Abstract
The effect of different microstructures on the fatigue behaviour of a medium carbon vanadium microalloyed steel has been studied. Specimens were subjected to a controlled closed die forging followed by cooling in sand, air or oil, respectively. The hardness and fatigue properties of the microalloyed steel are determined and compared with those of ferrite-pearlite and martensite microstructures obtained by cooling with different mediums after forging. Relatively fine ferrite and pearlite increase the fatigue strength of the steel, while the martensite structure reduces the fatigue strength. Characteristics of fatigue fracture surface morphology are summarized and related to fatigue crack initiation and propagation mechanisms in the forged medium carbon microalloyed steel. The cooling rate has a remarkable effect on the microstructure, hardness, and fatigue behaviour at room temperature.
Kurzfassung
Für den vorliegenden Beitrag wurde der Effekt verschiedener Gefüge auf das Ermüdungsverhalten eines mikrolegierten vanadiumhaltigen Stahls mit mittlerem Kohlenstoffgehalt untersucht. Hierzu wurden Proben einem kontrollierten und geschlossenen Gesenkschmiedeprozess unterworfen, gefolgt von Abkühlen in Sand, Wasser bzw. Öl. Die Härte und die Ermüdungseigenschaften des mikrolegierten Stahls wurden bestimmt und mit denen ferritisch-perlitischer und martensitischer Gefüge nach Abkühlung in verschiedenen Medien verglichen. Relativ feiner Ferrit und Perlit erhöhen, im Gegensatz zur martensitischen Struktur, die Ermüdungsfestigkeit des Stahls. Es werden außerdem die Chrakteristika der Oberflächenmorphologie der Ermüdungsbrüche gesammelt und der Zusammenhang zu den Mechanismen der Initiierung und des Fortschrittes der Ermüdungsrisse in dem geschmiedeten mikrolegierten Stahl mit mittlerem Kohlenstoffgehalt untersucht. Die Abkühlrate hat einen bemerkenswerten Effekt auf das Gefüge, die Härte und das Ermüdungsverhalten bei Raumtemperatur.
References
1 K. A.Padmanabhana, S.Sankaranb: Fatigue behaviour of a multiphase medium carbon V-bearing microalloyed steel processed through two thermomechanical routes, J. Mater. Process. Technol.207 (2008), pp. 293–30010.1016/j.jmatprotec.2008.06.052Search in Google Scholar
2 D. K.Matlock, G.Krauss, J. G.Speer: Microstructures and properties of direct-cooled microalloy forging steels, J. Mater. Process. Technol.117 (2001), pp. 324–32810.1016/S0924-0136(01)00792-0Search in Google Scholar
3 L.Yang, A.Fatemi, D. A.Rhoda, J. E.Tripp: An overview of microalloyed steel, part I: metallurgical aspects, 77th SAE International Congress and Exposition, Detroit, Michigan (1996), Technical paper series 960308 10.4271/960308Search in Google Scholar
4 S.Shanmugama, R. D. K.Misra, T.Mannering, D.Panda, S. G.Jansto: Impact toughness and microstructure relationship in niobium and vanadium microalloyed steels processed with varied cooling rates to similar yield strength, Mater. Sci. Eng. A437 (2006), pp. 436–44510.1016/j.msea.2006.08.007Search in Google Scholar
5 R.Anumolu, R. B.Kumar, R. D. K.Misra, T.Mannering, D.Panda, S. G.Jansto: On the determining role of microstructure of niobiummicroalloyed steels with differences in impact toughness, Mater. Sci. Eng. A491 (2008), pp. 55–61Search in Google Scholar
6 D. F.Lauritoa, C. A. R. P.Baptistaa, M. A. S.Torresb, A. J.Abdallac: Microstructural effects on fatigue crack growth behaviour of a microalloyed steel, Procedia Eng.2 (2010), pp. 1915–192510.1016/j.proeng.2010.03.206Search in Google Scholar
7 B. K.Panigrahi: Processing of low carbon steel plate and hot strip – An overview, Mater. Sci.24 (2001), pp. 361–37110.1007/BF02708632Search in Google Scholar
8 S. N.Prasad, D. S.Sarma: Influence of thermomechanical treatment on microstructure and mechanical properties of a microalloyed (Nb+V) weather-resistant steel, Mater. Sci. Eng. A399 (2005), pp. 161–172Search in Google Scholar
9 A.Ghosh, B.Mishra, S.Das, S.Chatterjee: An ultra low carbon Cu bearing steel: Influence of thermomechanical processing and aging heat treatment on structure and properties, Mater. Sci. Eng. A374 (2004), pp. 43–5510.1016/j.msea.2003.11.047Search in Google Scholar
10 A.Ghosh, S.Das, S.Chatterjee, B.Mishra, P.Ramachandra Rao: Influence of thermo-mechanical processing and different post-cooling techniques on structure and properties of an ultra low carbon Cu bearing HSLA forging, Mater. Sci. Eng. A348 (2003), pp. 299–30810.1016/S0921-5093(02)00735-9Search in Google Scholar
11 A.Ghosh, S.Das, S.Chatterjee, P.Ramachandra: Effect of cooling rate on structure and properties of an ultra-low carbon HSLA-100 grade steel, Mater. Character.56 (2006), pp. 59–6510.1016/j.matchar.2005.09.014Search in Google Scholar
12 P. C. M.Rodrigues, E. V.Pereloma, D. B.Santos: Mechanical properties of an HSLA bainitic steel subjected to controlled rolling with accelerated cooling, Mater. Sci. Eng. A283 (2000), pp. 136–143Search in Google Scholar
13 T.El-Bitar, N.Fouadb, A. I.Zakya, S. A.El-Radyb: Effect of cooling rate after controlled forging on properties of low carbon multi-microalloyed steels, Mater. Sci. Eng. A534 (2012), pp. 514–52010.1016/j.msea.2011.11.101Search in Google Scholar
14 B. K.Show, R.Veerababu, R.Balamuralikrishnan, G.Malakondaiah: Effect of vanadium and titanium modification on the microstructure and mechanical properties of a microalloyed HSLA steel, Mater. Sci. Eng. A527 (2010), pp. 1595–160410.1016/j.msea.2009.10.049Search in Google Scholar
15 S.Sankaran, V.Subramanya Sarma, K. A.Padmanabhan: Low cycle fatigue behaviour of a multiphase microalloyed medium carbon steel: Comparison between ferrite/pearlite and quenched and tempered microstructures, Mater. Sci. Eng. A345 (2003), pp. 328–33510.1016/S0921-5093(02)00511-7Search in Google Scholar
16 M.Jahazi, B.Eghbali: The influence of hot forging conditions on the microstructure and mechanical properties of two microalloyed steels, J. Mater. Process. Technol.113 (2001), pp. 594–59810.1016/S0924-0136(01)00599-4Search in Google Scholar
17 D. R.Askeland: The Science and Engineering of Materials, Chapmen and Hall, London, UK (1996)10.1007/978-1-4899-2895-5Search in Google Scholar
18 I.Madariage, I.Gutierrez, A. C.Garcia-de, C.Capdevila: Acicular ferrite formation in a medium carbon steel with a two stage continuous cooling, Scripta Mater.41 (1999), pp. 229–23510.1016/S1359-6462(99)00149-9Search in Google Scholar
19 F.Penalba, C.Garcia De Andres, M.Carsi, F.Zapirain: Austenite grain size evolution and continuous cooling transformation diagrams in vanadium and titanium microalloyed steels, J. Mater. Sci.31 (1996), pp. 3847–3852Search in Google Scholar
20 R. W.Honeycombe, H. K.Bahadeshia: Steels: Microstructure and Properties, Gray Publishing, UK (1995)Search in Google Scholar
21 A.Babakhani, S. M. R.Ziaei, A. R.Kiani-Rashid: Investigation on the effects of hot forging parameters on the austenite grain size of vanadium microalloyed forging steel (30MSV6), J. Alloys Comp.490 (2010), pp. 572–57510.1016/j.jallcom.2009.10.083Search in Google Scholar
22 S.Gündüz, R. C.Cochrane: Influence of cooling rate and tempering on precipitation and hardness of vanadium microalloyed steel, Mater. Des.26 (2005), pp. 486–492Search in Google Scholar
23 M. A.Bepari: Effect of precipitation on strength and toughness of vanadium structural steels, Mater. Sci. Technol.6 (1990), pp. 338–34810.1179/026708390790190937Search in Google Scholar
24 S.Gündüz, R. C.Cochrane: Clustering effect on high temperature tensile behaviour of vanadium microalloyed steel, J. Mater. Process. Technol.186 (2007), pp. 246–252Search in Google Scholar
25 D.Rasouli, Sh.Khameneh Asl, A.Akbarzadeh, G. H.Daneshi: Effect of cooling rate on the microstructure and mechanical properties of microalloyed forging steel, J. Mater. Process. Technol.206 (2008), pp. 92–9810.1016/j.jmatprotec.2007.12.006Search in Google Scholar
26 N.Ridley, M. T.Lewis, W. B.Morrison: Advances in Physical Metallurgy and Applications of Steels, Metal Society, London, UK (1982)Search in Google Scholar
27 A. M.Sage: An overview of the use of microalloys in HSLA steels with particular reference to vanadium and titanium, G.Tither, Z.Shouhua (Eds.): HSLA Steels: Processing, Properties and Applications, The Minerals, Metals and Materials Society (1992), pp. 51–68Search in Google Scholar
28 A.Kaynar, S.Gündüz, M.Türkmen: Investigation on the behaviour of medium carbon and vanadium microalloyed steels by hot forging test, Mater. Des.51 (2013), pp. 819–825Search in Google Scholar
29 M. D.Chapetti, T.Tagava, T.Miyata: Ultra-long cycle fatigue of high strength carbon steels, PartII: Estimation of fatigue limit for failure from internal inclusions, Mater. Sci. Eng. A356 (2003), pp. 236–24410.1016/S0921-5093(03)00136-9Search in Google Scholar
30 Y.Zhong, Y.Shan, F.Xiao, KeYang: Effect of toughness on low cycle fatigue behaviour of pipeline steels, Mater. Lett.59 (2005), pp. 1780–178410.1016/j.matlet.2005.01.066Search in Google Scholar
31 D. Y.Wei, J. L.Gu, H. S.Fang, B. Z.Bai, Z. G.Yang: Fatigue behaviour of 1500 MPa bainite/martensite duplex-phase high strength steel, International Journal of Fatigue26 (2004), pp. 437–44210.1016/j.ijfatigue.2003.06.003Search in Google Scholar
32 M.Bahmani, R.Elliot: The relationship between fatigue strength and microstructure in an austempered Cu-Ni-Mn-Mo alloyed ductile iron, J Mater. Sci.32 (1997), pp. 5383–5388Search in Google Scholar
33 P. C.Chakraborti, M. K.Mitra: Room temperature low cycle fatigue behaviour of two high strength lamellar duplex ferrite-martensite (DFM) steels, Int J. Fatig.27 (2005), pp. 511–51810.1016/j.ijfatigue.2004.09.003Search in Google Scholar
34 R.Idris, Y.Prawoto: Influence of ferrite fraction within martensite matrix on fatigue crack propagation: An experimental verification with dual phase steel, Mater. Sci. Eng. A552 (2012), pp. 547–55410.1016/j.msea.2012.05.085Search in Google Scholar
35 F.Iacoviello: Microstructure influence on fatigue crack propagation in sintered stainless steels, Int. J. Fatigue27 (2005), pp. 155–16310.1016/j.ijfatigue.2004.06.003Search in Google Scholar
© 2013, Carl Hanser Verlag, München
