拉速对紫铜水平连铸坯凝固行为及组织场影响规律研究

Simulation and Experimental Study on Solidification Behavior of Red Copper Horizontal Continuous Casting Slab at Different Drawing Speed

摘要:

水平连铸是生产铜板带坯的常用方法,探索工艺参数变化对铸坯质量的影响规律十分重要。采用数值模拟的方法分析了水平连铸拉速变化对结晶器内温度场、液穴深度、冷却速率等的影响规律,并结合工艺试验揭示了拉速变化对铸坯组织的影响机理。结果表明,随着铸坯拉速的不断提高,结晶器内的液穴深度持续增加,铸坯表面和芯部沿牵引方向的冷却速率均逐渐降低,且二者的冷却速率差值逐渐减小,当拉速为149mm/min时,二者冷却速率达到相同；随着铸坯拉速的不断提高,铸坯截面上晶粒生长方向与牵引方向的夹角逐渐增大,晶粒生长距离缩短,铸坯表面上晶粒数目增加,平均晶粒直径从1.96mm逐渐减小到1.05mm,整体组织均匀性明显提高。

Abstract:

Horizontal continuous casting is a common method to produce copper strip. It is very important to explore the influence of process parameters on the quality of the billet. The influence of drawing speed on temperature field, liquid hole depth and cooling rate in mold was analyzed by numerical simulation, and the influence mechanism of drawing speed on the structure of billet was revealed by process test. The results show that with the continuous increase of the billet drawing speed, the depth of the liquid hole in the mold continues to increase, and the cooling rates of the surface and core of the billet along the traction direction gradually decrease, and the difference between the two cooling rates gradually decreases. When the drawing speed was 149mm/min, the cooling rates of the two parts reach the same. With the continuous increase of the billet drawing speed, the angle θ between the grain growth direction and the traction direction on the section of the billet increases gradually, the grain growth distance was shortened, the number of grains on the surface of the billet increases, and the average grain diameter decreases from 1.96mm to 1.05mm, and the overall microstructure uniformity was obviously improved.