提高特厚规格Q275D热轧H型钢冲击性能的研究

针对莱钢特厚规格Q275D热轧H型钢纵向低温冲击性能不合格的问题,采用金相显微镜和扫描电镜对其显微组织进行了分析,结果表明:混晶组织是造成低温冲击性能不合格的主要原因。根据莱钢现有设备,通过优化成分设计和控制轧制工艺参数,使得此规格H型钢晶粒尺寸细小均匀,-20℃纵向V型冲击功平均值大于160 J,满足相应标准要求。

Study on improvement of impact property of extra thick Q275D hotrolled H-beam steel

Aiming at the problem that the low temperature longitudinal impact property of extra thick Q275D hot rolled H-beam steel produced by Laiwu Steel was not up to standard, its microstructure was analyzed by metallographic microscope and scanning electron microscope.The results showed that the mixed grain structure was the main cause of the unqualified low temperature impact property.Based on the equipment conditions of Laiwu Steel, by optimizing chemical design and controlling rolling process parameters, the grain size was fine and uniform, and the longitudinal average impact value at-20 ℃ was greater than 160 J.The longitudinal impact property met the requirements of the relevant standard.