VAR法钒合金的铸态组织特征  

As-Cast Microstructure Character of Vanadium Alloys Made by VAR

作　　者：李鱼飞[1] 罗超[1] 王志钢[1] 黄火根[1] 贾建平[1] 唐县娥[1] 蒋春丽[1] 

机构地区：[1]中国工程物理研究院表面物理与化学国家重点实验室,四川绵阳621907

出　　处：《稀有金属材料与工程》2008年第12期2152-2156,共5页Rare Metal Materials and Engineering

摘　　要：利用VAR(vacuum arc remelting of consumable electrode,真空自耗电极电弧重熔)法制备了V-4Cr-4Ti(ω/%,下同)钒合金,并采用XRD、OM、SEM和TEM对铸态组织结构进行了分析。结果表明:铸锭杂质C、N、O含量高,Ti、Cr都有一定的烧损,合金实测成分为V-3.7Cr-3.6Ti。铸锭内部含有许多的微小气孔。合金具有明显的3个晶区:激冷层的晶粒大小不均,平均晶粒尺寸500μm;等轴晶区晶粒大小分布也不均匀,但平均晶粒尺寸较激冷区的更大;柱状晶区晶粒明显拉长,长度可达2mm。固溶体晶格常数a=0.3021nm。合金为多相结构,第二相有两种类型:1)在晶内呈"盘状"形貌,其厚度100～150nm,其余两维尺寸达到1～2μm,在晶界处呈连续网状分布。该析出相是富Ti型的Ti-(CON);2)少量的粒径达1～2μm的"球形"析出相,推测也是Ti-(CON)。Vanadium alloys was fabricated by VAR（vacuum arc remelting of consumable electrode） and its cast state microstructure was analyzed by XRD, OM, SEM and TEM. Results show that the impurities concentration of C, N, O is very high, and Ti and Cr both having melting loss at some degree. The real composition of ingot is V-3.7Cr-3.6Ti, There are a lot of pores in the ingot. There are three kinds of grain regions in the ingot obviously, and it＇s the typically solidification structure. The grain size in the chili regions is not uniform, and average grain size is about 500μm. the grain sizes in the equiaxial region is also not uniform, while the average size is larger than chill region. The columnar region grain size is about 2 mm and the grains had been elongated obviously. The lattice parameter of the solid solution is 0.3021 nm. There are two kinds of the second phases in the alloy： 1） the precipitation, which is the Ti-rieh type Ti-（CON）, in the grains having the shape of ＂plate＂ with thickness up to 100 nm and the other two dimensions up to 1-2 μm and forming the continuous films at grain boundaries; 2） the rare ＂globular＂ shape precipitation with 1 -2μm in diameter, which also presumed to be the Ti-（CON）.

关 键 词：钒合金 化学成分 铸态组织 第二相 

分 类 号：TG146.413[一般工业技术—材料科学与工程] TG113.12[金属学及工艺—金属材料]