Comparison of microstructure and phase transformation of laser-welded joints in Al-10wt%Si-coated boron steel before and after hot stamping
Comparison of microstructure and phase transformation of laser-welded joints in Al-10wt%Si-coated boron steel before and after hot stamping
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DOI：
10.1016/j.matchar.2017.02.007
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发表时间：
2017-06-01
影响因子：
4.7
通讯作者：
Kang, Chung-Yun
中科院分区：
文献类型：
--
作者：
Yoon, Tae-Jin;Oh, Myeong-Hwan;Kang, Chung-Yun
研究了Al-10wt%Si涂层硼钢激光焊接接头热冲压热处理前后的偏析和组织相变特征。熔合区的铝偏析分为两种类型。第一种类型不均匀地分布在熔合区中，Al浓度为128wt%-0.30wt%。该区域的显微组织包括马氏体（在贫Al区域中）和贝氏体（在富Al区域中）。第二种类型是沿沿着熔合边界以长彗星形状形成的，具有高Al浓度（8.24-15.10重量%）。该区域的显微组织包括具有单相的Fe-3（Al，Si）。激光焊接熔合区热冲压热处理前后的显微组织基本相同。由于在热冲压热处理过程中Al向母材扩散，该区域中的Al含量降低。另一方面，在热冲压工艺之后，在熔合边界处可发生相变。这种转变导致从Fe-3（Al，Si）相到多边形铁素体相的微观结构变化。结果表明，偏析区中的铝含量影响熔合区和熔合区中铁素体的形成。(C)2017由Elsevier Inc.出版
The features of segregation and structure phase transformation of laser-welded joints in Al-10wt%Si-coated boron steel before and after hot stamping heat treatment were studied. Al segregation in the fusion zone is divided into two types. The first type is distributed unevenly in the fusion zone with a 128 wt%-0.30 wt Al concentration. The microstructure of this zone comprises martensite (in Al-deficient zones) and bainite (in Al-rich zones). The second type is formed along the fusion boundary in a long comet shape with a high Al concentration (8.24-15.10 wt%). The microstructure of this zone comprises Fe-3(Al,Si) with a single phase. The microstructures in the laser-welded fusion zone before and after hot stamping heat treatment were identical. The Al content in this zone decreases because Al diffuses toward the base metal during hot stamping heat treatment. On the other hand, after the hot stamping process, phase transformations can occur at the fusion boundary. Such transformations lead to microstructural changes from the Fe-3(Al,Si) phase to the polygonal ferrite phase. It is clear that the Al contents in the segregation zone affect the ferrite formation in the fusion boundary and zone. (C) 2017 Published by Elsevier Inc.