ISSN 2395-1621 Exprimnal and Compur Aidd Sudy of Anisoropic Bhavior of Marial o Rduc h Mal Forming Dfcs #1 Tausif N. Momin, #2 Vishal B.Bhagwa 1 ausifnmomin@gmail.com 2 bhagwavb@gmail.com #12 Mchanical Enginring Dparmn, Pun Univrsiy ABSTRACT This rsarch work givs informaion abou h bhaviour of cold rolld sl IS 513_2008 CR2_D for rducing h mal forming dfcs. CR indicas Cold Rolld and D dnos Drawing grad. Wrinkls, dn, springback, hinning, insufficin srching c. ar h problms idnifid whil prforming sh mal forming opraions. For cold rolld sl marial, ou of various dfcs h damag du o wrinkl formaion was sudid in his papr. In his papr, rsarch is don for sudying h bhavior of cold rolld sl marial usd in dp drawing procss. In his rsarch work, wrinkling dfc is sudid xprimnally and wih h hlp of FE sofwar. Kywords Dp drawing, Fricion, FE sofwar, Wrinkling. ARTICLE INFO Aricl Hisory Rcivd :18 h Novmbr 2015 Rcivd in rvisd form : 19 h Novmbr 2015 Accpd : 21 s Novmbr, 2015 Publishd onlin : 22 nd Novmbr 2015 I. INTRODUCTION Sh mal forming procsss ar on of h manufacuring procsss which consis of svral procsss such as plasic dformaion procsss and cuing procsss. In dp drawing which fails undr h cagory of plasic dformaion procss, du o h providd by punch, h mal blank is shapd ino h di caviy. Various yps of dfcs lik insufficin srching, hinning, rupur c. occurs in many manufacuring procss and ohr dfcs such as wrinkling, aring, cracks, hinning occurs paricularly whil carrying ou dp drawing opraions. Dp drawing procss occurs lik h raw marial i.. blank is shapd ino h caviy of h di. For prforming any dp draw opraion mainly manual, hydraulic, pnumaic and mchanical prsss ar usd. A sris of work on wrinkl supprssion hav conducd by Yoshida al. [1]. Hydraulic prss of capaciy 250 on was usd for h wrinkling analysis purpos. L al. hav sudid h rason of wrinkls a h cornr ara [2]. In his rsarch work h analysis of wrinkl of on of h auo componn is don. Whil prforming mal forming procsss h dfcs lik wrinkls, cracks wr found svral ims in h componn formd. Afr doing liraur survy i can b undrsand ha wrinkls and cracks can b minimizd o larg xn. prssur, nos radius, gomry, draw dph, anisoropic propris of marial, di dsign and shap of work pic, conac condiions c. ar h various paramrs which mainly rsponsibl for wrinkl formaion. By considring all h facors i is difficul o analyz wrinkling iniiaion and growh. Th main rason bhind his is h ffc of h ach facor is vry complx and for small dviaions in facors wrinkling bhavior sudy may b a wid scaring of daa. In his rsarch work, mainly in dp drawing procss of h cylindrical cup, h phnomnon of wrinkling iniiaion and crack growh was sudid. Th work was carrid ou by prforming xprimnaion on 2015, IERJ All Righs Rsrvd Pag 1
singl sag hydraulic machin and h rsuls wr confirmd wih Auoform sofwar. Th srngh found o b vry wak whil doing h assmbly of h pars wih h hlp of wlding or any ohr joining opraion du o h formaion of wrinkls and wrinkls ar also rsponsibl for dsroying h apparanc of h componn. Bcaus of h abov rasons wrinkling is no dsirabl. Bcaus of h xcssiv comprssiv acing on h sh mal, wrinkl formaion occurs. In cas of mulisag opraions, high frquncy wrinkls can damag h di. II. CHEMICAL COMPOSITION of MATERIAL Th chmical composiion of cold rolld sl sd on opical mission spcromr. TABLE I CHEMICAL COMPOSITION of MATERIAL Si C P Mn Bi Ni 0.0083 0.0425 0.004 0.2292 0.002 0.0138 Sn B As Zn S C 0.0025 0.0004 0.002 0.002 0.002 0.003 Cr Al Co Cu La Pb 0.158 0.0465 0.0062 0.0052 0.001 0.003 Ca Ti F Zr Nb Mo 0.0002 0.001 99.6 0.002 0.003 0.002 W V % % 0.001 0.001 III. ANISOTROPIC PROPERTIES of COLD ROLLED STEEL Anisoropic propris ar h dircional dpndn propris mans if rolling dircion is changd hr will b sligh variaion in mchanical propris. I can b calculad by uni-axial nsion ss conducd in 0, 45 and 90 wih rspc o rolling dircion. Plasic Srain Raio (R 0 ) = Fig 2. Spcimn wih diffrn rolling dircion Lankford cofficin (R) = Normal R valu of h marial srongly dpnds on h srain. Calculaion of planar anisoropy cofficin valu R p R p = For Isoropic marial Th marial has sam propry in all dircions. For Planar anisoropy Th R valus vary a diffrn dircions o h rolling dircion: R 0 no qual o R 45 no qual o R 90. This can lad o 'aring' in dp drawing. For Normal anisoropy R 0 = R 45 = R 90 bu no qual o 1. Th valu R drmins h limiing drawing raio, and R p is in corrlaion wih h xn of arring. A combinaion of high R and low R p provids opimal drawabiliy. Th rsuls obaind afr doing uni-axial nsil sing is abulad as follows: TABLE II MATERIAL PROPERTIES of COLD ROLLED STEEL Paramrs Valus Yilding srss, σs (MPa) 217.78 Ulima nsil srss, σ u 307.83 (MPa) Toal longaion, δl (%) 40 Srain hardning xponn, n 0.2136 Hardning cofficin, k (MPa) 502.73 R 0 1.914 R 45 1.1615 R 90 1.77 R avg. 1.50175 Lankford Cofficin Fig1 Srss srain cur in diffrn rolling dircion In abov fig.1, h naur of srss srain curv in diffrn rolling dircion is shown. Th srss srain curv bhavior is almos sam in diffrn rolling dircion. Calculaion of normal R valu is akn o b avrag r valu: 2015, IERJ All Righs Rsrvd Pag 2
IV. EXPERIMENTATION A. A. Exprimnal Sup As shown if figur 3 hydraulic prss of capaciy 250 Tons was usd for final componn. Dp drawing is a procss in which final componn is in cup shap and producd from Sh mal. In his cas singl sag draw is don and finally invrd cup was obaind. J. Cao al. hav sudid h concp of flang wrinkling [3]. Fig 3 and di sup Fig 4. Effc of varying prssur & Draw dph Fig 5. Locaion of cup in auomobils For prvnion of wrinkling, blank-holdr was usd bcaus i can apply sufficin prssur on h blank sudid in [4]. Thrfor, largr radial nsion is crad on h flang and highr nsil srss is ndd on h cup wall, whil drawing cups a largr draw raios. By varying h paramrs lik blank prssur and draw dph, h componn which is obaind is shown in fig. 4. Liao al. hav sudid h wrinkling of samping of a moor cycl oil ank. In auomobil, h acual locaion of cup is shown in figur 5. B. Obsrvaion Tabl By varying h paramrs lik draw dph and blank prssur, h obsrvaions wr akn. From abl 3, i can b sn ha h opimum valus wr obaind a draw dph 29 mm and blank prssur 60 kg/cm 2. TABLE III EFFECT of VARYING BLANK HOLDING PRESSURE and DRAW DEPTH S r. Holdin Major Wrink Dra -w Conclu s-ion N o. (Kg/c m 2 ) g Prssur (Kg/c m 2 ) -l Wav s (mm/s) dp -h (m m) 1 100 30 17 8.6 26 Larg 2 100 35 15 8.6 26 Dcras -d 3 100 40 12 8.6 26 Dcras -d 4 100 45 4 8.6 26 Dcras -d 5 100 60 Absn 8.6 26 Ngligi b-l wavin ss 6 100 65 Crack 9.3 24 Thinnin -g & Crack 7 100 60 Absn 8 100 60 Absn 7.5 30 Wavin ss visibl 7.9 29 No wrinkl s c. Effc of Various Fricion Marial As shown in Tabl 4, 5 and 6, for lubricaion purpos hr wr diffrn fricion marial usd as a lubrican. By using Plasic papr and palm oil, h mos ffciv rsul was obaind. In forming procss whn palm oil usd as a lubrican for cup formaion, hr was on drawback found ha is claning of cup is ncssary afr forming.
V. SIMULATION A. A. Craion of Modl By using CATIA, h numrical modl of forming of dp drawing procss was buil up. By using CATIA V5 R17, h sampl modl crad which is shown in fig.7 and by using Auoform sofwar i was analyzd furhr. Fig 6. Us of plasic papr as a lubrican TABLE IV EFFECT of PLASTIC PAPER 100MICRON- 0.1MM as a FRICTION MATERIAL No. Draw dph Conclusion prsssur 1 100 50 7.7 29 Lss 2 100 55 7.7 29 Dcrasd 3 100 60 7.7 29 No wrinkls 4 100 65 9.7 23 Wrinkls TABLE V EFFECT of PALM OIL as a FRICTION MATERIAL No. Srok Conclusion prsssur 1 100 50 9.7 23 Wrinkls 2 100 55 7.7 29 Lss 3 100 60 7.7 29 No wrinkls 4 100 65 7.7 29 Thinning Fig 7. Componn 3 d modl crad in CATIA V5 R17 B. Analysis of Modl By using Auoform sofwar, h numrical modl was analyzd. For approaching owards h opimum valu, all h valus wr analyzd. I was ha a blank prssur 60kg/cm 2 and h draw dph 30mm saf rgion was dcrasd and for sam blank prssur and 29mm draw dph, incrasd safr rgion was. TABLE VI EFFECT of HYDRAULIC OIL GRADE 68 as a FRICTION MATERIAL N Srok Conclusion o. prsssur 1 100 50 9.7 23 Wrinkls 2 100 55 9.7 23 Wrinkls 3 100 60 8.6 26 Minu wavinss 4 100 60 7.5 30 Wavinss visibl 2015, IERJ All Righs Rsrvd Pag 4
was and also mor comprssion rgion was formd which is highly undsirabl. 2) From abl 3, i can b sn ha if blank prssur is incrasd hn wrinkl formaion was dcrasd. 3) A blank prssur 60 kg/cm 2 and draws dph 29mm, h opimum valu was as shown in Tabl 3, 4 and figur 8 and figur 9 shows opimum valus. 4) By using Plasic papr and palm oil as a lubrican, h mos ffciv rsul was obaind. 5) Exprimnal and simulaion rsuls wr found o b narly sam. REFERENCES Fig. 8 Componn formabiliy and FLD curv for prssur 60kg/cm 2 and draw dph 29mm [1] K. Yoshida, H. Hayashi, K. Miyauchi, Y. Yamamoo, k. Ab, M. Usuda, R. Ishida, Y. Oik, Th ffc of mchanical propris of sh mals on h growh and rmoving of buckls du o non uniform srching, Sci. Pap. Ins. Phys. Chm. Rs. 68 (1974) 85-93. [2] J.H. L, B. S. Chun, Invsigaion on h variaion of dp drawabiliy of STS304 using FEM simulaions. [3] X. Wang, J. Cao, An analyical prdicion of flang wrinkling in sh mal forming, J. Manuf. Procsss 2 (2) (2000) 100 107. [4] T. Yagami, K. Manab, Y. Yamauchi, Effc of alrnaing blank holdr moion of drawing and wrinkl liminaion on dp drawabiliy. Journals of marials procssing Tch. 187-188(2007) 187-191. [5] Fuh-Kuo Chn, and Yu-Ching Liao, Analysis of drawwall wrinkling in h samping of a moor cycl oil ank. Journals of marials procssing Tch. 192-193 (2007) 200-203. Fig. 9 Componn formabiliy and FLD curv for prssur 60kg/cm 2 and draw dph 30 mm VI. CONCLUSION 1) If h draw dph is incrasd, hn dcrasd 2015, IERJ All Righs Rsrvd Pag 5