1.2738预硬化模块成品模具皮纹处理后异常带状问题分析

Analysis on the Abnormal Strip Problem After the Finished Mold Skin Line of 1.2738 Prehardened Module

针对1.2738模块成品模具皮纹处理后表面存在异常带状问题进行分析,综合运用光学显微镜、电子探针及显微硬度计对异常带状处进行组织、成分、硬度等进行研究。结果表明,1.2738成品模具皮纹处理后,表面存在的白色条带状是由于模块预硬化后存在组织不均现象导致。由于模块内部存在合金元素微观偏析现象,导致模块预硬化处理后内部存在组织不均匀现象。基体组织为均匀的下贝氏体组织,元素偏析区存在粗大的针状异常组织,为中高碳下贝氏体+粒状贝氏体组织复相组织。

The abnormal strip problem after the finished mold skin line of 1.2738 prehardened module was analyzed, researched on microstructure, composition, hardness at the abnormal strip by OM, EP and micro hardness tester synthetically. The result show that, the withe strip on the surface after skin line of 1.2738 mold was caused by not uniform mierostrueture after prehardening of the module. The internal structure was not uniform after prehardening of the module because of the existence of the alloy element segregation in the module. The substrate structure was uniform lower bainite, and presented large needle structure in element segregation are, that was composite structure of middle and high carbon lower bainite ＋ granular bainite.