大型锻造用钢锭凝固疏松缺陷的数值模拟

利用有限元软件ProCast对大型锻造用钢锭的非稳态浇注过程和凝固过程进行了数值模拟。对两种不同的浇注工艺方案,通过温度场和固相场,分析了采用双包浇注时不同浇注温度对凝固过程和疏松形成规律的影响。结果发现：后浇包的浇注温度低,加快了钢锭上部的凝固,降低了冒口的补缩能力,导致疏松缺陷偏下,数值模拟与实验结果基本吻合。而方案2模拟的疏松缺陷向冒口处上移92mm,更有利于钢锭锻造过程中对疏松缺陷的消除。

Numerical Simulation of Porosity Defects in Large Forging Steel Ingots

A 234-ton large forging steel ingot has been simulated by using professional numerical software ProCast.During the two schemes of different casting process,the influences of pouring temperatures on casting processes and porosity defects in two-ladle casting process were analyzed by using the temperature field and solid fraction.The simulating and experimental results show that:When the pouring temperature of the second ladle is lower,the solidification of the upper part of the steel ingot is faster so that the ability of riser feeding can be reduced and the locations of the porosity defects can be decreased in the steel ingot.The simulation results are identical to the experimental results.But the porosity defects in the second scheme move upward to the riser line about 92 mm due to the same pouring temperature in the second scheme,which is beneficial to eliminate the porosity defects in the ingot during forging processes.