铸件壁厚对低温球墨铸铁组织和力学性能的影响  

Effect of Casting Thickness on Microstructure and Mechanical Property of Cold-resistant Nodular Iron

作　　者：龙文元[1] 谭绍武 徐建辉[2] 

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330063 [2]上海电机学院机械学院,上海201306

出　　处：《铸造技术》2015年第6期1507-1508,1509,共3页Foundry Technology

基　　金：上海市教育委员会重点科研创新项目资助(12zz199)

摘　　要：用阶梯试样研究了不同壁厚下低温球墨铸铁的组织和力学性能。研究结果表明:所有壁厚的低温球墨铸铁基体组织都是F+P,其石墨形态都是VI型+V型,球化级别都为3级,石墨大小级别都是6级。随着铸件壁厚的增大,其石墨球数和珠光体数量逐渐减少,抗拉强度、屈服强度和布氏硬度不断减小,伸长率增大;当壁厚超过75 mm时,变化规律相反。而铁素体晶粒度级别一直都随着铸件壁厚的增大而减小,冲击吸收功基本上是随着试样壁厚的增加而增大。Microstructure and mechanical properties of cold-resistant nodular iron were studied by using the step-like sample. The results show that the microstructure of ductile iron is composed of ferrite, nodular graphite and a trace of pearlite. The graphite morphology is VI＋V, the nodulizing grade has reached 3 grade, and the graphite size has reached 6grade. With the increase of the casting thickness, the count of nodular graphite and pearlite, tensile strength, yield strength and Brinell hardness decrease, and the elongation increase. When the casting thickness is more than 75 mm, the variations have an opposite tendency. The ferrite grains coarsen, and impact toughness values AKV of the specimens are improved as the casting thickness increases.

关 键 词：低温球墨铸铁 石墨球数 组织 力学性能 

分 类 号：TG255[金属学及工艺—铸造]