【摘要】 以屈服强度450 MPa级船板钢为研究对象，采用金相显微镜、扫描电镜、电子探针及硬度计等检测分析手段，研究高强船板钢断口分层的形成原因及其影响因素。研究结果表明：铸坯中心出现明显的组织偏析；热轧船板回火后心部的珠光体带宽度达76.81μm,带状组织处Mn、Si、Cr、Ni、Cu均存在明显偏析；断口形貌观察发现裂纹沿珠光体带状组织穿晶或沿晶扩展，裂纹扩展深度约3 mm。铸坯存在严重中心偏析是造成断口分层的主要原因。更多还原

【Abstract】 Taking 450 MPa yield strength grade hull plate as research object, the paper studies the formation causes of high strength hull plate fracture lamination and their influencing factors by means of metallographic microscope, scanning electron microscope, electron probe and hardness meter.The results show that apparant microstructure segregation at the slab center, the width of pearlite band at the center of as-rolled plate after normalizing is up to 76.81 μm, obvious segregation of Mn, Si, Cr, Ni, Cu exist in the banded microstructure, the cracks penetrate the grain boundary along pearlite banded microstructure or propagate along grain boundary, the depth of crack propagation is around 3 mm.Severe central segregation existed in slab is the major cause of the fracture lamination.更多还原