Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part I. Deformation modes
Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part I. Deformation modes
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热镀锌钢板镀锌层的变形和损伤机制：第一部分：变形模式
DOI：
10.1007/s11661-004-0007-x
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
J. Mataigne
中科院分区：
文献类型：
--
作者：
Rodolphe Parisot;S. Forest;A. Pineau;F. Grillon;Xavier Demonet;J. Mataigne
锌基涂料广泛用于汽车工业中钢板产品的防腐蚀。本文的目的是研究在拉伸、平面应变拉伸和膨胀载荷作用下，在三种不同微观结构的薄（8 μm）锌涂层在无铬钢基体上的变形模式。损坏机制在配套文章中讨论。将未回火冷轧涂层（标记为NSK）、回火冷轧涂层（标记为SK）和再结晶涂层的锌晶粒中的塑性滑移和孪晶活性与相应的块状低合金锌材料的响应进行比较。NSK和SK涂层中的面内晶粒尺寸范围为300至600 µm，而再结晶涂层和本体材料中的面内晶粒尺寸约为30 µm。涂层表现出强烈的晶体织构，c轴通常垂直于片平面。基体滑移是体锌和再结晶镀层的主要变形机制，而锥体π2滑移和机械孪晶是NSK和SK镀层的主要变形方式。这些结果，从一个广泛的，定量的滑移线分析结合电子背散射衍射（EBSD）测量，解释了基板的约束效应。这种效果是成功地模拟使用一个简单的泰勒样多晶的方法。再结晶的涂层表现得很像块体材料。解释NSK和SK涂层之间的晶粒尺寸效应，一方面，和再结晶涂层，另一方面，需要一个完整的三维有限元分析的多晶涂层在这项工作中提供。模拟结果表明，强应变梯度可以在再结晶涂层中从界面发展到表面，这是在NSK和SK涂层的情况下。
Zinc-based coatings are widely used for protection against corrosion of steel-sheet products in the automotive industry. The objective of the present article is to investigate the deformation modes at work in three different microstructures of a thin (8 µm) zinc coating on an interstitial-free steel substrate under tension, plane-strain tension, and expansion loading. Damage mechanisms are addressed in a companion article. The plastic slip and twinning activity in the zinc grains of an untempered cold-rolled coating (labeled NSK), a tempered cold-rolled coating (labeled SK), and a recrystallized coating are compared with the response of the corresponding bulk low-alloyed zinc material. The in-plane grain size in the NSK and SK coatings ranges from 300 to 600 µm, vs about 30 µm in the recrystallized coating and bulk material. The coatings exhibit a strong crystallographic texture, with the c-axis generally normal to the sheet plane. Basal slip is shown to be the main deformation mechanism in bulk zinc and the recrystallized coating, whereas pyramidal π2 slip and mechanical twinning are found to be major modes in the NSK and SK coatings. These results, obtained from an extensive, quantitative slip-line analysis combined with electron backscattered diffraction (EBSD) measurements, are explained by the constraining effect of the substrate. This effect is successfully modeled using a simple Taylor-like polycrystalline approach. The recrystallized coating behaves much like the bulk material. The interpretation of this grain-size effect between the NSK and SK coating, on the one hand, and the recrystallized coating, on the other hand, requires a full three-dimensional finite-element analysis of the multicrystalline coating provided in this work. The simulations show that strong strain gradients can develop in the recrystallized coating from the interface to the surface, which is not the case in the NSK and SK coatings.