标题：Effect of trace boron on low temperature impact toughness of hot-rolled Nb-added HSLA H-beams
作者：Cui, Guotao; Wang, Zuocheng; Sun, Tao; Guo, Weimin; Gao, Junqing
作者机构：[Cui, Guotao; Wang, Zuocheng; Sun, Tao; Guo, Weimin] Shandong Univ, Key Lab Liquid Solid Struct Evolut & Proc Mat, Minist Educ, 17923 Jingshi Rd, Jina 更多
会议名称：2nd International Conference on Civil Engineering, Architecture and Building Materials (CEABM 2012)
会议日期：MAY 25-27, 2012
来源：ADVANCED BUILDING MATERIALS AND SUSTAINABLE ARCHITECTURE, PTS 1-4
关键词：Boron; High Strength Low Alloy (HSLA); H-beam; Low Temperature Impact; Toughness; Fracture Appearance Transition Temperature (FATT)
摘要：In this research, trace boron (4ppm, 8ppm, 11ppm) was added into the Nb-added HSLA H-beams. The impact toughness of H-beams with/without boron was examined by Charpy impact test (V-notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results prove that the absorbed impact energy at -40 degrees C for the 4ppm, 8ppm, 11ppm boron-added steels respectively reaches up to 80J, 126J, 85J from 15J and H-beams with boron have a lower FATT than that without boron. It is also found that the total oxygen content affects the absorbed impact energy to a certain extent. It is discovered by transmission electron microscope (TEM) that boron mainly exists in solid solution state, except that a little amount of Fe-23(C, B)(6) is formed at the grain boundaries, and the distribution of Nb(C, N) is also influenced by boron addition.