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渐减的凹模拉可使有裂缝的自由薄钢板起皱R. Narayanasamy a,*, C. Sathiya Narayanan ba Department of Production Engineering, National Institute of Technology, Tiruchirappalli 620 015, Tamilnadu, Indiab Department of Production Engineering, J.J. College of Engineering and Technology, Tiruchirappalli 620 009, Tamilnadu, India Received 4 January 2005; accepted 8 July 2005 Available online 2 September 2005摘要：起皱是通常以在深的拖拉操作期间的薄金属板的形式观察的一种失败的方式。关于通过圆锥形和等切面曲线的凹模使有裂缝的自由钢板起皱的一项实验研究 将在这篇文章讨论。有裂缝的自由钢板的机械特性和可纺性参数被确定并且他们与起皱的行为相关。这些薄钢板的限制拉比率(LDR)与薄钢板的厚度有关， 打孔机直径和薄钢板厚度的比率， 正常的各向异性和非空间的参数(包括打孔机直径，薄钢板厚度，正常的各向异性和应变硬化指数)。上述起皱行为的研究被进行在名义上润滑的和非润滑的两不同状况下，并将他们进行比较。在此研究中，很清楚地知道LDR可能与上述参数有关。-2005 Elsevier Ltd. 版权所有关键字：有裂缝的自由钢板；起皱；圆锥形的凹模模子；等切面曲线的凹模模子1. 介绍经常能在金属板成型过程中观察到皱纹。皱纹的存在不能被最后的产品所接受。在近几年，为了降低在操作期间形成的产品的重量和皱纹，使用了有高力量的更薄的线规薄板。研究人员目的是在薄金属板形成期间避免这样的皱纹。希尔1的bifurication 标准能用来预知皱纹的形成。起皱的凸缘的进攻被Needleman2通过使用的迅速的杯子测试进行了分析。几个理论和实验作品已经被关于在不同的条件下的不同的材料的起皱的行为进行了研究。金和其儿子 3对各向异性的薄片的起皱限制图解(WLD) 进行了数值分析的评价。Joao Pedro de Magalhaes Correia 和Gerard Ferron 4调查了塑料的各向异性对起皱进攻的影响。Narayanasamy和Sowerby 5检查了304 等级的、双阶段钢和断开拖曳的铝的高品质的不锈钢的起皱行为。在这个工作中，对有裂缝间的自由的厚度为0.6毫米的、涂上和没有涂上0.85毫米的、0.9, 1.2 和1.6 毫米的钢使用一双重行动能力2000 kN的水压机的使用圆锥形凹模模子和等切面曲线的凹模模子的起皱行为进行了研究。最近发展的有裂缝的自由钢板有非常少数额的碳和氮。但是，铝合金用于汽车应用是由于他们的质量轻，而且可以节省燃料，车辆安全的需求使用户更喜欢用这一材料增加汽车本身的质量和车辆的绝对重量 6,7 。最近发现的有裂缝的自由钢板有一些极好的特性。他们适于galvanneal 薄层，此薄层需要汽车身体工作时在别处给予。有裂缝的自由钢板在晶界没有碳化物沉淀8。 因此，他们有极好的可使用性和机械特性(由于象锰和硅那样的成合金元素的存在)。有裂缝的自由钢板是钛、铌趋于稳定，而且他们有好的可纺性9。在近几年， 很多工作已经被进行发展有裂缝的自由钢板， 通过理解微结构方面来提高特性，这就象在别处解释的那样控制有裂缝的自由钢板的变形行为 10,11 。在目前的工作里，在使用圆锥型和等切面曲线的凹模模子的试验工作的帮助下，研究了在润滑和非润滑情况下有裂缝的自由钢板的起皱的行为和他们在拖曳过程中的适宜性。 术语LDR限制拉比率实际压力实际张力力系数环张力径向应变应变硬化指数常态各向异性打孔机直径初始薄片厚度有裂缝的自由钢板塑性应变增量比率2. 试验工作使用上述上述薄片，单轴的抗拉的试验通过准备样品在, 以及 对来自使用Hounsfield tensometer的每个薄片的滚动方向的定向被处理。从这些测试中可获得外延数据的负载。重要的参数即应变硬化指数(n),塑性应变比率(R)，以及力系数(K)沿着上述的3个方向被象解释在5里的那样从抗拉的试验中查明 。正常的各向异性（）和刨床各向异性()由沿着上述的3 个方向使用在下面给的用来确定R值计算：在实验中使用的圆锥形和等切面曲线凹模模子分别如图1和2所示。使用这些凹模模子时，探究了不同润滑条件。图1.拉模冲模图2.等切面曲线凹模模子为了确定限制的直径，对给定的薄片厚度，圆的空白的直径在连续的试验过程中被逐渐增加直到皱纹出现。在拖曳操作期间，一根栅栏环绕图案被在空白上打印来测量径向应变()以及环张力()。3. 结果和讨论这里研究的钢板的正常的各向异性和应变硬化指数值在表一给出。当薄片在拉模上被拖曳时的限制拉比率和限制直径在表格二给出。当薄片在等切面曲线模上被拖曳时的限制拉比率和限制直径在表格三给出。表一：正规各向异性和应变硬化指数值金属片初始厚度（mm）平均应变硬化指数值平均各向异性值无涂层有裂缝的自由钢板0850344318770有涂层有裂缝的自由钢板0850291919726有裂缝的自由钢板060282813208有裂缝的自由钢板090300811488有裂缝的自由钢板120267109704有裂缝的自由钢板160331512347表二：使用拉模的限制拉伸比率值材料情况初始厚度（mm）限制直径（mm）LDR无涂层有裂缝的自由钢板0.851052.100有涂层有裂缝的自由钢板0.851002.000无润滑有裂缝的自由钢板0.6801.600有润滑有裂缝的自由钢板0.9851.700无润滑有裂缝的自由钢板1.21002.000有润滑有裂缝的自由钢板1.2851.700有润滑有裂缝的自由钢板1.61252.500表三:使用等切面曲线拉模的限制拉比率值材料情况初始厚度（mm）限制直径（mm）LDR有裂缝的自由钢板0.6801.600有裂缝的自由钢板0.9901.800有涂层有裂缝的自由钢板0.85951.900无涂层有裂缝的自由钢板0.851052.100有裂缝的自由钢板1.21102.200有裂缝的自由钢板1.61302.600在拉动拉模时,带有薄片厚度的有裂缝的自由钢板的限制拉比率的的变化如图三所示。 在拉动等切面曲线的模子时,带有薄片厚度的有裂缝的自由钢板的限制拉比率的的变化如图四所示。以上两种情况下，限制拉比率随着薄片厚度的增加而增加。图五显示了薄片在拉模中拉动时限制拉比率随着的变化情况。图六显示了薄片在等切面曲线模子中拉动时限制拉比率随着的变化情况。这两种情况下，限制拉比率都随着的增加而减小。图七显示了在拉模中限制拉比率随着正规各向异性的变化情况。图八显示了在等切面曲线模子中限制拉比率随着正规各向异性的变化情况。当拉动拉模时，限制拉比率随着正规各向异性值的增加而增加。图九显示了限制拉比率随着包括拉模的钻床直径、初始厚度、正规各向异性和应变硬化指数的非维参数变化情况。图十显示了限制拉比率随着包括等切面曲线模子的钻床直径、初始厚度、正规各向异性和应变硬化指数的非维参数变化情况。限制拉比率随着以上非维参数值的增加而减小。不过，上述结果显示：当在等切面曲线模子中拉动时，有裂缝的自由钢板的限制拉比率更大。图十一显示了拉动拉模时有裂缝的自由钢板的塑性应变增加比率的变化，拉动等切面曲线模子时有裂缝的自由钢板的塑性应变增加比率的变化情况在图十二。塑性应变增加比率在拉模的情况下线性增加，而在等切面曲线模子的情况中变化不不清楚。图十三显示了有预加应变的有裂缝的自由钢板薄片的塑性应变增加比率的变化情况。这也显示了塑性应变增加比率随着值的增加而增加的本性。 图三：在拉模中限制拉比率随薄片厚度的变化 图四：在等切面曲线模子中限制拉比率随薄片厚度的变化图五：在拉模中限制拉比率随的变化 图六：在等切面曲线模子中限制拉比率随的变化图七：在拉模中限制拉比率随正规各向异性值的变化 图八：在等切面曲线模子中限制拉比率随正规各向异性值的变化 图九：在拉模中限制拉比率随着包括拉模的钻床直径、初始厚度、正规各向异性和应变硬化指数的非维参数的变化图十：在等切面曲线模子中限制拉比率随着包括拉模的钻床直径、初始厚度、正规各向异性和应变硬化指数的非维参数的变化图十一：在拉模中塑性应变增加比率随的变化 图十二：在等切面曲线模子中塑性应变增加比率随的变化图十三：预加应变情况下，在等切面曲线模子中塑性应变增加比率随的变化4. 结论据上述结果，得出下列结论。限制拉比率随着厚度增加而增加，也随着塑性应变增加值增加而增加。限制拉比率随着 和包括钻床直径、初始厚度，正规各向异性值和应变硬化指数的非维参数值的增加而减少。此性质是在两重模子里共有的。比较拉模和等切面曲线模子，限制拉比率在等切面曲线模子中拉动时更大一些。参考文献:1 Hill R. A general theory of uniqueness and stability in elastic/plastic solids. J Mech Phys Solids 1958;6:23649.2 Triantafyllidis N, Needleman A. An analysis of wrinkling in the Swift cup test. J Eng Mater Technol 1980;102:2418.3 Kim Y, Son Y. Study on wrinkling limit diagram of anisotropic sheet metals. J Mater Process Tech 2000;97:8894.4 de Magalhaes Correia JP, Ferron G. Wrinkling predictions in the deep drawing process of anisotropic metal sheets. J Mater Process Technol 2002;128:17890.5 Narayanasamy R, Sowerby R. Forming behaviour of some sheet steel materials when drawn through a conical die. J Mater Process Technol 1993;39:4353.6 Uenishi A, Teodosiu C. Constitutive modelling of the high strain rate behaviour of interstitial free steel. Int J Plasticity 2004;20:91536.7 Uenishi A, Teodosiu C. Solid solution softening at high strain rates in Si and/or Mn added interstitial free Steels. Acta Mater 2003;51:443746.8 Feliu Jr. S, Perez-Revenga, ML. Effect of alloying elements (Ti,Nb, Mn and P) and the water vapour content in the annealing atmosphere on the surface composition of interstitial free steels at the galvanising temperature, Appl Surf Sci; 2004 in press.9 Oudin A, Barnett MR, Hodgson PD. Grain size effect on the warm deformation behaviour of a Ti-IF steel. Mater Sci Eng A 2004;367:28294.10 Li BL, Godfrey A, Meng QC, Liu Q, Hansen N. Microstructural evaluation of IF steels during cold rolling. Acta Metall 2004;52:106981.11 Li BL, Godfrey A, Liu Q. Subdivision of original grains during coldrolling of Interstitial Free steel. Scripta Metall 2004;50:87983.F82H钢小号样本的机械特性, , a Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki-ken 319-1195, Japanb National College of Technology, Hachinohe, Aomori-ken 039-1192, Japanc Hokkaido University, Kita-ku, Sapporo 060-8628, JapanReceived 1 February 2005; received in revised form 12 August 2005; accepted 12 August 2005Available online 24 January 2006摘要：小样品测试技术(SSTT)已经发展且用来调查核材料的机械特性。SSTT在测试反应堆和基于加速器中子中被有效照射量的限制供应控制且充满粒子源头。在这项研究中，新弯曲测试机器得到发展并获得F82H钢的预断裂的t / 2-1/3CVN(Charpy V型槽口)的20毫米长的小弯曲样品的破裂行为，且9毫米长的变形破裂袖珍的弯曲样品(DFMB)和0.18DCT 类型的磁盘和断裂行为在进行检查。F82H钢的试样尺寸对DBTT的影响通过使用t / 2CVN，1/3CVN和t / 2-1/3CVN被检查，并且t / 2-1/3CVN 和1/3CVN的DBTT比t/2-CVN的DBTT要小。在F82H 标准方面的由于氦和位移损害的DBTT行为在大约、 50或100MeV氦离子在0.03 dpa也被小钻床测量进行测试。 2005 Elsevier B.V. 。版权所有。关键字：断裂韧度；辐射效应；低的活化材料；柔软-脆弱过渡；实验技术1. 介绍小样品测试技术(SSTT)已经被发展并研究核材料的机械特性。在测试反应堆和基于加速的中子和电荷离子源15，小样品测试技术被有效辐射量的限制供应推动。在小样品断裂测试技术中，最近努力寻求Odette et al.提出的主要的弯曲变形方法结构的Bcc合金，如现在被首选为熔接反应堆的以铁酸盐为主要成分/马氏永磁体6,7。主要的弯曲变形描述了在测量零部件分裂开始坚韧的完整评价时的一显著扩展和新近发展的修改。在利用小样品获得有意义和有用的断裂韧度信息上的成功导致了一种在更大程度上降低断裂的大小。多种实验已经被设计来分析现有的小量样品的机械性能的数据，如张力的、低的和高的周疲劳、断裂韧度、疲劳的裂缝发展、加压管、锯齿状和预断裂冲击样品以及3毫米直径磁盘。这些样品和技术暂时作为在国际熔化材料熔接设备(IFMIF)的材料反应证实的候选的材料，IFMIF是一基于D-Li的概念设计的高能中子源8。在这研究里，我们检查使用三种0.18DCT（磁压力）样品的、预断裂t/2-1/3CVN(Charpy V槽口) 的F82H钢的断裂韧度，将其表示为t/2-1/3PCCVN，它有20mm长、9mm长的变形且断裂袖珍弯曲样品。0.18DCT 和1/3CVN 样品最近用于在降低活化作用的以铁酸盐为主要成分(RAF)的钢的中子辐照研究的标准断裂样品。但是，0.18DCT 和1/3CVN 样品的体积在象IFMIF那样的照射设备的空间内不比此情况下小。降低样品体积对照射性能来说是很重要的。熔接反应堆的覆盖结构由不同厚度的RAF钢板和钢管组成，而且我们应该检查试样尺寸在断裂韧度的特性上的依赖性。t / 2 CVN 样品降低了1/3CVN样品宽度的一半，而且DFMB样品降低了1/3CVN的宽度和长度的一半。一个新的弯曲测试机器已经生产并获得t / 2-1/3PCCVN和DFMB的小弯曲样品的断裂行为。不同形状的不同的类型的F82H钢的断裂行为已经被检查。在这项研究过程中使用的这类型样品是0.18DCT，1/3CVN，t / 2-1/3CVN，t / 2-1/3PCCVN，DFMB和小钻床(SP)样品。这项研究的目的是： (1) 生产为DFMB和t / 2-1/3PCCVN的小样品测试机器的断裂韧度并且在RT中检查标准F82H钢的断裂行为；( 2 ) 检查标准F82H钢的试样尺寸对柔软-脆弱转变温度(DBTT)的影响。 2. DFMB、t/2-1/3PCCVN和0.18DCT样品的制作0.18DCT、t / 2-1/3PCCVN和DFMB样品的疲劳预断裂通过使用一台Shimazu Lab-5u的疲劳试验机器被引起。0.18DCT 样品(直径为12.5毫米，厚度为4.63毫米) 在TL方向内机械加工而成，因此裂纹扩展与滚方向平行。疲劳预断裂在室温下，裂缝长度与样品宽度的比率(a/W)大约为0.46。随后是对样品厚度的10%的每边上的孔型设计。0.18DCT 样品的疲劳预断裂范围长度大约为1.31.4 mm。第一步的外加负载在40Hz下在108与1079N之间变化，而在下一步中在88和883N之间变化。在t / 2-1/3PCCVN和DFMB样品里，预断裂分别由带有V槽口和U槽口的盘子形状引起，盘子的大小是20mm20mm的正方形，厚度为3.3毫米。在t / 2-1/3PCCVN里，V槽口的深度和角度分别是0.51毫米和。在DFMB样品里，U槽口采用通过使用一个0.15毫米的剪钳来降低槽口，且U槽口的深度和宽度是大约分别是0.5毫米和0.2毫米。为t / 2-1/3PCCVN和DFMB样品准备的盘子负载在40赫兹下，在294和2942N之间变化。在预断裂的程序之后，这个盘子被金属丝切成大约1.7毫米厚的薄片。t / 2-1/3PCCVN和DFMB样品预断裂的长度大约分别是0.9毫米和0.3毫米。裂缝长度和样品厚度的比率，a/W，对DFMB和t / 2-1/3PCCVN样品来说，比值控制在0.40到0.45。在这项研究过程中的样品的化学组成在表1给出。 3.断裂韧度测试3.1.DFMB和t/2-1/3PCCVN的断裂韧度测试图1显示了新的弯曲测试机器,它是人造的用来获得20mm 长的t/2-1/3PCCVN (W: 3.3 mm,H: 1.65 mm)和9mm长的DFMB(W: 1.65 mm, H: 1.65 mm)的非常小弯曲样品的断裂行为的。温度可以被高压和电暖器的液体氮的蒸汽的数量控制，并且它可以从-196变到300 。温度的变化在大约0.5之内。图2(a和b)分别显示了设置在弯曲测试机器的活动场所上的DFMB和t/2-1/3PCCVN样品。0.5毫米距离的刻度被确定在样品背面的装置上。在样品活动场所的样品位置的调节由一个小的千分尺控制，且被固定在机器上。测压元件位置可以通过使用一个线性计量器(Mitutoyo，LGF sereies)来测量，而且它被位置的反馈控制系统控制着。线性计量器位置的精确度是0.5。在带刻度的样品台上的样品位置可以用一个小的工具来调整。十字架形状的头逐渐下降到V槽口样品的中心。样品的位移在如图1（b）中所示的确定在室里的视口中用一个光探针(Keyence，LS-7030T)正确地测量，样品位移的精度为0.15。图3(a和b)分别是在20 下，DFMB和t/2-1/3PCCVN的F82H样品的负载位移曲线。0.1毫米/分的十字架型头是在卸载依从方法下选择的。紧凑和3点弯曲样品的断裂韧度测试在ASTM E 81389和E 182099a的指导下执行。在RT下，DFMB和t / 2PCCVN的断裂韧度大约分别为170和230MPa。这些值比第3.2 部分描述的0.18DCT样品的值小。 Fig. 3. Load and displacement curves obtained from: (a) DFMB and(b) pre-cracked t/2-1/3CVN specimens of F82H-std (low N).3.2. 0.18DCT的断裂韧度测试图4显示了DCT测试机器，它是人造的用来获得0.18DCT样品的断裂行为的。图4(c)显示了放在侧面的F82H标准钢的圆盘压坯试样的计量器。断裂韧度测试可以在温度范围为从-180到300进行，和温度被LN2蒸汽或电暖器系统控制。张力、夹子标准尺位移、十字架型头的位移和温度在测试中测量并且记录。对夹子标准尺位移曲线的负载如图5所示。在卸载依从方法下，十字架型头的位移速度为0.2 mm/min。F82H标准(低的N)的断裂韧度在RT下大约是330MPa。这个值与以前的研究9非常相似4. 小的穿孔器测试小型钻床(SP)测试机器是在一个JMTR热实验室的热室内生产的10。SP测试机器由一个负荷控制器、能装12个样品的转车台、一个真空室和一个炉膛组成。样品座由上面和下面的固定器、一台钻床和一个1毫米直径的钢球组成。钢球和钻床用钻床杆挤着。SP机器的最大负荷和钻床杆的直径分别为5 kN 和8毫米。钻床的速度为0.5毫米/分。SP能量从负载绕度曲线到断裂载荷算起。在这项研究中，厚度为0.3mm 磁盘的F82H样品被在日本原子能研究所的为先进辐射应用的Takasaki离子加速器(TIARA)设备上的AVF回旋加速器在120下的100MeV粒子束从0.6mm的F82H金属薄片照射。位移损耗大约是0.03 dpa，氦的停止范围大约是1.25毫米的。在着个样品中，所有的氦原子都穿过被照射样品。在照射之后，SP试验在日本材料测试反应堆(JMTR)的原子核实验室进行。SP能量被作为温度的函数计算，如图6所示。在这项研究里，由于位移严重损害的DBTT的变化 在此实验中发生，且为23。在以前的50MeV照射实验的研究里11， 替代损害在F82H钢的位移损害也大约0.03dpa和氦离子的计划范围在能量减少的情况下为0毫米到0.4毫米，并且氦原子在大约100下均匀地灌输到厚度为0.3mm的样品上，大约为85 appm灌输到85 appm 的F82H钢的DBTT改变大约为1511。在RT下测的F82H钢的SP数据表2给出。在Kimura的相似回旋加速器氦灌输实验里，在JLM-1钢12的情况下，由于120 appm的氦引起的DBTT的变化大约为20。在我们的以前的数据里，在F82H钢里的DBTT的变化与氦浓度的比大约为0.18 appm He，在JLM-1钢12的情况下Kimura数据的比为0.220.18appm He。这两个在不同的马氏永磁体氦对DBTT的影响的数据非常相似。使用1/3CVN标准由SP数据和1/3CVN数据的关系来决定的DBTT13，在F82H钢里的我们的以前的SP实验获得的DBTT可能被修改为37.5 。在0.03 dpa下，由位移损害引起的DBTT的变化可以被从中子照射实验14的其他数据计算，且其值估计大约为5。在F82H钢的实验里，0.03 dpa的由于位移损害的DBTT的改变值为6，且通过这项研究获得的值与其它研究的结果非常接近。因此，在1/3CVN中，由于85 appm的氦生产的DBTT的变化可能大约为32。现在的研究可以得到同样的结果。另一方面，在马氏永磁体的掺杂硼或镍的实验 ，可以得到关于同位素实验的由氦生产的DBTT的变化的同样的结果。不过，硼或者镍的参和物可能引起严重的辐射脆化。在这个实验过程中，没有像以前研究报告的那样对DBTT的化学额外要素16,17 、DBTT的变化11、照射淬水的增加18,19 以及缺陷群20,21 的影响。因此，断定氦生产能影响DBTT的变化。5.Charpy冲击试验图7显示了使用20 ppm N (low N)的t/2-CVN、1/3CVN and t/2-1/3CVN样品的作为温度函数的样品尺寸的Charpy冲击能的依赖性。断裂面前横截面的上面架子能源是随着样品尺寸的减小而减小的。t / 2CVN、1/3CVN和t / 2-1/3CVN的DBTT分别为82, 104 and 140。众所周知，DBTT与样品(B)的宽度和样品(b)槽口下面的韧带长度有很大关系2225。在反应堆压力容器钢的全长和子长度样品的DBTT的关系如下所示： （1）上式中，和分别为Charpy冲击样品的全长和子长度的过渡温度22。在这项研究过程中的B和b的DBTT值在表3给出，且1/3CVN和t / 2-1/3CVN的DBTT按照式（1）的计算大约为130和-141。t / 2-1/3CVN的DBTT的估计值正好与在这研究内的F82H钢试验数据一致，但是1/3CVN的DBTT估计值比目前试验数据的值低。F82H钢的DBTT比RPV钢的低，且其它因素，如样品的尺寸和密度可能与DBTT的大小相互关系有关。RAF钢的全长和子长度样品的DBTT的实验相互关系还需进一步研究。 6. 摘要(1) 新弯曲测试机器一直被发展并获得F82H钢的破裂行为t/2-1/3PCCVN的20毫米长的小弯曲样品和9毫米长的DFMB和0.18DCT 类型的磁盘和断裂行为在进行检查。(2) F82H钢的试样尺寸对DBTT的影响通过使用t / 2CVN，1/3CVN和t / 2-1/3CVN被检查， 并且t / 2-1/3CVN 和1/3CVN的DBTT比t/2-CVN的DBTT要小。(3) 由于氦生产和位置损害，DBTT手段被小钻床测试检查。致谢作者想对日本原子能研究所的M. Ando和T. Sawai博士表达诚挚的感谢，感谢他们在Oarai JAERI的Oarai里帮助讨论和参加JMTR和JMTR操作的原子核实验室。参考文献1 W.R. Corwin, G.E. Lucas (Eds.), The Use of Small-Scale Specimens for Irradiated Testing, ASTM-STP-888, American Society for Testing and Materials, Philadelphia, PA, 1986.2 W.R. Corwin, G.E. Lucas (Eds.), Small Specimens Test Techniques,ASTM-STP-1328, American Society for Testing and Materials, Philadelphia, PA, 1998.3 M. Sokolov, G.E. Lucas, J. Landes, 4th Symposium on Small Specimen Test Techniques STM-STP-1418, American Society for Testing and Materials, Philadelphia, PA, 2003.4 G.E. Lucas, The development of small specimen mechanical test techniques, J. Nucl. Mater. 117 (1983) 327339.5 P. Jung, A. Hishinuma, G.E. Lucas, H. Ullmaier, Recommendation of miniaturized techniques for mechanical testing of fusion materials in an intense neutron source, J. Nucl. Mater. 232(1996) 186205.6 R. Odette, K. Edsinger, G.E. Lucas, E. Donahue, in: W.R.Corwin, S.T. Rosinski, E. van Walle (Eds.), Small Specimens Test Techniques, ASTM-STP-1328, American Society for Testing and Materials, Philadelphia, PA, 1998, pp. 298321.7 G.R. Odette,Acleavage toughness master curve model, J. Nucl. Mater. 283287 (2000) 120127.8 H. Matusi, IFMIF Status and Perspectives, Presented at ICFRM-10.9 G.E. Lucas, G.R. Odette, K. Edsinger,B.Wirth, J.W. Sheckherd,On the role of strain rate, size and notch acuity on toughness:a comparison of two martensitic stainless steels, ASTM STP 1270 (1996) 790814.10 T. Ishii,M.Ohmi, J. Saito,T. Hoshiya, N. Ooka, S. Jitsukawa,M. Eto, Development of a small specimen test machine to evaluate irradiation embrittlement of fusion reactor materials, J. Nucl.Mater. 283287 (2000) 10231027.11 E.Wakai, S. Jitsukawa, H. Tomita, K. Furuya, M. Sato, K. Oka, T. Tanaka, F. Takada, T. Yamamoto, Y. Kato, Y. Tayama, K. Shiba, S. Ohnuki, Radiation hardening and embrittlement due to He production in F82H steel irradiated at 250 C in JMTR,J. Nucl. Mater., in press.12 A. Kimura, T. Morimura, R. Kasada, H. Matsui, A. Hasegawa,K. Abe, Evaluation of ductilebrittle transition behavior of helium-implanted reduced activation 9Cr-2W martensitic steel by small punch tests, Effects Radiat. Mater. STP 1366 (2000) 626641.13 M. Eto, H. Takahashi, T. Misawa, M. Suzaki, Y. Nishiyama, K. Fukaya, S. Jitsukawa, Development of a miniaturized bulge test (small punch test) for post-irradiation mechanical property evaluation, Small Specimen Test Techniques, ASTM STP 1204(1993) 241255.14 M. Rieth, B. Dafferener, H.-H. Rohrig, Embrittlement behavior of different international low activation alloys after neutron irradiation, J. Nucl. Mater. 258 (1998) 11471152.15 K. Shiba, I. Ioka, J.P. Robertson, M. Suzuki, A. Hishinuma, Mechanical properties of neutron irradiated F82H, in: Euromat- 96, 1996, pp. 265272.Short communicationWrinkling behaviour of interstitial free steel sheetswhen drawn through tapered diesR. Narayanasamya,*, C. Sathiya NarayananbaDepartment of Production Engineering, National Institute of Technology, Tiruchirappalli 620 015, Tamilnadu, IndiabDepartment of Production Engineering, J.J. College of Engineering and Technology, Tiruchirappalli 620 009, Tamilnadu, IndiaReceived 4 January 2005; accepted 8 July 2005Available online 2 September 2005AbstractWrinkling is a mode of failure commonly observed in the forming of sheet metals during deep draw operation. An experimentalstudy on wrinkling behaviour of interstitial free (IF) steels through conical and tractrix dies is discussed in this paper. Mechanicalproperties and drawability parameters of these IF steels were determined and they were correlated with the wrinkling behaviour. Thelimiting draw ratio (LDR) of these steel sheets were related to the sheet thickness, the ratio of punch diameter to sheet thickness, thenormal anisotropy and the non-dimensional parameter (which involves punch diameter, sheet thickness, normal anisotropy andstrain hardening exponent). The above study of wrinkling behaviour was carried out under two different conditions namely lubri-cated and non-lubricated and they were compared. From the study, it is clear that the LDR could be related to the above-mentionedparameters.? 2005 Elsevier Ltd. All rights reserved.Keywords: IF steel; Wrinkling; Conical die; Tractrix die1. IntroductionWrinkles are often observed in sheet metal formingprocesses. The presence of wrinkles is unacceptable forthe final product. In the recent years, the thinner guagesheets with high strength are used in order to reduce theweight of the products which leads to the formation ofbuckles and wrinkles during the forming operations.The researchers aim to avoid such wrinkles during sheetmetal forming. Hill?s 1 bifurication criterion can beused to predict the formation of wrinkles. The onset offlange wrinkling was analysed by Needleman 2 byusing Swift cup test. Several theoretical and experimen-tal works have been carried out on the wrinkling behav-iour of different materials under different conditions.Kim and Son 3 evaluated wrinkling limit diagram(WLD) of anisotropic sheet by numerical analysis. JoaoPedro de Magalhaes Correia and Gerard Ferron 4investigated the influence of plastic anisotropy on theonset of wrinkling. Narayanasamy and Sowerby 5examined the wrinkling behaviour of stainless steel 304grade, dual phase steel and aluminium killed drawingquality steel. In this work, the wrinkling behaviour ofinterstitialfree(IF)steelswiththickness0.6 mm,0.85 mm coated and non-coated, 0.9, 1.2 and 1.6 mmhave been studied using conical die and tratrix die usinga double action hydraulic press of capacity 2000 kN.Interstitial free steels are newly developed steels havingverymuchlessamountofcarbonandnitrogen.Although aluminium alloys are used for automobilesapplications due to their lightweight, which contributes0261-3069/$ - see front matter ? 2005 Elsevier Ltd. All rights reserved.doi:10.1016/j.matdes.2005.07.005*Corresponding author. Tel.: +91 0431 2501801; fax: +91 04312500133.E-mail addresses: narayan (R. Narayanasamy), csathiyanarayananyahoo.co.in (C.S. Narayanan)./locate/matdesMaterials and Design 28 (2007) 254259Materials& Designin the saving of fuel, the demand for vehicle safetymakes the users to prefer a material to increase theweight of the automobile body and crashing strengthof the vehicle 6,7. Interstitial free (IF) steels are newlydeveloped materials and have some excellent properties.They are suitable for galvanneal coatings, which isrequired for automotive body works as given elsewhere.Interstitial free steels are free from carbide precipitatesat the grain boundaries 8. So they have excellent work-ability and mechanical properties (due to the presence ofalloying elements such as Mn and Si). Interstitial freesteels are Ti and/or Nb stabilized and they have gooddrawability 9. In the recent years, many works havebeen carried out to develop interstitial free steels withimproved properties by understanding the microstruc-tural aspects, which control the deformation behaviourof interstitial free steels as explained elsewhere 10,11.In present work, the wrinkling behaviour of IF steelsand their suitability to drawing process is studied withthe help of experimental work using conical and tractrixdies under lubricated and non-lubricated conditions.2. Experimental workUsing the above-said sheets, uniaxial tensile testswere conducted by preparing specimens at 0?, 45? and90? orientation to the rolling direction from each sheetusing Hounsfield tensometer. The load vs. extensiondata were obtained from these test. The importantparameters namely the strain hardening exponent (n),the plastic strain ratio (R) and the strength coefficient(K) along the three directions mentioned above werefound out from the tensile tests as explained in 5.The normal anisotropy ?R and the planer anisotropy(DR) were calculated from the R values determinedalong three directions mentioned above using theexpression given below?R 0.25R0 R45 R90.1The conical and tractrix dies used in the experimentare shown in Figs. 1 and 2, respectively. Using these diesdifferent lubricating conditions have been explored.In order to determine the limiting diameter, for agiven sheet thickness the diameter of the circular blankswas increased gradually in successive tests until wrinklesoccurs. A grid circle pattern was printed on the blanksto measure the radial strain (er) and hoop strain (eh) dur-ing the drawing operation.3. Results and discussionThe normal anisotropy and strain hardening expo-nent values of the steel sheets taken for the study are gi-ven in the Table 1. The limiting draw ratio and limitingdiameter when the sheets are drawn in conical die areshown in Table 2.The limiting draw ratio and limiting diameter whenthe sheets are drawn in tractrix die are shown in Table 3.NomenclatureLDRlimiting draw ratio (limiting blank diameter/punch diameter)rtrue stressetrue strainKstrength coefficientehhoop strainerradial strainnstrain hardening exponentRnormal anisotropydppunch diametert0initial sheet thicknessIF steel interstitial free steelder/ehplastic strain increment ratioFig. 1. Conical die.R. Narayanasamy, C.S. Narayanan / Materials and Design 28 (2007) 254259255The variation of limiting draw ratio for IF steel withsheet thickness when drawn in conical die is shown inFig. 3. The variation of limiting draw ratio for IF steelwith sheet thickness when drawn in tractrix die is shownin Fig. 4. In both cases, the limiting draw ratio increaseswith the thickness of the sheet.Fig. 5 shows the variation of limiting draw ratio withdp/t0when the sheet is drawn in conical die. Fig. 6 showsthe variation of limiting draw ratio with dp/t0when thesheet is drawn in tractrix die. As the dp/t0ratio increases,the limiting draw ratio decreases in both cases. Fig. 7shows the variation of limiting draw ratio with normalanisotropy in conical die. Fig. 8 shows the variation oflimiting draw ratio with normal anisotropy in tractrixFig. 2. Tractrix die.Table 1Normal anisotropy and strain hardening exponent valuesSheet metalInitialthickness (mm)Averagen-valueAverageR-valueIF steel non-coated0.850.34431.8770IF steel coated0.850.29191.9726IF steel0.60.28281.3208IF steel0.90.30081.1488IF steel1.20.26710.9704IF steel1.60.33151.2347Table 2Values of the limiting draw ratio using conical dieMaterial and conditionInitial thicknessin mmLimitingdiameter in mmLDRIF steel non-coated0.851052.100IF steel coated0.851002.000IF steel non-lubricated0.6801.600IF steel lubricated0.9851.700IF steel non-lubricated1.21002.000IF steel lubricated1.2851.700IF steel lubricated1.61252.500Table 3Values of the limiting draw ratio using tractrix dieMaterial and conditionInitial thicknessin mmLimiting diameterin mmLDRIF steel0.6801.600IF steel0.9901.800IF steel coated0.85951.900IF steel non-coated0.851052.100IF steel1.21102.200IF steel1.61302.600I.F. Steelsy = 0.7084x2 - 0.9144x + 2.06821.01.82.01.7Sheet Thickness in mmLimiting Draw Ratio FORD INDIA LTD.TISCO.CONICAL DIE DEEP DRAWWRINKLING AREASAFE AREAFig. 3. Variation of limiting draw ratio with sheet thickness in conicaldie.I.F. Steelsy = -0.1064x2 + 1.1823x + 0.96841.01.82.02.81.7Sheet Thickness in mmLimiting Draw RatioTRACTRIX DIE DEEP DRAWWRINKLING AREASAFE AREA FORD INDIA LTD.TISCO.Fig. 4. Variation of limiting draw ratio with sheet thickness in tractrixdie.256R. Narayanasamy, C.S. Narayanan / Materials and Design 28 (2007) 254259I.F. Steelsy = -0.1992x2 + 0.7717x + 1.292.02.82.1Normal Anisotrophy Value ( R )Limiting Draw RatioCONICAL DIE DEEP DRAWSAFE AREAWRINKLING AREA FORD INDIA LTD. TISCO.Fig. 7. Variation of limiting draw ratio with normal anisotropy inconical die.I.F. Steelsy = 0.5871x2 - 1.9098x + 3.481.01.82.02.83.02.1Normal Anisotrophy Value ( R )Limiting Draw RatioTRACTRIX DIE DEEP DRAWWRINKLING AREASAFE AREA FORD INDIA LTD. TISCO.Fig. 8. Variation of limiting draw ratio with normal anisotropy intractrix die.I.F. Steelsy = 0.0002x2 - 0.033x + 3.11961.01.82.02030405060708090dp/toLimiting Draw RatioCONICAL DIE DEEP DRAWWRINKLING AREASAFE AREA FORD INDIA LTD. TISCO.Fig. 5. Variation of limiting draw ratio with dp/t0in conical die.I.F. Steelsy = 0.0002x2 - 0.0453x + 3.741.01.82.02.82030405060708090dp/toLimiting Draw RatioTRACTRIX DIE DEEP DRAWWRINKLING AREASAFE AREA FORD INDIA LTD. TISCO.Fig. 6. Variation of limiting draw ratio with dp/t0in tractrix die.I.F. Steelsy = 2E-05x2 - 0.0094x + 3.08061.01.82.02.83.0100150200250300350400450Non-Dimensional Parameter ( dp / to ) ( R / n )Limiting Draw RatioCONICAL DIE DEEP DRAWWRINKLING AREASAFE AREA FORD INDIA LTD. TISCO.Fig. 9. Variation of limiting draw ratio with non-dimensional param-eter involving punch diameter, initial thickness, normal anisotropy andstrain hardening exponent in conical die.I.F. Steelsy = 1E-05x2 - 0.0094x + 3.38081.01.82.02.83.0100150200250300350400450Non-Dimensional Parameter ( dp / to ) ( R / n )Limiting Draw RatioTRACTRIX DIE DEEP DRAWWRINKLING AREASAFE AREA FORD INDIA LTD. TISCO.Fig. 10. Variation of limiting draw ratio with non-dimensionalparameter involving punch diameter, initial thickness, normal anisot-ropy and strain hardening exponent in tractrix die.R. Narayanasamy, C.S. Narayanan / Materials and Design 28 (2007) 254259257die. While drawing in conical die, the limiting draw ratioincreases with normal anisotropy value. Fig. 9 shows thevariation of limiting draw ratio with non-dimensionalparameter involving punch diameter, initial thickness,normal anisotropy and strain hardening exponent inconical die. Fig. 10 shows the variation of limiting drawratio with non-dimensional parameter involving punchdiameter, initial thickness, normal anisotropy and strainhardening exponent in tractrix die. The limiting draw ra-tio decreases with increasing value of the above saidnon-dimensional parameter. However, the above resultsshows that limiting draw ratio for the IF steels is higherwhen they are drawn in tractrix die. Fig. 11 shows thevariation of plastic strain increment ratio for IF steelswhen they are drawn in conical die and the variationof plastic strain increment ratio for IF steels when theyare drawn in tractrix die is shown in Fig. 12. The plasticstrain increment ratio increases linearly in case of coni-cal die and the variation is not clear in case of tractrixdie. Fig. 13 shows the variation of plastic strain incre-ment ratio for prestrained IF steel sheets. This alsoshows the increasing nature of plastic strain incrementratio with increasing value of dp/t0ratio.4. ConclusionFrom the above results, the following conclusionhave been made. The limiting draw ratio increases withthe increasing thickness and increasing value of plasticstrain increment value. The limiting draw ratio decreaseswith increasing value of dp/t0and non-dimensionalparameter involving punch diameter, initial thickness,normal anisotropy and strain hardening exponent. Thisnature i