K418高温合金下引式热型连铸温度场模拟  

Simulation of Temperature Field in K418 Superalloy during Downward Ohno Continuous Casting Process

作　　者：周正华 杨帆 屠挺生[1,2,3] 蒋丹青 任忠鸣[1,2,3] ZHOU Zhenghua;YANG Fan;TU Tingsheng;JIANG Danqing;REN Zhongming(State Key Laboratory of Advanced Special Steel,Shanghai 200444,China;Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai 200444,China;School of Materials Scienceand Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]上海市钢铁冶金新技术开发应用重点实验室,上海200444 [3]上海大学材料科学与工程学院,上海200444

出　　处：《上海金属》2019年第3期89-95,共7页Shanghai Metals

基　　金：国家自然科学基金(No.51604171、No.51690162、No.U1560202);上海市科委项目(No.17JC1400602)

摘　　要：建立了镍基K418高温合金下引式热型连铸(OCC)凝固过程温度场模型,采用试验与ProCAST模拟相结合的方法修正了界面换热系数条件,使模拟结果与试验结果的最大差异不超过4%,可以较好地模拟实际凝固过程温度场。模拟结果表明:当浇注温度从1460℃升高到1540℃时,两相区宽度由15mm减小到10mm,温度梯度从33K/cm增大到40K/cm;当冷却距离由13mm增大到33mm时,两相区宽度从12mm增大到16mm,温度梯度从28K/cm降低到23K/cm;当平均拉坯速度从9mm/min增大到18mm/min时,两相区宽度从12mm增大到15mm;当温度梯度从35K/cm减小到25K/cm、拉速增大到36mm/min时,固液界面位置下移到BN铸型出口处,有拉断、漏钢的风险。K418高温合金铸锭(?10mm)合理的下引式热型连铸制备参数范围为:熔体浇注和BN铸型温度1500~1540℃,冷却距离23mm,平均拉坯速度9~18mm/min。Model of temperature field for the solidification process of the Ni-based K418 superalloy during downward ohno continuous casting(OCC)was established,and the heat transfer coefficient of interface was revised by the experiment in conjunction with the ProCAST simulation.The maximum difference between simulated results and experimental results was less than 4%,which could well simulate the temperature field in actual casting solidification.The simulation results showed that when the pouring temperature increased from 1 460℃to 1 540℃,the width of two-phase region decreased from 15 mm to 10 mm,and the temperature gradient increased from 33 K/cm to 40 K/cm;and that when the cooling distance increased from 13 mm to 33 mm,the width of two-phase region increased from 12 mm to 16 mm,and the temperature gradient decreased from 28 K/cm to 23 K/cm;and that when the mean drawing speed increased from 9 mm/min to 18 mm/min,the width of two-phase region increased from 12 mm to 15 mm;and that when the temperature gradient decreased from 35 K/cm to 25 K/cm,and the mean drawing speed reached 36 mm/min,the solid-liquid interface moved down to the outlet of the BN mold,there being the risk of steel breaking and leaking.The appropriate parameters of K418 superalloy ingot(10 mm in diameter)by the OCC were as follows:the melting temperature ranging from 1 500℃to 1 540℃,the cooling distance of 23 mm,and the mean drawing speed ranging from 9 mm/min to 18 mm/min.

关 键 词：K418高温合金 下引式热型连铸 PROCAST 温度场 数值模拟 

分 类 号：TG132.3[一般工业技术—材料科学与工程] TG249.7[金属学及工艺—合金]