热疲劳作用下球墨铸铁组织变化规律  

Microstructure change of nodular cast iron under thermal fatigue

作　　者：那顺桑[1] 何惠岚 田波 宫进华[1] 赵玲燕[1] 张国涛[1] 

机构地区：[1]河北联合大学冶金与能源学院,河北唐山063009 [2]河北唐山金石超硬材料有限公司,河北唐山062004

出　　处：《金属热处理》2013年第6期43-46,共4页Heat Treatment of Metals

摘　　要：按球化率优化了球墨铸铁的化学成分,分析了热疲劳作用下球墨铸铁的组织变化。结果表明,球墨铸铁最佳热处理工艺为890℃淬火+400℃回火,可获得最佳的强韧性配比。890℃淬火次数对石墨级别基本没有影响。初次时,基体组织以马氏体为主;随淬火次数增加铁素体数量逐步增加,约25次左右铁素体量最多;随后铁素体数量减少,直至50次时组织几乎都是马氏体+石墨。Chemical composition of nodular cast iron was optimized based on spheroidizing rate, and microstructure change of nodular cast iron was analysed under thermal fatigue. The results show that the optimum heat treatment process is quenching at 890 ℃ and tempering at 400 ℃ that can obtain the best combination of the strength and toughness. At 890 ℃quenching, the number of quenching times almost has no effect on the graphite grades. Matrix structure is martensite at the first time quenching. With number of quenching times increasing, ferrite gradually increases which reachs to the maximum when quenched 25 times. After that ferrite began to decrease, and the microstructure is ahnost fully become martensite ＋ graphite until quenching reaches 50 times.

关 键 词：热疲劳 球墨铸铁 组织变化 

分 类 号：TG143.5[一般工业技术—材料科学与工程]