Effect of Heat Treatment and Bake Hardening on the Mechanical Properties and Microstructure of Dual Phase Steel

Abbas Abdul Hussein Abid; Abbas Fadhil Abbas

doi:10.24237/djes.2019.12310

Authors

Abbas Abdul Hussein Abid
abbasaltaee@yahoo.com
Department of Mechanical Engineering, College of Engineering, Baghdad University, Baghdad, Iraq
Abbas Fadhil Abbas Department of Mechanical Engineering, College of Engineering, Baghdad University, Baghdad, Iraq

Keywords:

intercritical annealing, dual phase steel, tensile properties, hardness

Abstract

This research is concerned with study of the effect heat treatment and the bake hardening process on dual phase steels which can be obtain by intercritical annealing process. Hardness, microstructure and tensile specimens were prepared according to standards. Used specimens was with different carbon content (0.12, 0.096 and 0.064). The normalizing heat treatment was conducted on low carbon steel, to remove the effect of the previous manufacturing processes. Intercritical annealing was used as a heat treatment to obtain the dual phase steel, the carbon steel was quenched from760 ºC this temperature lies between the critical points. It has been found that after intercritical annealing process has transformation accrue from pearlite structure resulting from the normalization process to a new structure contain ferrite and martensite. The hardness of dual-phase steel obtained by intercritical annealing is higher than of the steel that was normalized as well as the carbon content of the steel affects the hardness. Tensile test results showed that the ultimate tensile strength and yield strength increased after intercritical annealing process compared to other specimens were normalized ,content of carbon also effect on the ultimate tensile strength and yield point. The dual phase steel is characterized with no visible yield point due to the dislocations movement are restricted. Dual phase steel yield point re-appear after pre-strained at 3, 5, 8, 10%., and baked to 170 ° C. The ultimate tensile strength and the yield point for the pre-strained and baked specimens were higher than the other tensile specimens which conducted with normalizing or intercritical annealing only due to the diffused carbon atoms that pin dislocations and prevent it is movement. Baking process is affected by several factors such as carbon ratio and the amount of prestrain. It is found that when carbon content increase, the number of diffused carbon atoms will increase. Amount of pre-strain effect on the mechanical properties after baking process, where it was found that when the mount of pre-strain increase the ultimate tensile strength and yield point stress will increase

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References

. D. Westerbaan, W. Xua, S. S. Nayak, DL. Chen, F. Goodwin, Y. zhou, “Tensile and fatigue properties of fiber laser welded high strength low alloy and DP980 dual-phase steel joints” Materials and Design 43 (2013) 373–3.

. Adeolu Adesoji, ADEDIRAN, Muhammed Olalekan Hakeem AMUDA, Sunday ARIBO,“Mechanical properties of dual phase steel quenched in bitumenmedium ”Leonardo Electronic Journal of Practices and TechnologiesISSN 1583-1078Issue 26, January-June 2015, p. 1-16.

. H. Ghassemi-Armaki, R. Maaß., S.P. Bhat, S. Sriram, J. R. Greer, K. S. Kumar “Deformation response of ferrite and martensite in a dual-phase steel”. Acta Materialia 62 (2014) 197–211.

. Irina Pushkareva, Sébastien Allain, Colin Scott, Abdelkrim Redjaïmia, Antoine Moulin “Relationship between Microstructure, Mechanical Properties and Damage Mechanisms in High Martensite Fraction Dual Phase Steels” ISIJ International Vol. 55 No. 10, (2015) p. 2237-2246.

. Xiaojun Xu., Sybrand van der Zwaag, WeiXu “The effect of martensite volume fraction on the scratch and abrasion resistance of a ferrite–martensite dual phase steel”. Wear 348-349 (2016) 80–88.

. L. Schemmann, D. Raabe, F. Friedel, “Alloying effects on microstructure formation of dual phase steels” Acta Materialia 95 (2015) 386–398.S. Zaefferer

. Ersoy Erişir, Oğuz Gürkan Bilir. “A Study of Microstructure And Phase Transformation of Medium Carbon Dual Phase Steels”Metal15. - 17. 5., Brno, Czech Republic, EU (2015) pp 1417-1423.

. Majid Pouranvari, “Tensile Strength And Ductility of Ferrite-Martensitedual Phase Steels” Association of Metallurgical Engineers of Serbia MJoM Vol. 16 (3) (2010) p. 187-194.

. Z P .Xiong, A G. Kostryzhev, N E. Stanford, E V. P ereloma “Microstructures and mechanical properties of dual phase steel produced by laboratory simulated strip casting ”University of Wollongong Research Online Materials and Design, (2015) 549-537.

. Süleyman Gündüz “Bake-Hardening Response of High Martensite Dual- Phase Steel with Different Morphologies and Volume Fractions ”Acta Metall. Sin. (Engl. Lett.), 27(2), (2014) 279–289.

. Hemantha kumaryeddu “Martensitic Transformations in Steels – A 3D Phase-ﬁeld Study” PhD Thesis Stockholm, Sweden, 2012.

. Sourav Das “Bake Hardening In Low And Medium Carbon Steels ” PhD Thesis submitted to Indian Institute of Technology, Kharagpur for the award of the degree Doctor of Philosophy May, 2012.

. Sourav Das “BAKE HARDENING IN LOW AND MEDIUM CARBONSTEELS ” PhD Thesis submitted to Indian Institute of Technology, Kharagpur for the award of the degree of Doctor of Philosophy May 2012 .

. K. A. Bello, S.B. Hassan, M. Abdulwahab, U. Shehu, L. E. Umoru, A. Oyetunji, I.Y. Suleiman, “Effect of Ferrite-Martensite Microstructural Evolution on Hardness and Impact Toughness Behaviour of High Martensite Dual Phase Steel”. Australian Journal of Basic and Applied Sciences, 1(4): (2007) 407-414.

. S. K. AKAY, M. YAZICI, A. AVINC “The Effect of Heat Treatments on Physical Properties of A Low carbon steel” PROCEEDINGS oF THE ROMANIAN ACADEMY, Series A, Vol. 10, No. 1. (2009).

. M. R. AKBARPOUR F. NEMATZADEH, S. E. HASEMI AMIRI, H. REZAII “Effect of long duration intercritical heat treatment Effect of long duration intercritical heat treatmenton the mechanical properties of AISI 4340 steel ”Materials Science-Poland, Vol. 28, No. 2. (2010).

. Martin Gaško, Gejza Rosenberg (2011) “Correlation Between Hardness Andtensile Properties In Ultra-High Strengthdual Phase Steels – Short Communication” Materials Engineering - Materiálovéinžinierstvo 18 (2011) 155-159.

. L. Durrenberger, X. Lemoine, A. Molinari “Effects of pre-strain and bake-hardening on the crash properties of a top-hat section” Journal of Materials Processing Tech. P. 211, V0l. 12. (2011).

. Emil EVIN “Desing Of Dual Phase High Strength Steel Sheets For Autobody “Technical Univerzity of Košice, Kosice, Slovak Republic, EU 15. - 17. 5., Brno, Czech Republic. (2013).