【摘要】 铁素体球铁铸件支架在装配时发生脆性断裂失效。通过理化检测试验,对材料的化学成分、力学性能和金相组织做了较为详尽的比较。结果发现,失效件的硅含量偏南、硬度值很不均匀,冲击韧度和伸长率远低于材质要求．因而导致脆断。找出失效原因是铸造工艺不当,并提出合理化建议。更多还原

【Abstract】 The bracket of as-cast ferritic nodular iron breaks due to brittle fracture when it is assembled. The chemical composition, the mechanical properties and the microsstructure were studied though physical test and chemical analysis. The results shows that the failure parts has high silicon content and uneven hardness, the impact toughness and elongation is far below the specification of the material. The failure is caused by the improper casting technology, and some suggestions are proposed.更多还原