船用钛合金焊接接头精细组织表征  

Microstructure of TIG welded joint of marine titanium alloy

作　　者：高福洋[1] 廖志谦[1] 熊进辉[1] 李士凯[1] 

机构地区：[1]中国船舶重工集团公司第七二五研究所,洛阳471000

出　　处：《焊接学报》2016年第4期124-128,134,共5页Transactions of The China Welding Institution

摘　　要：对12 mm厚Ti6321进行TIG焊,采用OM,TEM等方法对焊接接头显微组织进行了分析,划分了焊接接头的区域,并讨论了各区的精细组织变化规律.结果表明,焊缝从表面到中心晶粒逐渐由柱状晶过渡为等轴晶,随着高温停留时间的延长和温度梯度的降低,晶内α相有粗大的等轴化趋势,位错密度不断升高.热影响区根据焊接热循环所处最高温度的不同划分为过渡区、细晶区和粗晶区.过渡区为等轴α、棒状α和残留β,细晶区为棒状α和残留β,粗晶区为针状α和残留β,随着高温停留时间的降低,晶内α较为细小,位错密度不断降低.The welded joint microstructure of 12 mm thick Ti6321,welded by TIG,has been analyzed by using OM and TEM,and the rule of the microstructure of different joint area has been researched.The results show that the microstructure of seam is columnar grains,which contain course α.The coarse αis formed because the effect of the latter weld seam on prior weld seam.The acicular α' is formed for a short residence time for latter weld seam at high temperature;HAZ comprised transition zone,fine grain zone and coarse grain zone,the grains in HAZ are equiaxed but with different sizes and forms.Transition zone is consisted of equiaxed a,rod α' and remained β grain.The grain zone is consisted of rod α' and remained β grain;coarse grain zone is consisted of acicular α' and remained β grain.

关 键 词：钛合金 TIG焊 精细组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG401[金属学及工艺—金属材料]