钢中非金属夹杂物对显微组织的影响

使用金相法对碳素结构钢Q235B钢板的拉伸试样非正常断口进行分析，研究了钢中夹杂物类型和形态以及钢的显微组织。结果表明，Q235B钢板拉伸试样非正常断口及附近部位夹杂物严重，且存在粗大的带状组织，带状铁素体中有明显的非金属夹杂物。粗大带状组织的形成原因是由于铁素体以非金属夹杂物为结晶核心并沿着非金属夹杂物的变形方向生长而形成的。

Effect of Nonmetallic Inclusions in Steel on Banded Structure

The abnormal fracture of tensile specimen from carbon structural steel plate Q235B has been analyzed by metallographic microscope. Along with the type and shape of the inclusions,the microstructure of the steel has been studied. The results show that the inclusion concentration in the abnormal fracture and neighboring area on Q235B steel plate is high and coarse banded structure exists. Obvious nonmetallic inclusions are existing in the banded ferrite structure. The cause of the coarse banded structure formation is that the ferrite crystallization is based on the nonmetallic inclusions as core and the ferrite structure grows in the direction of nonmetallic inclusion deformation.