新型抽锭电渣重熔冷却过程的多物理场耦合模拟

MULTI-PHYSICAL FIELD COUPLING SIMULATION OF THE COOLING PROCESS OF NEWLY-DEVELOPED PUMPING ESR

针对新型抽锭电渣重熔工艺，基于金属．热一力多物理场耦合理论框架，建立了抽锭冷却过程的数值分析模型，讨论了尺寸为φ120mm电渣锭在冷却过程中的温度场、组织场和应力场的演变规律。研究表明：电渣锭在冷却过程中，心部和中部冷却速度最快可达到3～4℃／s，温度梯度保持在10～12℃／mm之间，表面温度变化剧烈且出现返温现象，最大冷却速度可达14．5℃／s；在抽锭过程中，电渣锭表面、中部和心部的应力整体上呈现上升趋势，电渣锭最大应力不超过1200MPa。模拟结果和实测值吻合，表明本文建立的数值分析模型能较好地反映新型抽锭电渣重熔的冷却过程，可用于指导生产实际。

By taking a newly-developed pumping ESR process as the research object, a numerical model based on the metallo-thermo-mechanical coupled theory was established to simulate the cooling process of pumping electroslag ingot, to explore the evolution rule of temperature, microstructure and stress in the electroslag ingot with a diameter of 6120 mm during the cooling process. The results showed that, during the cooling process, the maximum cooling rate at the center and middle of electroslag ingot could achieve almost 3 - 4℃/s and its temperature gradient maintained up to 10 - 12 ℃/mm, while the temperature at the surface of electroslag ingot experienced a dramatic change and caused a reverse phenomenon of temperature, and its maximum cooling rates was about 14.5℃/s. The stress at the center, middle and surface of electroslag ingot presented an increasing trend during the pumping process and its maximum effective stress was no more than 1 200 MPa. The predicted results were coincidence well with the experimental data, which indicated that the numerical model established in the present study could effectively reproduce the cooling behavior of newly-developed pumping ESR process and it could be used to guide the production.