yield point elongation of the Nb4 and TiNbV specimens containing micro-alloying elements was larger than that of the Base specimens, presumably due to repetitive pinning and release of dislocation by the fine precipitates of carbonitrides.

Keywords:tensile properties;low-carbon steels;micro-alloying elements;transformation temperature;yield point elongation.

[References]

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Li L, Liu S, Ye B, Hu S, Zhou Z, Met. Mater. Int., 22, 391 (2016)
Hwang JK, son IH, Yoo JY, Zargaran A, Kim NJ, Met. Mater. Int., 21, 815 (2015)
Han J, da Silva AK, Ponge D, Raabe D, Lee SM, Lee YK, Lee SI, Hwang B, Acta Mater., 122, 199 (2017)
Han J, Lee YK, Acta Mater., 67, 354 (2014)
Wang M, Zhang F, Yang Z, Mater Des., 114, 102 (2017)
Tsuchida N, Inoue T, Nakano H, Okamoto T, Mater. Lett., 160, 117 (2015)
Miyamoto G, Karube Y, Furuhara T, Acta Mater., 103, 370 (2016)
Deng X, Fu T, Wang Z, Liu G, Wang G, Misra RDK, Met. Mater. Int., 23, 175 (2017)
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Kang KB, Kwon O, Lee WB, Park CG, Scr. Mater., 36, 1303 (1997)
Hansen SS, Vander Sande JB, Cohen M, Metall. Mater. Trans. A-Phys. Metall. Mater. Sci., 11, 387 (1980)
O'Donnelly BE, Reuben RL, Baker TN, Met. Technol., 11, 45 (1984)
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Lee SY, Lee SI, Hwang B, Korea J. Met. Mater., 54, 637 (2016)
Miller LE, Smith GC, J. Iron Steel Inst., 208, 998 (1970)
Dieter GE, Bacon D, Mechanical Metallurgy, ed. Bacon D, McGraw-Hill (1988).

[Related Articles]

[1] Jung JE, Park J, Kim JS, Jeon JB, Kim SK, Chang YW, Met. Mater. Int., 20, 27 (2014)

[2] Li L, Liu S, Ye B, Hu S, Zhou Z, Met. Mater. Int., 22, 391 (2016)

[3] Hwang JK, son IH, Yoo JY, Zargaran A, Kim NJ, Met. Mater. Int., 21, 815 (2015)

[4] Han J, da Silva AK, Ponge D, Raabe D, Lee SM, Lee YK, Lee SI, Hwang B, Acta Mater., 122, 199 (2017)

[5] Han J, Lee YK, Acta Mater., 67, 354 (2014)

[6] Wang M, Zhang F, Yang Z, Mater Des., 114, 102 (2017)

[7] Tsuchida N, Inoue T, Nakano H, Okamoto T, Mater. Lett., 160, 117 (2015)

[8] Miyamoto G, Karube Y, Furuhara T, Acta Mater., 103, 370 (2016)

[9] Deng X, Fu T, Wang Z, Liu G, Wang G, Misra RDK, Met. Mater. Int., 23, 175 (2017)

[10] Pickering FB, Garbarz B, Scripta Metallurgica, 21, 249 (1987)

[11] Gladman T, Mcivor ID, Pickering FB, J. Iron Steel Inst., 210, 916 (1972)

[12] Zener C, Holloman JH, J. Appl. Phys., 15, 22 (1944)

[13] Kang KB, Kwon O, Lee WB, Park CG, Scr. Mater., 36, 1303 (1997)

[14] Hansen SS, Vander Sande JB, Cohen M, Metall. Mater. Trans. A-Phys. Metall. Mater. Sci., 11, 387 (1980)

[15] O'Donnelly BE, Reuben RL, Baker TN, Met. Technol., 11, 45 (1984)

[16] De Cooman BC, Materials Design: The Key to Modern Steel Products, Grips Media (2007).

[17] Lee SY, Lee SI, Hwang B, Korea J. Met. Mater., 54, 637 (2016)

[18] Miller LE, Smith GC, J. Iron Steel Inst., 208, 998 (1970)

[19] Dieter GE, Bacon D, Mechanical Metallurgy, ed. Bacon D, McGraw-Hill (1988).