Microstructure and Mechanical Properties of ULCB Steels Affected by Advanced TMCP Technology

Abstract:

Good combination of high strength and high toughness has been considered as a critical factor of ultra-high strength steel plates. In this paper, a novel high strength steel plate of HSLA type containing Cu with 910MPa yield strength and 1163MPa tensile strength has been developed using an advanced TMCP (thermo-mechanical control processing) technology. The steel plates provide excellent combination of high strength, toughness and deformability. Microstructural evolution and mechanical properties of this steel during hot-working have been investigated. It is demonstrated that, at the relatively higher finish rolling temperature and cooling rate, the microstructure consists of acicular and granular bainite structures and a small amount of low bainite /martensite whose lath width is approximately 200~300nm. For the as-rolled conditions, despite the high strength and so low yield ratio, impact energy about 154J and fully ductility fracture at -90°C can still be obtained as documented for as-hot rolled plates.

• Periodical: Materials Science Forum (Volume 689)
• Pages: 289-295
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.689.289
• Online since: June 2011
• Authors: Zi Yong Hou, Yun Bo Xu, Di Wu, Wei Hua Sun, She E Hu, Guo Dong Wang
• Keywords: Advanced TMCP Technology, Microstructure, ULCB Steel, Ultra High Toughness, Ultra-High Strength

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