Comparison of Microstructure and Mechanical Properties of Mo40 Steel in Ferrite-Martensite dual phase and quenched tempered condition

Document Type : Research Paper

Authors

• mohsen kashefi ¹
• seyyed sadegh GHASEMI BANADKOUKI ²

¹ MATERIAL AND METALORGY DEPARTMENT OF YAZD UNIVERSITY

² MATERIAL ENGINNIERING- NINING AND METALURGICAL DEPARTMENT- YAZD UNIVERSITY- YAZD

Abstract

In this research, has been compared fatigue behavior of Mo 40 steel in ferrite-martensite dual phase condition and quenched-tempered microstructure. The ferrite-martensite dual phase samples were prepared from intercritical annealing heat treatment process for 40 minute at ( α + γ ) dual phase region. The quenched martensite samples after heating at 860 ° C and quenched in water, were tempering heat treatment at 600 ° C for 3 0 minute. The Hardness, tensile and fatigue tests have been supplemented with optical and electron microscopies. The result shown that hardness of ferrite-martensite dual phase is more than quenched tempered sample. Also , tensile strength of ferrite martensite dual phase samples is lower than quenched-tempered sample, while the fatigue strength of samples is more than quenched-tempered sample. These results are rationalized to strengthening un tempered martensite phase in ferrite martensite dual phase sample compared to tempered martensite in quenched tempered sample.

Keywords

• Mo40 steel
• ferrite
• martensite
• work hardening
• fatigue strength

20.1001.1.22285946.1397.9.33.7.1

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References

References:
1-Speich, G, R., ''Fundamentals of dual phase steels'', New York: AIME, (1981).
2-Rashid, M, S., ''Formable HSLA and dual-phase steels'', in proceedings of the metallurgical society of AIME, Michigan. M.S., USA, (1979).
3-Waterschoot, T, Vandeputte S, D., De, A and Cooman, B, ''Static strain aging phenomena in cold-rolled dual-phase steels'', Metallurgical and Materials Transactions, Vol.34, pp.781–791, (2003).
4-Garcia, C., hua, K., and deardo, A., ''Metallurgy and continuous galvanizing line processing of high-strength dual-phase steel micro alloyed with niobium and vanadium'', 8th international conference on zinc and zinc alloy coated steel sheet (galvatech 2011) genova, Italy, (2011).
5-Ghaheri, A., Shafyei, A and honarmand, M., ''Effects of inter-critical temperatures on martensite morphology, volume fraction and mechanical properties of dual-phase
steels obtained from direct and continuous annealing cycles'', Materials and design, Vol. 62, pp.305–319, (2014).
6-Tayanc, M., Aytac, A and Bayram, A., ''The effect of carbon content on fatigue strength of dual-phase steels'', materials and design, Vol. 28, pp1827–1835, (2007).
7-Okayasu. M., Sato, k., Mizuno, M., Hwang, D.Y and Shin, D.H., ''Fatigue properties of ultra-fine grained dual phase ferrite/martensite low carbon steel'', International journal of fatigue, Vol. 30 pp.1358–1365, (2008).
8-Molaeia, M, J., Ekrami, A., ''the effect of dynamic strain aging on fatigue properties of dual phase steels with different martensite morphology'', materials science and engineering Vol. 527, pp.235–238, (2009).
9-Shengci, l., yonglin, k and shuang k., ''Effects of microstructure on fatigue crack growth behavior in cold-rolled dual phase
87 مجله مواد نوین/ جلد 9/شماره 1/ پاییز 1397
steels'', Materials science & engineering, Vol. 612, pp. 153–161, (2014).
10-Roslinda, I., Yunan, P., ''influence of ferrite fraction within martensite matrix on fatigue crack propagation: an experimental verification with dual phase steel''. Materials science and engineering, Vol. 552, pp547– 554, (2012).
11- Cheng Ji, Lei Wang, Miao-Yong Zhu, "Effect of Subcritical Annealing Temperature on Microstructure and Mechanical Properties of Scm435 Steel", Journal of Iron and Steel Research, International. 2015, 22(11): 1031-1036.
12-Fereiduni E., ghasemi banadkouki S, S., ''Improvement of mechanical properties in a dual-phase ferrite–martensite AISI 4140 steel under tough-strong ferrite formation'', Materials and design, Vol. 56, pp. 232–240, (2014).
13-Krauss, G., ''principles of heat treatment of steel”, ASM, metal park, pp.240-245, (1980).
14 -دکتر محمد علی گلعذار، اصول و کاربرد عملیات
حرارتی فولادها، مرکز نشر دانشگاه صنعت اصفهان، چاپ
هشتم، ویرایش دوم.
15 -دکتر شهرام خیراندیش،دکتر محسن اسدی اسدآباد.
"فولاد های دوفازی". انتشارات دانشگاه علم وصنعت ایران،
چاپ اول، 1392 .
16-Wan, C, M., Chou, K, C., Jahn, M, T and Kuo S. M., ''Fatigue studies on dual-phase low carbon steel'', Journal of materials science. Vol 16, pp. 2521-2526, (1981).