热处理工艺对RuT300蠕墨铸铁力学性能与导热性能的影响  

Effect of heat treatment on mechanical properties and thermal conductivity of RuT300 vermicular graphite cast iron

作　　者：武岳[1] 李建平[1] 张延京[1] 杨忠[1] 陶栋[1] 杨通[1] WU Yue LI Jian-ping ZHANG Yan-jing YANG Zhong TAO Dong YANG Tong(School of Materials and Chemical Engineering, Xi＇an Technological University, Xi＇an 710021, China)

机构地区：[1]西安工业大学材料与化工学院,陕西西安710021

出　　处：《材料热处理学报》2017年第2期143-151,共9页Transactions of Materials and Heat Treatment

基　　金：国家"973"项目(2012CB619606-2)

摘　　要：对Ru T300蠕墨铸铁合金进行了900℃、950℃、1000℃正火处理,并对1000℃加热处理的试样进行不同冷却处理(炉冷,空冷,风冷和喷水雾冷)。与铸态合金相比,热处理后的Ru T300蠕墨铸铁合金中珠光体含量随奥氏体化加热温度提高而增高。并且随着奥氏体化后冷却速度的增大,珠光体含量逐渐增高,最高可达77.6%,较铸态组织增加了50%,珠光体层片间距逐渐减小,最小间距约为0.2μm,较铸态珠光体减小了0.4μm,抗拉强度和布氏硬度分别提高了25%和73%,但导热性能下降20%~30%。热处理后蠕虫状石墨数量和尺寸有所减小(1000℃),石墨与基体结合部位会出现开裂、脱粘现象,导致传热受阻,导热率下降。Vermicular graphite cast iron RUT 300 was normalized at temperature of 900 ℃ , 950 ℃ and 1000 ℃ , respectively, and some of the specimens heated at the temperature of 1000 ℃ were cooled by different methods, which were furnace cooling, air cooling, forced air cooling and spray cooling. It is found that in comparison with that of the as cast state, the pearlite content in the normalizing heat- treated alloy increases significantly. With the cooling rate increasing, the pearlite content increases and the highest content of 77.6% is obtained. However, the pearlite interlamellar spacing is reduced and the minimum value of 0.2 μm is observed. Compared with the as- cast microstructure, the pearlite content increases by 50% and the pearlite interlamellar spacing is reduced form 0. 6 μm to 0. 2 μm, meanwhile, the tensile strength and hardness of the heat treated alloy is enhanced by 25% and 73% , respectively, however, the thermal conductivity decreases by 20% to 30% . Cracking and debonding between graphite and matrix in the heat treated alloy are found and the quantity and size of the vermicular graphite in the alloy treated at 1000 ℃ are reduced, which resulted in the decrease of thermal conductivity.

关 键 词：RuT300蠕墨铸铁 正火 力学性能 导热性能 

分 类 号：TG143.49[一般工业技术—材料科学与工程]