DWTT异常断口浅析  

Abnormal Fracture Morphology of Drop Weight Tear Test

作　　者：黄子阳[1] 李云涛[2] 张忠铧[2] 

机构地区：[1]宝山钢铁股份有限公司钢管条钢事业部,上海201900 [2]宝山钢铁股份有限公司研究院(技术中心),上海201900

出　　处：《物理测试》2014年第5期28-34,共7页Physics Examination and Testing

摘　　要：利用体视显微镜(SM)、光学显微镜(OM)和扫描电镜(SEM)对DWTT典型异常断口进行了研究,探讨了裂纹的扩展机制。结果表明,试样采用压制缺口导致撕裂面多点起裂,裂纹传播过程中发生止裂和重新起动;异常断口的形成由裂纹的止裂和重新起裂导致,同时受到锤头打击塑性变形区的影响,与产品厚度和钢级无显著相关性。Typical abnormal fracture of DWTT test was researched in this paper. Stereoscopic microscopy （SM）,optical mi-croscopy （OM） and scanning electron microscopy （SEM） were used to evaluate the fracture and microstructure characteris-tics. Crack propagation and fracture mechanism were researched simultaneously. Results show that abnormal fracture be-come the main fracture morphology with the improvement of steel cleanliness and strength. It easily leads to tear withmulti-point crack initiation tested with pressed-notch specimens in DWTT. Crack arrest and re-crack initiation of crackpropagation in the tearing process were also the reasons that lead to the formation of abnormal fracture.

关 键 词：DWTT 异常断口 断裂韧性 剪切面积率 

分 类 号：O346.1[理学—固体力学]