Influence of Ti and Nb on the Strength–Ductility–Hole Expansion Ratio Balance of Hot-rolled Low-carbon High-strength Steel Sheets
Influence of Ti and Nb on the Strength–Ductility–Hole Expansion Ratio Balance of Hot-rolled Low-carbon High-strength Steel Sheets
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DOI：
10.2355/isijinternational.52.151
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发表时间：
2012-01
影响因子：
1.8
通讯作者：
K. Kamibayashi;Y. Tanabe;Y. Takemoto;I. Shimizu;T. Senuma
中科院分区：
文献类型：
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作者：
K. Kamibayashi;Y. Tanabe;Y. Takemoto;I. Shimizu;T. Senuma
为了满足高强度钢板的强-塑性-扩孔率平衡要求，开发了由大量细小弥散析出相强化的铁素体或贝氏体铁素体基体组成的高强度钢板，研究了析出相形成元素Ti和Nb对这些钢板的强-塑性-扩孔率平衡的影响。含Ti钢的强塑性与扩孔率的平衡比含Nb钢的强塑性与扩孔率的平衡好上级。从显微组织、织构、穿孔表面状况、硫化物的形成、扩孔过程中裂纹的形核和扩展行为等多个角度讨论了加Ti钢优越性的原因，我们得出结论，强度-延性-含Nb钢的扩孔率平衡主要是由于大织构团的形成和MnS的不利影响。根据这些推论，我们提出了Ti和Nb的组合添加，并成功地改善了先进高强度钢的强度-塑性-扩孔率平衡。
To satisfy the demand for high-strength steel sheets with excellent strength–ductility–hole expansion ratio balance, high-strength steels consisting of a ferrite or bainitic ferrite matrix strengthened by a large amount of finely dispersed precipitates have been developed.In this study, the influence of the precipitation-forming elements Ti and Nb on the strength–ductility–hole expansion ratio balance of these steels has been investigated. The strength–ductility–hole expansion ratio balance of steel with Ti added was superior to that with Nb added. The reason for the superiority of steel with added Ti was discussed from various viewpoints such as microstructure, texture, the condition of the pierced surface, sulphide formation, the nucleation and propagation behaviour of cracks during hole expansion, etc. We concluded that the inferior strength–ductility–hole expansion ratio balance of the steel with added Nb was mainly caused by the formation of large textural colonies and a detrimental influence of MnS. From these inferences, we proposed a combined addition of Ti and Nb, and succeeded in improving the strength–ductility–hole expansion ratio balance of the advanced high-strength steel.