The Effects of Cooling Mode on the Properties of Ti–Nb Microalloyed High-strength Hot-rolled Steels
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2019年第3期
论文作者：朱敏 徐光 ZHOU Mingxing HU Haijiang
文章页码：692 - 697
摘 要：The industrial trials of two cooling modes, i e, water cooling in forepart + air cooling in later part（WAC） and air cooling in forepart + water cooling in later part（AWC）, were carried out for a TiNb microalloyed steel. The average cooling rates and coiling temperature were the same for two modes. The continuous cooling transformation（CCT） curve of the tested steel was drawn. The effects of the cooling mode on the microstructure, precipitates, and properties of the steels were investigated. Results show that the strength of the steel in the WAC mode is significantly larger than that in the AWC mode, mainly because the smaller the grain size, the more and finer the grain precipitates. Therefore, when the average cooling rate is constant, the fast cooling in the forepart is an effective method to increase the strength of steels. However, the increase in the strength is accompanied by the decrease in toughness, so that the toughness of the steel should be considered when changing the cooling mode.
朱敏1,2，徐光1，ZHOU Mingxing1，HU Haijiang1
1. The State Key Laboratory of Refractories and Metallurgy,Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology2. Research and Development Center of Wuhan Iron and Steel (Group) Corp
摘 要：The industrial trials of two cooling modes, i e, water cooling in forepart + air cooling in later part（WAC） and air cooling in forepart + water cooling in later part（AWC）, were carried out for a TiNb microalloyed steel. The average cooling rates and coiling temperature were the same for two modes. The continuous cooling transformation（CCT） curve of the tested steel was drawn. The effects of the cooling mode on the microstructure, precipitates, and properties of the steels were investigated. Results show that the strength of the steel in the WAC mode is significantly larger than that in the AWC mode, mainly because the smaller the grain size, the more and finer the grain precipitates. Therefore, when the average cooling rate is constant, the fast cooling in the forepart is an effective method to increase the strength of steels. However, the increase in the strength is accompanied by the decrease in toughness, so that the toughness of the steel should be considered when changing the cooling mode.
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