Experimental investigation of the mechanical response of laser-welded dissimilar blanks from advanced- and ultra-high-strength steels
Experimental investigation of the mechanical response of laser-welded dissimilar blanks from advanced- and ultra-high-strength steels
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DOI：
10.1016/j.matdes.2015.11.057
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发表时间：
2016-01
影响因子：
8.4
通讯作者：
H. Gong;S. Wang;Paul Knysh;Y. Korkolis
中科院分区：
文献类型：
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作者：
H. Gong;S. Wang;Paul Knysh;Y. Korkolis
我们报道了一种先进和超高强度汽车用钢的异种拼焊板(TWB)的机械响应实验结果。这两种钢分别是双相钢DP 780和DP 1180。首先，我们介绍了这两种基材的拉伸和各向异性特性。在测试过程中，使用数字图像相关(DIC)和红外热成像(IR)技术获得了应变和温度的全场。后者是关键，因为这两种材料都容易变形引起的加热，这会在试验截面上建立一个温度梯度，进而限制了观察到的延性。然后我们描述了激光焊接设备，以及焊缝周围的显微组织观察和测量。随后，我们测试了拼焊板的拉伸试件，焊缝横向取向为45°，平行于加载的纵向。我们详细介绍了破坏模式和宏观载荷-位移响应。此外，借助DIC和IR图像，我们探索了局部应变场和温度场及其演化，并将其与TWB拉伸试件的整体响应和破坏关联起来。
We report experimental results on the mechanical response of dissimilar tailor-welded blanks (TWB) from an advanced- and an ultra-high-strength steel for automotive applications. These are the dual-phase steels DP 780 and DP 1180, respectively. First, we present the tensile and anisotropic properties of the two base-materials. During testing, the full-fields of strain and temperature are acquired, using the Digital Image Correlation (DIC) and Infrared Thermography (IR) techniques. The latter is critical, since both materials are prone to deformation-induced heating, which establishes a temperature gradient along the test-section, and which in turn limits the ductility observed. We then describe the laser-welding apparatus, and microstructural observations and measurements around the weld-seam. Subsequently, we test tensile coupons from the TWBs, with the weld-seam oriented transversely, 45° and parallel to the longitudinal direction of the loading. We detail the failure modes and the macroscopic load–displacement responses. Furthermore, with the aid of the DIC and IR images, we probe the local strain and temperature fields and their evolution, and correlate these to the overall response and failure of the TWB tensile coupons.