摘要
针对φ30 mm无氧铜杆坯,建立了温度场计算理论模型,采用CA-FE法分析了上引连铸工艺参数对无氧铜杆坯铸态组织的影响。结果表明,当冷却强度和铸造温度不变时,随着杆坯牵引速度提高,结晶器内部铜液凝固位置向出口方向移动,液穴深度增加,导致杆坯出口温度不断升高,并且牵引速度与出口温度满足二次函数关系;当冷却强度和牵引速度不变时,随着铸造温度升高,结晶器内铜液面高度增加,凝固位置上移,而液穴深度无明显变化。CA-FE铸坯组织模拟发现,以牵引速度为变量时,较低的牵引速度使得凝固组织几乎全部为粗大的柱状晶且数量较少,柱状晶沿牵引方向生长,随着牵引速度增大,表层出现了细晶区,柱状晶变得细长且数量增加,柱状晶与牵引方向的夹角减小,当牵引速度增大到5.5 mm/s时,芯部开始出现少量等轴晶;以铸造温度为变量时,铸造温度升高使得柱状晶数量、尺寸和生长方向无明显变化,而芯部等轴晶数量减少,逐渐被柱状晶取代。
The theoretical model of temperature field calculation forϕ30 mm oxygen-free copper billet was established,and influence of the upward continuous casting parameters on the microstructure of as-cast oxygen-free copper billet was analyzed by CA-FE method.The results indicate that with the constant cooling intensity and temperature,the solidification position of liquid copper inside the mold moves towards the outlet and the cavitation depth is increased with the continuous increase of the drawing speed,leading to the continuous increase of the outlet temperature,while the relation between the drawing speed and outlet temperature meets the quadratic function.When the cooling intensity and drawing speed are constant,the level height of liquid copper in the mold is increased and solidification position moves upward with the increase of casting temperature,while the cavitation depth has little change.The CA-FE simulation results reveal that solidification structure almost consist of a quantity number of coarse columnar crystals under low traction speed with drawing speed as variable,and the columnar grains grow along the drawing direction.With increasing in drawing speed,a fine crystal zone appears on the surface,and the columnar crystals become slender with increasing in amounts,while the angle between columnar crystals and the traction direction is decreased.With the drawing speed increasing to 5.5 mm/s,a small amount of equiaxed crystals appear in the core.With the increase of casting temperature,the quantities,size and growth direction of columnar crystals remain stable with casting temperature as variable,while equiaxed crystals in the core are decreased,which are gradually replaced by columnar crystals.
作者
徐勇
郑莲宝
王松伟
梅伟
聂艳春
Xu Yong;Zheng Lianbao;Wang Songwei;Mei Wei;Nie Yanchun(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016;College of Metallurgy and Energy,North China University of Science and Technology,Tangshan O63210;JCC Copper Strip Co.,Lid.,Nanchang 330096)
出处
《特种铸造及有色合金》
CAS
北大核心
2024年第3期364-371,共8页
Special Casting & Nonferrous Alloys
基金
中国科学院青年创新促进会专项基金资助项目(2019195)。
关键词
无氧铜
上引连铸
CA-FE法
牵引速度
凝固
Oxygen-free Copper
Upward Continuous Casting
CA-FE Method
Drawing Speed
Solidification
