热轧含钛低合金高强钢板断口分层机理研究  

Mechanism research on layered fracture of hot rolling Ti-bearing HSLA plates

作　　者：董欣欣[1] 杨丽[1] 唐勤 张丽颖[1] 杨建辉 DONG Xinxin;YANG Li;TANG Qin;ZHANG Liying;YANG Jianhui(Tangshan Vocational College of Science and Technology,Tangshan 063001,Hebei,China;Shougang Jingtang United Steel Co.,Ltd,Tangshan 063205,Hebei,China)

机构地区：[1]唐山科技职业技术学院,河北唐山063001 [2]首钢京唐钢铁联合有限责任公司,河北唐山063205

出　　处：《有色金属科学与工程》2024年第1期51-57,共7页Nonferrous Metals Science and Engineering

基　　金：河北省高等学校科学技术研究项目(ZC2021255)。

摘　　要：利用光学显微镜(OM)、电子背散射衍射仪(EBSD)、透射电镜(TEM)等设备研究了含钛低合金高强钢拉伸断口分层原因。结果显示:在显微组织和晶粒尺寸正常的情况下,MnS和大颗粒Ti(C,N)夹杂物聚集是导致断口分层的根本原因。拉伸断口呈现撕裂棱+浅韧窝的准解理形貌。塑性变形过程中,Ti(C,N)破碎导致显微裂纹萌生。裂纹沿着薄膜状MnS传导,最终在MnS和基体界面形成撕裂棱。大量平行分布的MnS夹杂物共同作用,使断口产生分层现象。通过降低S、N含量能够有效减少两类夹杂物数量,消除断口分层现象,改善塑性指标。The reason for layered fracture about hot rolling Ti-bearing HSLA plate was studied by optical microscopy,electron backscattering diffraction and transmission electron microscopy.The results show that MnS and large grained Ti(C,N)complex precipitation and aggregation are the main causes when the microstructure and effective grain size are normal.The tensile fracture shows a quasi-cleavage morphology with tearing edges and shallow dimples.During plastic deformation,the microcrack initiation is attributed to the crushing of Ti(C,N).The cracks are conducted along the thin-film-like MnS,eventually forming tearing edges at Mns and matrix interface.A large number of parallel-distributed MnS inclusions act together,leading to layered fracture morphology during stretching.By reducing the content of S and N,it can effectively reduce the number of two types of inclusions,eliminate the phenomenon of fracture stratification,and improve the plastic index.

关 键 词：显微组织 拉伸断口 撕裂棱 准解理 夹杂物 

分 类 号：TG142.13[一般工业技术—材料科学与工程]