摘要
采用不同过热度浇注了连铸坯,轧制了70 mm的Q345GJZ15厚钢板。为研究连铸过热度对厚钢板抗层状撕裂性能的影响,通过拉伸试验机对钢板Z向拉伸试样进行了检测,应用金相显微镜、扫描电镜和能谱分析仪对拉伸断口形貌、组织和成分进行了分析。结果表明:在一定拉速下,过热度高,连铸坯中心偏析严重,等轴晶比例少,钢板抗层状撕裂性能差。连铸坯中心偏析经轧制不能完全消除,含Nb、Ti的碳化物和MnS等夹杂在中心聚集,并形成贝氏体和马氏体组织,是造成厚钢板Z向拉伸脆断的主要原因。
Continuous casting slabs were casted with two superheating. Heavy plates of 70 mm in thickness were rolled. Z-direction tensile test of plate was carried out on a tensile testing machine. Microstructure, morphology and composition were analyzed to find out the relationship between slab quality and lamellar tearing resistance by optical mi- croscopy, scanning electron microscopy and energy dispersive spectrometry. Results show that central segregation in- creases and the amount of equiaxed grains decrease in slab with high superheating. Poor lamellar tearing resistance of plate is obtained because the defects can be inherited after hot rolling. Central segregation, inclusions and the for- mation of bainite and martensite are the reasons of brittle fracture during Z-direction tensile test.
出处
《物理测试》
CAS
2013年第6期41-45,共5页
Physics Examination and Testing
关键词
抗层状撕裂
过热度
连铸坯
厚钢板
中心偏析
lamellar tearing resistance
superheating
continuous casting slab
heavy plate
central segregation
