TA1纯钛冷轧薄板冲压过程开裂原因分析

Analysis on the causes of stamping cracking of TA1 pure titanium cold rolled sheet

针对TAl纯钛冷轧薄板在冲压网状板式换热器板片的过程中发生的开裂问题，采用光学显微镜、SEM扫描电镜及EDS能谱仪等实验手段，对薄板“表面褶皱”缺陷和开裂缺陷进行了分析。结果表明，冷轧薄板“表面褶皱”部位对应的心部组织处出现有纤维状层、缝隙和孔洞等缺陷，组织出现异常的原因主要是Al和Mo元素的富集。薄板的冲压开裂部位同样发现有Al和Mo等杂质元素的富集，其开裂形式为脆性分层断裂。综合分析结果可以推断，冲压过程中的开裂发生在冷轧薄板的“表面褶皱”缺陷部位，因此坯料中Al和Mo等杂质元素的混入是导致冲压开裂的根本原因。

To the problem of cracking of stamping reticulated plate heat exchanger for TA1 pure titanium cold rolled sheet, the defects of sur- face folding and fracture were analyzed by experimental means of macroscope observation, SEM and EDS spectrometer. The results show that, there are defects such as fibrous layer, gaps and holes appearing in the heart of the sheet where presents the surface folding defects, and the main reason for abnormal organization is the enrichment of 33 and Mo elements. The enrichment of 33 and Mo elements is also found in the stamping cracking sites, and the form of cracking is interlaminar brittle fracture. It can be inferred from the comprehensive analysis results that the cracking in the process of stamping occurs in the part of the surface folding of the cold rolled sheet. Therefore, the impurity elements such as 33 and Mo in the blank are the fundamental causes of the stamping cracking.