La_2O_3添加量对Fe-3Mo-3Cr-0.6V-0.5Mn-0.8C合金组织与力学性能的影响  

Effects of La_2O_3 content on microstructure and mechanical property of Fe-3Mo-3Cr-0.6V-0.5Mn-0.8C alloy

作　　者：徐杰 刘如铁[1] 熊翔[1] 丁焕 陈洁[1] 廖宁 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2017年第6期808-814,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点研发计划资助项目(2016YFB0700302)

摘　　要：以羰基铁粉、钼铁粉、铬铁粉、钒铁粉、锰铁粉、石墨和稀土La_2O_3为原料,采用真空烧结法制备La_2O_3改性Fe-3Mo-3Cr-0.6V-0.5Mn-0.8C合金,研究La_2O_3添加量(0.1%~0.7%,质量分数)对合金密度、硬度、组织结构以及力学性能的影响。结果表明,随La_2O_3添加量增加,合金的晶粒度明显减小,密度、硬度与抗弯强度都出现"双峰值效应"。当合金中加入0.1%La_2O_3时,合金具有最高的密度6.79 g/cm3和较高的硬度(HB)240,抗弯强度达到最大值2 300 MPa,比不含La_2O_3的合金抗弯强度提高近12%,弯曲断裂形式由脆性断裂转变为穿晶-沿晶断裂的复合断裂形式。The lanthana oxide modified Fe-3Mo-3Cr-0.6V-0.5Mn-0.8C alloy were prepared by vacuum sintering using carbonyl iron, molybdenum iron, chromium iron, vanadium iron, and manganese iron powders, graphite and rare earth La2O3 as raw materials. The effects of La2O3 content （0.1%~0.7%, mass fraction） on the density, hardness, microstructure and mechanical property of the alloys were studied. The results show that the grain size decreases obviously, density, hardness and bend strength all show a “bimodal peak effect” with increasing La2O3 content. When La2O3 content is 0.1%, the alloy has the highest density of 6.79 g/cm3, higher hardness （HB） of 240, and the maximum bending strength of 2300MPa which is 12% higher than that of alloy without La2O3. The bend fracture mode changes from brittle fracture to composite fracture mode of transgranular and intergranular fracture.

关 键 词：烧结合金钢 稀土 氧化镧 力学性能 双峰值效应 穿晶-沿晶断裂 

分 类 号：TF125[冶金工程—粉末冶金]