高强汽车大梁钢纵剪断裂分析  

Analysis of longitudinal shear fracture of high strength automobile girder steel

作　　者：郭晓雨 任树洋 汪云辉[1] 陈彤 Guo Xiaoyu;Ren Shuyang;Wang Yunhui;Chen Tong(Tangshan Iron&Steel Group Co.,Ltd.,Tangshan 063000,Hebei,China)

机构地区：[1]唐山钢铁集团有限责任公司,河北唐山063000

出　　处：《特钢技术》2025年第1期43-47,共5页Special Steel Technology

摘　　要：高强大梁钢常常因强度高在加工过程中出现开裂,给下游客户造成一定的人力、物力损失,因此本文利用光学显微镜(OM)、扫描电镜(SEM)对700MPa级别高强汽车大梁钢在纵剪时出现断裂现象进行原因分析。结果表明:在同一视场下TiN析出物数量多,尺寸偏大,产生了裂纹质点,加上大尺寸夹杂物偏多,增大了开裂风险;头部卷取温度CT偏高,波动超过50℃以上,加剧了铁素体粗化,导致大梁钢脆性增大,韧性下降,最终导致大梁钢纵剪断裂。针对以上开裂原因制定了相应措施,解决了大梁钢纵剪断裂问题,提高了大梁钢质量水平。High-strength beam steel often experiences cracking during processing due to its high strength,causing certain human and material losses for downstream customers.Therefore,this study uses optical microscopy(OM)and scanning electron microscopy(SEM)to analyze the reasons for the fracture phenomenon of 700 MPa high-strength automotive beam steel during longitudinal shear.The results show that under the same field of view,TiN precipitates have a large quantity and larger size,resulting in crack particles.In addition,there are more largesized inclusions,which increases the risk of cracking.Furthermore,the coiling temperature(CT)at the head is excessively high,with fluctuations exceeding 50℃,which exacerbates the coarsening of ferrite,leading to increased brttleness and decreased toughness of the beam steel,ultimately resulting in longitudinal shear fracture of the beam steel.Corresponding measures have been formulated to address the causes of cracking mentioned above,solving the problem of longitudinal shear fracture in beam steel and improving the quality level of beam steel.

关 键 词：大梁钢 纵剪 断裂 夹杂物 

分 类 号：TG111.7[金属学及工艺—物理冶金]