摘要
屈强比是桥梁用钢的重要性能指标。研究了热轧后的冷却方式,包括普通的连续冷却、延迟冷却和分段冷却,对16 mm厚桥梁用Q500qE钢板屈强比的影响。结果表明:热轧后连续冷却的钢板组织为单一的贝氏体,强度较高,屈强比偏高;分段冷却,即热轧后水冷至670~740℃,以避免晶粒长大,再以1~3℃/s的冷速空冷至600~680℃,以获得部分铁素体,最后以大于15℃/s的冷速水冷至350℃以下,使剩余奥氏体完全转变为贝氏体,钢板的组织为铁素体+贝氏体双相,屈强比较低,符合要求。
Yield ratio is an important performance index for steel used to build bridge.The effect of cooling processes after hot-rolling,including conventional continuous cooling,delay cooling,and stepped cooling,on yield ratio of 16-mm-thick Q500qE bridge steel plate was investigated.The result showed that the plate hot rolled and immediately cooled exhibited single-phase bainite and relatively higher strength and yield ratio;and that the stepped cooling process,which consisted of water-cooling after hot-rolling to 670℃to 740℃for the purpose of avoiding grain growth,then cooling at 1℃/s to 3℃/s to 600℃to 680℃for the purpose of securing a portion of ferrite,and finally water-cooling at more than 15℃/s to below 350℃to allow remaining austenite all to transform into bainite,to cause the plate to produce dual-phase structure consisting of ferrite and bainite,with the yield ratio being lower,and conforming with the requirement.
作者
武凤娟
杨浩
邵伟
曲锦波
WU Fengjuan;YANG Hao;SHAO Wei;QU Jinbo(Institute of Research of Iron and Steel of Jiangsu Province, Sha steel, Zhangjiagang Jiangsu 215625, China)
出处
《上海金属》
CAS
北大核心
2020年第4期11-17,共7页
Shanghai Metals
