بررسی رفتار سایشی فولاد گرافیتی در فرآیند کوبش فراصوتی

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی مکانیک، دانشگاه کاشان، کاشان، ایران

چکیده

مقاومت به سایش جهت افزایش طول عمر غلتک­ ها بسیار حائز اهمیت است لذا در این تحقیق برای تعیین سایش غلتک های نورد از جنس فولاد گرافیتی، از روش تست سایش و تعیین ضریب اصطکاک استفاده شد. در فناوری کوبش فراصوتی، ایجاد کار سختی و فشردگی در لایه های سطحی قطعه کار باعث بهبود برخی خواص مکانیکی از جمله صافی سطح، سختی و استحکام می شود. با شبیه سازی و ساخت ابزار ارتعاشی فراصوتی و نصب آن بر روی دستگاه تراش، عملیات کوبش فراصوتی بر روی نمونه های آماده شده از غلتک های نورد انجام گرفت. در آزمایش سایش، مقاومت به سایش در نمونه بعد از عملیات بهبود یافت. همچنین نتایج مبین کاهش ضریب اصطکاک در حدود 50 درصد بعد از عملیات می باشد. با تهیه گراف پروفیل سطح از سطح سایش مشخص شد بعد از عملیات عرض و عمق سایش کمتر می باشد. تصاویر میکروسکوپ الکترونی از سطح سایش نمونه های قبل و بعد از عملیات تهیه شد و مکانیزم سایش مورد بررسی قرار گرفت که مکانیزم چسبان و خستگی سطحی قبل از عملیات و مکانیزم خراشان بعد از عملیات مشاهده شد . با انجام فرآیند بر روی سطح غلتک های مقاومت به سایش، استحکام، صافی سطح و طول عمر آنها افزایش می یابد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of the Wear Behavior of Graphite Steel (GSH48) in Ultrasonic Peening Process

نویسندگان [English]

  • A. Abbasi
  • S. Amini
  • G. Sheikhzadeh
Department of Mechanical Engineering, University of Kashan, Kashan, Iran
چکیده [English]

Rolling mill rolls are an essential component of the rolling stand and an important factor in the efficiency and quality of rolling products. The wear durability is very significant for optimizing operation and rolls life so wear test method and coefficient friction determination were utilized in order to determine the wear of rolling mill rolls made of graphite steel (GSH48). The amount of wear was determined on samples before and after conducting ultrasonic peening technology. In ultrasonic peening technology process, making work hardening and compression on surface layers of workpiece contribute to the improvement of some mechanical properties like surface roughness, hardness, and strength. After the simulation and manufacturing of ultrasonic vibratory tool and installing it on lathe machine, ultrasonic peening technology process was performed on the specimens prepared from rolling mill rolls. In the wear test, wear durability improved in the sample after ultrasonic peening technology process. In addition, the results suggested that the coefficient friction has been reduced around 50% after the process. By preparing surface profile graph from the surface, it is perceived that the atitude and depth of wear have decreased after ultrasonic peening technology process. Scanning electron microscopy images were taken from the wear surface of the samples before and after ultrasonic peening technology process and wear mechanism was investigated that adhesive wear and surface fatigue wear mechanism before and abrasive wear mechanism after the process were observed. By performing ultrasonic peening technology process on the surface of the rolling mill rolls resistance to wear, strength, surface roughness, and their life have increased.

کلیدواژه‌ها [English]

  • Ultrasonic peening technology
  • wear
  • Graphite steel
  • coefficient friction
[1] K.Tong, M.Chakko. Prediction of roll sapling in 4-high mills based on fatigue strength of roll materials and wear pattern of roll, AISE Yearly Proceeding, (1964) 539-569.
[2] K.C.Ludema, Friction, Wear, Lubrication, Tecnology & Enginering,9(1996) 272.
[3] X.Jin, P.Wu, Z.Wen, Effects of structure elastic deformations of wheelset and track on creep forces of wheel0rail in rolling contact, Wear , (2002) 247-256.
[4] A.Azushima, Y.Nakata, T.Toriumi, prediction of effect of rolling speed on coefficient of friction in hot sheet rolling of steel using sliding trobi-simulator, Journal of Materials Processing Technology, (2009) 6.
[5] Sh.Guan qu, F.Qiang lai, G.Hong Wang, Z.Min Yuan, X.Qiang li, H.Guo,Friction and wear behavior of 30CrMnSiA steel at elevated temperatures, Journal of Materials Engineering and Performance, 25(4) (2016) 1407-1415.
[6] S.Mitrovic, D.Adamovic, F.Zivic, D.Dzunic, M.Pantic ,Friction and wear behavior of shot peened surfaces of 36CrNiMo4 and 36NiCrMo16 alloyed steels under dry and lubricated contact conditions, Applied Surface Science, (290) (2014) 223– 232.
[7] O. Unal, R. Varol, A. Erdogan, M. S. Gok,Wear behaviour of low carbon steel after severe shot peening, Materials Research Innovations,17(7) (2013) 519– 523.
[8] I. Cho, G. Song, C. Kim, A. Nobuhide, A.Combs, J. Park, C. M. Suh, J. H. Park, Y. S. Pyoun. "Nano structured surface modification of tool steel and its beneficial effects in mechanical properties, Journal of Mechanical Science and Technology, 19(11)(2005) 2151-2156.
[9] A. Cherif, Y. Pyoun, B. Scholtes, Effects of ultrasonic nanocrystal surface modification (UNSM) on residual stress state and fatigue strength of AISI 304, Journal of Materials Engineering and Performance,19(2) (2010) 282-286.
[10] W. Ting, W. Dongpo, L. Gang. ,Investigations on the nanocrystallization of 40Cr using ultrasonic surface rolling processing, Applied Surface Science, 255(5) (2008) 1824-1829.
[11] C.M.Suh, S.Y.Oh, Y.S.Pyoun, Enhascement of the punch pin durability induced by the PVD coating in production process of the automotive inner pipe, Journal of Mechanical Science and Technology, 24(5) (2010) 1061- 1066.
[12] A. Amanov, I.S. Cho, Y.S. Pyoun, C.S. Lee, I.G. Park,Micro-dimpled surface by ultrasonic nanocrystal surface modification and its tribological effects, Wear, 286 (2012) 136-144.
[13] K.Y.Zhang, Y.S.Pyoun, X.J.Cao, B.Wu, R.Murakami, Fatigue properties of SUS304 stainless steel after ultrasonic nanocrystal surface modification (UNSM), International Journal of Modern Physics, 6 (2012) 330-335.
[14] A. Abbasi, S. Amini, A. Emamikhah, Design and implementation of the ultrasonic cold forging technology process for improving surface mechanical properties of 6XB2C cold-worked alloy steel tool, Journal of Engineering Manufacture 230(2) (2014) 267-278.
[15] Y.Liu, L.Wang, D.Wang, Finite element modeling of ultrasonic surface rolling process, Journal of Materials Processing Technology 211 (2011) 2106-2113.
[16] A. Karimi, S. Amini, Steel 7225 surface ultrafine structure and improvement of its mechanical properties using surface nanocrystallization technology by ultrasonic impact, The International Journal of Advanced Manufacturing Technology 83(5)(2016) 1127–1134.
[17] C.M.Suh, G.H.Song, M.S.Suh, Y.S.Pyoun, Fatigue and mechanical characteristics of nano-structured tool by ultrasonic cold forging technology, Materials Science and Engineering A, 443 (2007) 101-106.
[18] XJ.Cao, YS.Pyoun, R.Murakami, Fatigue properties of a S45C steel subjected to ultrasonic nanocrystal surfacemodification, Applied Surface Science, 256(21)(2010) 6297–6303.
[19] N.Hansen. Hall–Petch relation and boundary strengthening, Scripta Materialia, 51 (2004) 801–806.
[20] A. Amanov, O. Penkov, Y. S. Pyun, D. E. Kim ,Effects of ultrasonic nanocrystalline surface modification on the tribological properties of AZ91D magnesium alloy, Tribology International, 54(2012) 106–113.
[21] A. Abbasi, S. Amini, G.A. Shikhzade ,Investigation of ultrasonic peening technology on the GSH48 graphite steel, Modares Mechanical Engineering 16( 9) (2016) 29-36.
[22] Y.Estrin, A.Vinogradov, Fatigue behavior of light alloys with ultrafine grain structure produced by severe plastic deformation, International Journal of Fatigue, 32 (2010) 898-907.
[23] M.Multigner, S.Ferreira, E.Frutos, M.Jaafar, J.Ibanez, P.Marin, Superficial severe plastic deformation of 316 LVM stainless steel through grit blasting: Effects on its microstructure and subsurface mechanical properties, Surface & Coatings Technology, 205 (2010) 1830-1837.
[24] Y.Sun, Sliding wear behavior of surface mechanical attrition treated AISI 304 stainless steel, Tribology International 57 (2013) 67-75.
[25] F.Balaha, B.Langenecker, Plastic deformation under simultaneous cyclic and unidirectional loading at low and ultrasonic frequencies, Materials Science and Engineering, 68 (1984) 197-206.