超大规格2024铝合金扁锭开裂行为研究

Research on cracking behavior of ultra-large 2024 aluminum alloy flat ingots

随着航空航天大型结构件尺寸的增大,高强铝合金铸锭的尺寸也要增大,铸锭成型难度也随之增大。通过铸造过程数值模拟研究了铸造速度和刮水器位置对500 mm×2300 mm和600 mm×2500 mm规格2024铝合金扁铸锭温度场及应力场的影响规律。结果表明,铸造速度对液穴深度影响最大,提升铸造速度能够大幅降低铸锭内应力,但是大幅增加了液穴深度,不利于减轻铸锭疏松和热裂;提升刮水器位置可以大幅降低铸锭的应力。提出了降低铸造速度的同时提升刮水器位置的工艺优化方向,该工艺可以制备超大规格2024铝合金扁铸锭。

The size of high-strength aluminum alloy flat ingots increases as aerospace structural components become larger,thus the difficulty of ingot casting also increases.The influence of casting speed and wiper position on the temperature and stress fields of 500 mm×2300 mm and 600 mm×2500 mm 2024 aluminum alloy flat ingots was studied through numerical simulation of the casting process.The results indicate that casting speed has the greatest impact on the melt sump depth,and increasing casting speed can greatly reduce internal stress.However,a substantial increase in the depth of the sump is not conductive to reducing the porosity and hot cracking of the ingot.Raising wiper position can effectively reduce internal stress.This process can be optimized by reducing casting speed and raising wiper position.The industrial trial production with this technology can be used for preparing oversized 2024 aluminum alloy flat ingots.