Q355C拉伸分层原因分析与控制
Cause Analysis and Control of Q355C Tensile Layering

通过取Q355C拉伸分层试样进行分析，发现层间的片层状MnS及其复合夹杂物是造成拉伸分层及延伸不合的直接原因，而铸坯的内部裂纹和严重中心偏析是MnS夹杂产生的根源，通过采用以提高铸机精度为核心，包括成分和轧制工艺等优化在内的系列措施，当辊缝和扇形段接弧±0.5 mm范围内的合格率达到90%以上时，延伸合格率达到100%。
Q355C tensile layering samples are analyzed, and it is found that the lamellar MnS and its composite inclusions between layers are the direct causes of tensile layering and unqualified ductility, and the internal crack and serious central segregation of slab are the basic causes of MnS inclusions. Through a series of measures focusing on improving the precision of caster and including the optimization of composition and rolling process, when the qualified rate of roll gap and caster sector connection within ±0.5 mm reaches more than 90%, the qualified rate of ductility reaches 100%.