连铸TP347荒管内壁微裂纹探讨

摘要

本文对TP347H连铸坯生产的荒管内壁出现毛细裂纹缺陷进行分析和探讨，通过光学显微镜、SEM观察发现，在裂纹附近及裂纹中存在较多的含Nb脆性质点。通过提高连铸坯均热温度，减少含Nb脆性质点的析出，进而减少了连铸TP347H在热穿孔后内壁毛细裂纹。%This article analyzed and discussed the cause of the formation of capillary crack on the inner surface of the casting TP347 pierced billet. The observation under the optical microscope and SEM indicated that there were more brittle particles with Nb near the crack and in the crack. The measure for improving the casting billet soaking temperature was taken to reduce the precipitation of the brittle particles with Nb, so the capillary crack in the casting TP347 was reduced after hot piercing .