Enhanced strength-ductility synergy of bimetallic laminated steel structure of 304 stainless steel and low-carbon steel fabricated by wire and arc additive manufacturing
Enhanced strength-ductility synergy of bimetallic laminated steel structure of 304 stainless steel and low-carbon steel fabricated by wire and arc additive manufacturing
复制标题
线材和电弧增材制造304不锈钢和低碳钢双金属层压钢结构增强强塑协同
DOI：
10.1016/j.msea.2022.143984
复制
发表时间：
2022-09-20
期刊：
影响因子：
6.4
通讯作者：
Ao, Sansan
中科院分区：
文献类型：
--
作者：
Chen, Yi;Zuo, Xinde;Ao, Sansan
与传统的高强度钢生产技术相比，焊丝和电弧添加剂制造(WAAM)由于其低成本和高生产率而受到越来越多的关注。通过在Q345基片上交替沉积304不锈钢(304 SS)和低碳钢(LCS)，利用WAAM制备了具有增强强塑性协同效应的双金属叠层钢(BLSS)。对添加剂制备的BLSS的组织和力学性能进行了详细的研究。304不锈钢层由马氏体组成，不同于单一的304不锈钢组织中分布在奥氏体基中的蠕虫状铁素体。而LCS层与单一LCS组织相比没有明显的变化，只是细化了块状铁素体。同时，LCS层与304不锈钢层之间的界面处形成了细小的颗粒。不同层间元素含量、物相组成和晶粒度的不同导致了这种BLSS在不同加载方向上力学性能的变化。纵向(Y)方向的抗拉强度和延伸率分别达到999.8 Mpa和28.2%，两者的延伸率相差很大，强度几乎是单质304不锈钢和LCS组织的两倍。用数字图像相关法(DIC)观察了BLSS在拉伸过程中的应变分布，发现在横向(Z)方向有明显的应力集中，导致其拉伸性能比Y方向有所下降。不同加载方向试件的断口形貌分析表明，试件呈现脆-韧混合断裂模式。我们的工作为制备具有优异力学性能的BLSs提供了一种可行而灵活的方法，在建筑和土木工程结构等领域具有潜在的应用前景。
Wire and arc additive manufacturing (WAAM) has received increasing attention due to its low cost and high productivity compared to traditional techniques for manufacturing high strength steels. In the present work, WAAM was used to fabricate bimetallic laminated steel structure (BLSS) with enhanced strength-ductility synergy by alternately depositing 304 stainless steel (304 SS) and low carbon steel (LCS) on Q345 substrate. The microstructure and mechanical properties of additive manufactured BLSS were investigated in detail. The 304 SS layer is composed of martensite, different from the vermicular ferrite distributed in the austenite matrix of the single-304 SS structure. While the LCS layer has no obvious change compared to the single-LCS structure, except for the refinement of the blocky ferrite. Meanwhile, fine grains formed at the interface between the LCS and 304 SS layers. The differences in element content, phase constituent and grain size between different layers lead to changes in the mechanical properties of this BLSS along different loading directions. The tensile strength and elongation in the longitudinal (Y) direction reached 999.8 MPa and 28.2%, respectively, where the strength was almost twice that of single-material 304 SS and LCS structure with the elongation between them. Digital image correlation (DIC) was used to observe the strain distribution of the BLSS during tensile process, and a significant stress concentration was observed in the transversal (Z) direction, resulting in a decrease in its tensile properties compared to the Y direction. Fracture topography analysis of specimens with different loading directions revealed a brittle-ductile mixed fracture mode. Our work provides a feasible and flexible method for the fabrication of BLSS with superior mechanical properties, which have potential applications in fields such as architectural and civil engineering structures.