氧化镧对履带堆焊层合金微观组织与耐磨性的影响  

Influence of La_2O_3 on Microstructure and Wear Resistance of Crawler Belt Hardfacing Alloy Surface

作　　者：刘勇[1] 王亚军[2] 杨育林[2] 杨庆祥[2] 

机构地区：[1]中国兵器工业集团内蒙古第一机械集团有限公司,内蒙古包头014030 [2]燕山大学极端条件下机械结构与科学国防重点学科实验室,河北秦皇岛066004

出　　处：《表面技术》2017年第3期113-118,共6页Surface Technology

基　　金：国家自然科学基金(51471148)~~

摘　　要：目的研制一种新型含氧化镧(La_2O_3)堆焊装甲车履带用药芯焊丝,通过细化堆焊层合金的微观组织,提高堆焊层合金的耐磨性。方法采用堆焊的方法制作堆焊层合金,采用金相显微镜观察了其表面显微组织,并测定了其表面洛氏硬度和耐磨性。结果堆焊层合金微观组织由粒状贝氏体、马氏体和残余奥氏体组成。未加氧化镧的堆焊层合金初生奥氏体晶粒粗大,其平均尺寸在42μm,耐磨性为6000 min/g;当药芯焊丝中加入质量分数为2.5%的氧化镧之后,堆焊层合金的奥氏体晶粒尺寸最小,其平均尺寸为36μm,耐磨性为12 300 min/g。铝酸镧(LaAlO_3)的(001)面与奥氏体(100)面之间的二维错配度为3.81%。结论铝酸镧作为γ-Fe的异质形核核心最有效,说明堆焊层合金中铝酸镧可以使初生奥氏体的晶粒尺寸得到细化,从而改善了履带堆焊层合金的耐磨性。The work aims to develop a novel flux-cored wire with La2O3 for hardfacing armored car crawler belt and improve wear resistance of the hardfacing alloy layer by refining the microstructure.The hardfacing alloy layers were deposited by means of automatic open arc surfacing welding method.The microstructure was observed by using an optical microscopy.Meanwhile,Rockwell hardness and wear resistance of the hardfacing alloy surface were measured.The microstructure of the hardfacing alloy contained bainite,martensite and residual austenite.The average size of primary austenite was about 42 μm and mass loss of the La2O3-free alloy 6000 min/g.With La2O3 added,the average size of primary austenite was about 36 μm and mass loss 12300 min/g.The two-dimensional lattice misfit between the（001） face of LaAlO3 and（100） face of austenite was 3.81%.With La2O3,LaAlO3 as most effective γ-Fe heterogeneous nuclei,the primary austenite is refined and thereby the wear resistance of the hardfacing alloy layer can be improved as well.

关 键 词：履带 堆焊技术 氧化镧 微观组织 耐磨性 

分 类 号：TG422.3[金属学及工艺—焊接]