Strengthening in the pearlite of 0·75C–1·2Mn (wt-%) steels resulting from microalloying with 0·09–0·16% V was examined. The steels were transformed by controlled cooling in a dilatometer at an average transformation temperature of 600°C, which produced a pearlite interlamellar spacing of 0·11–0·12 μm. Using electron microscopy no hardening precipitates in the as transformed specimens were revealed, but after additional aging V(CN) precipitates were observed. In the investigation of the hardening caused by V(CN) precipitation, a limiting value was found, which could not be increased by a further addition of V. The limit of the precipitation hardening is suggested to be a consequence of the limited amount of C and N dissolved in the ferrite, since no interphase precipitation occurred. The maximum hardness obtained was 400 HV20 and an increment of 75 HV20 (or 260 MN m−2 in strength) was found in comparison with the comparable pearlite structure of a steel containing no V. From examination of the effect of the thermomechanically processed austenite structure on the pearlite morphology, it was found that transformation from fine grained unrecrystrallised austenite produced an ultrafine colony pearlite from which it can be stated that this transformation would result in improved toughness in pearlitic steels.
MST/847
Get full access to this article
View all access options for this article.
References
1.
GLADMANT., McIVORI. D., and PICKERINGF. B.: J. Iron Steel Inst.,1972, 210, 916–930.
2.
THEWLISG. and NAYLORD. J.: Met. Mater., Dec. 1981, 21-28.
3.
ENGINEERS. and STEINENA. VON DEN: Thyssen Edelstahl Tech. Ber.,1980, 6, (2), 85–89.
DUNLOPG. L., CARLSSONC. J., and FRIMODIGG.: Metall. Trans.,1978,9A, 261–266.
6.
PARSONSS. A. and EDMONDSD. V.: Mater. Sci. Technol.,1987, 3, 894–904.
7.
SCHMEDDERSH.: in ‘Vanadium in rail steels’, A1—A25; 1979, London, VANITEC.
8.
SAGEA. M., HODGSONW., and STONED. H.: in ‘Vanadium in rail steels’, BI—B21; 1979, London, VANITEC.
9.
RIDLEYN., LEWISM. T., and MORRISONW. B.: in ‘Advances in the physical metallurgy and applications of steels’,199–205; 1982, London,The Metals Society.
10.
HELLERW., SCHWEITZERR., and WEBERL.: Can. Metall. Q.,1982, 21, 3–15.
11.
PARSONSD. E., MUNROD. A., and NG-YELIMJ.: Can. Metall. Q.,1983, 22, 475–483.
12.
LAUFERE. E. and FEGREDOD. M.: Can. Metall. Q.,1983, 22, 193–203.
13.
PARSONSD. E., MALIST. F., and BOYDJ. D.: in I-ISLA steels — Technology and applications’, (ed. KorchynskyM., 1129-1135; 1984, Metals Park, OH, ASM.
14.
NYB.. CORDON, P. TIMINEY, T. D. MOTTISHAW, and G. D. W. SMITH: in ‘Developments in the drawing of metals’, 228-234; 1983, London, The Metals Society.
15.
MOTTISHAWT. D. and SMITHG. D. W.: in LISLA steels — Technology and applications’, (ed. KorchynskyM., 163-175; 1984, Metals Park, OH, ASM.
16.
JAISWALS. and McIVORI. D.: Mater. Sci. Technol.,1985, 1, 276–284.
17.
GUERRIERIA., MASCANZONIA., and MAZZUCATOF.: Metall. Ital.,1982, 74, 751–771.
18.
YADAH., MURAKAMIM., OCHIAIM., MORIT., and TOMINAGAJ.: Nippon Steel Tech. Rep., June 1983, (21), 203-215.
19.
VAROR. A.: in Proc. 2nd Int. Conf. on ‘Steel rolling’, Dusseldorf, June 1984, VDEh—CRM, paper CIN.
20.
BERCYP., BOELU. G., LAMBERTN., and ECONOMOPOULOSM.: Metall. Plant Technol.,1984, 4, 46–51.
21.
PICKERINGF. B.: in ‘Towards improved ductility and toughness’, 9-31; 1971, London, Climax Molybdenum.
22.
PICKERINGF. B.: in ‘Hardenability concepts with applications to steel’, (ed. DoaneD. V. and KirkaldyJ. S.), 179-225; 1978, New York, AIME.
23.
MARDERA. R. and BRAMFITTB. L.: Metall. Trans.,1976, 7A, 365–372.
24.
ITYZAKJ. M. and BERNSTEINI. M.: Metall. Trans.,1976, 7A, 1217–1224.
25.
DOLLARM., BERNSTEINI. M., and THOMPSONA. W.: ‘Influence of deformation substructure on flow and fracture of fully pearlitic steel’, Carnegie Mellon University, Pittsburgh, PA, 1986.
26.
GARBARZB. and PICKERINGF. B.: Mater. Sci. Technol.,1988, 4, 328–334.
27.
LEWANDOWSKIJ. J. and THOMPSONA. W.: Metall. Trans.,1986, 17A, 461–472.
28.
KAVISHEF. P. L. and BAKERT. J.: Mater. Sci. Technol.,1986, 2, 816–822.
29.
PICKERINGF. B. and GARBARZB.: Scr. Metall.,1987, 21, 249–253.
30.
PARKY. J. and BERNSTEINI. M.: in ‘Fracture 1977’, (ed. TaplinD. M. R.), Vol. 2, 33-40; 1977, Waterloo, Ont., University of Waterloo Press.
31.
PARKY. J. and BERNSTEINI. H.: Metall. Trans.,1979, 10A, 1653–1664.
32.
ALEXANDERD. J. and BERNSTEINI. M.: Metall. Trans.,1982, 13A, 1865–1868.
33.
BERNSHTEINM. L., VLADIMIRSKAYAT. K., ZAYMOVSKIV. A., KAPUTKINAL. M., MOROZOVAT. I., PICKEIELAURIN. N., and SAMEDOVO. V.: Izv. Akad. Nauk SSSR, Met.,1979, (2), 130-139.
34.
UMEMOTOM., OHTSUKAH., and TAMURAI.: Trans. Iron Steel Inst. Jpn.,1983, 23, 775–784.
35.
KESTENBACHH. J. and MARTINSG. S.: Metall. Trans.,1984, 15A, 1496–1499.
36.
WADAT., FUKUDAK., and TAIRAT.: Trans. Iron Steel. Inst. Jpn, 1984,24, B277.
ROBERTSW.: in ‘FISLA steels — Technology and applications’, (ed. KorchynskyM., 33-65; 1984, Metals Park, OH, ASM.
39.
ZHENGY., DEARDOA. J., FIXR. M., and FITZSIMONSG.: in IISLA steels —Technology and applications’, (ed. KorchynskyM., 85-94; 1984, Metals Park, OH, ASM.
40.
SIWECKIT., SANDBERGA., and ROBERTSW.: in ‘IISLA steels — Technology and applications’, (ed. KorchynskyM., 619-634; 1984, Metals Park, OH, ASM.
41.
FIXR. M., DEARDOA. J., and ZHENGY.: in ‘IISLA steels — Metallurgy and applications’, (ed. GrayJ. M. et al.), 219–227; 1986, Metals Park, OH, ASM International.
42.
BAKERR. G. and NUTTINGJ.: in ‘Precipitation processes in steels’, 1-22; 1959, London, The Iron and Steel Institute.
43.
RICKSR. A., PARSONSS. A., and HOWELLP. R.: in ‘Solid—solid phase transformation’, (ed. AaronsonH. I. et al), 831-835; 1982, Warrendale, Pa, The Metallurgical Society of AIME.
44.
CAHNJ. W. and MAGEEW. C. in ‘Decomposition of austenite by diffusional processes’, (ed. ZackayV. F. and AaronsonH. I.), 131–192; 1962, New York, Interscience.
45.
RAZIKN. A., LORIMERG. W., and RIDLEYN.: Acta Metall., 1974,22, 1249–1258.
46.
RIDLEYN.: in ‘Solid—solid phase transformation’, (ed. AaronsonH. I. et al.), 807–811; 1982, Warrendale, PA, The Metallurgical Society of AIME.
47.
AL-SALMANS. A., LORIMERG. W., and RIDLEYN.: Metall. Trans.,1979, 10A, 1703–1709.
48.
RIDLEYN.: Can. Metall. Q.,1983, 22, 807–811.
49.
VELANDERK., LEHTINENB., and SANDBERGO.: ‘Vanadium-microalloyed steels for wire rod’, Swedish Institute for Metals Research, Stockholm, 1986.
50.
UNDERWOODE. E.: in ‘Quantitative microscopy’, (ed. deR. T.Hoff and F. N. Rhines), 77-127; 1968, New York, McGraw-Hill.
51.
VOORTG. F. VANDER and ROOSZA.: Metallography, 1984, 17, 1–17.
52.
BAINE. C. and PAXTONH. W.: ‘Alloying elements in steel’, 107-112; 1966, Metals Park, OH, ASM.
53.
NILSSONH.: ‘Vanadium-microalloyed eutectoid steels’, Swedish Institute for Metals Research, Stockholm, 1986.
54.
HACKNEYS. A. and SHIFLETG. J.: Acta Metall., 1987, 35, 1019–1028.
55.
RIDLEYN.: in ‘Phase transformations in ferrous alloys’, (ed. MarderA. R. and GoldsteinJ. I.), 201-236; 1984, New York, AIME.
56.
ATKINSM.: ‘Atlas of continuous cooling transformation diagrams for engineering steels’; 1977, Sheffield, British Steel Corporation.
57.
DARKENL. S. and FISHERR. M.: in ‘Decomposition of austenite by diffusional processes’, (ed. ZackayV. F. and AaronsonH. I.), 249-288; 1962, New York, Interscience.
