球墨铸铁管卡脆断原因分析  

Analysis on Brittle Fracture Causes of Nodular Cast Iron Pipe Clamp

作　　者：吕柏林[1] 吕品[1] 苏辉[1] 吴敏[1] 

机构地区：[1]辽宁石油化工大学机械工程学院,辽宁抚顺113001

出　　处：《热加工工艺》2017年第11期252-256,260,共6页Hot Working Technology

摘　　要：从宏观断口形貌、金相显微组织、化学成分等方面分析了球墨铸铁管卡脆断的原因。脆断管卡断口存在大面积白口组织是其脆断的直接原因。金相分析表明,珠光体含量和游离渗碳体含量越多,管卡的脆性越严重。本文进一步分析了各种化学元素对铸态球墨铸铁组织的影响,结合工艺过程的仔细调查,确定Cr、Mn含量高是球墨铸铁管卡脆断的主要原因,并给出稳定球墨铸铁管卡质量的措施。From the aspects of macroscopic fracture morphology, optical microstructure, chemical composition, the brittle fracture causes of nodular cast iron pipe clamp were analyzed. The results show that a large area of chilling microstructure in the brittle broken fracture of pipe clamp is the direct cause of brittle fracture. The microstructure analysis shows that the more the content ofpearlite and free cementite is, the more serious the brittleness of pipe clamp is. By further analysis of the effects of various chemical elements on nodular cast iron＇s microstructure, combined with careful investigation of the production process, it is concluded that high Cr and Mn contents are the main reasons of nodular cast iron pipe clamp＇s brittle fracture and the measures to ensure the quality stability of nodular cast iron pipe clamp are given.

关 键 词：球墨铸铁 脆性断裂 管卡 显微组织 白口组织 

分 类 号：TG255[金属学及工艺—铸造] TG250.6