低合金高强钢拉伸断口分层的原因分析  

Cause Analysis of Delamination in Tensile Fracture of Low Alloy High Strength Steel

作　　者：陈萌 孙乾 白莹 刘亚儒 徐延岭 吴群 CHEN Meng;SUN Qian;BAI Ying;LIU Yaru;XU Yaning;WU Qun(Nanjing Iron and Steel Co.,Ltd.,Nanjing 210035,China;Shandong Iron and Steel Co.,Ltd.Laiwu Branch,Jinan 271104,China;Shandong Jinding Group Co.,Ltd.,Jinan 271104,China)

机构地区：[1]南京钢铁股份有限公司,江苏南京210035 [2]山东钢铁股份有限公司莱芜分公司,山东济南271104 [3]山东金鼎集团有限公司,山东济南271104

出　　处：《山东冶金》2024年第1期39-41,共3页Shandong Metallurgy

摘　　要：针对420 MPa级别低合金钢板室温横向拉伸断口出现分层现象,通过断口形貌、非金属夹杂物及金相组织观察以及扫描电镜、能谱检验等分析技术手段,对其宏观形貌、微观组织等综合分析,并对断口分层的原因及影响因素进行探讨。结果表明,试样存在心部偏析及MnS夹杂物,割裂基体,形成应力集中区域是该试样拉伸断口分层的主要原因。通过提高钢水的纯净度,严控钢液中的硫、磷等有害元素含量;配合连铸低过热度浇注工艺,合理控制拉坯速度,优化控轧控冷工艺,可有效减少该类缺陷发生概率。Aiming at the lamination phenomenon of transverse tensile fracture of grade 420MPa low alloys steel plate at room temperature,the macroscopic morphology and microstructure were analyzed by the observation of fracture morphology,non-metallic inclusions and metallographic structure,scanning electron microscope and energy spectrum test,and the causes and influencing factors of the lamination were discussed.The results show that the existence of core segregation and MnS inclusions in the specimen is the main reason for the delamination of tensile fracture.By improving the purity of molten steel,the contents of sulfur,phosphorus and other harmful elements in molten steel are strictly controlled.In combination with the low superheat casting process of continuous casting,reasonable control of casting speed and optimization of controlled rolling and cooling process can effectively reduce the probability of such defects.

关 键 词：低合金钢板 拉伸断口 分层 偏析 过热度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]