A process model for on-line quenching of aluminium extrusions
A process model for on-line quenching of aluminium extrusions
复制标题
铝型材在线淬火的工艺模型
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
S. Tjo̸tta
中科院分区：
文献类型：
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作者：
N. Järvstråt;S. Tjo̸tta
提出了一个完整的铝型材冷却过程模型。它能够预测热引起的变形和可能的强度降低。该模型由三部分组成：热部分、冶金部分和机械部分。热部分包括热传递和热传导模型，并生成作为其他两个部分输入所需的温度历史。冶金部分包括冷却过程中非硬化粒子析出的运动学模型，并预测随后时效后的强度。最后，机械部分包括通常的兼容性和一致性方程，以及统一的材料模型，该模型对于高温下与速率相关的材料行为和在低温下几乎与速率无关的行为都非常准确。进行了水冷实验，并利用该过程模型进行了有限元模拟。水淬火的换热系数对几何形状和其他冷却条件极为敏感。此外，冷却特性和材料模型是预测变形的同等重要的因素。
A complete process model for the cooling of aluminium extrusions is presented. It is capable of predicting both thermally induced distortions and possible strength reductions. The model consists of three parts: a thermal part, a metallurgical part, and a mechanical part. The thermal part includes heat-transfer and heat-conduction models and generates the temperature history needed as input to the other two parts. The metallurgical part consists of a kinematic model for the precipitation of nonhardening particles during cooling, and it predicts the resulting strength after subsequent aging. Finally, the mechanical part comprises the usual compatibility and consistency equations, as well as a unified material model that is very accurate both for rate-dependent material behavior at high temperatures and for the virtually rate-independent behavior at low temperatures. Water-cooling experiments have been performed, and finite element simulations were executed using the process model. The heat-transfer coefficient for water quenching is shown to be extremely sensitive to geometry and other cooling conditions. In addition, the cooling characteristics and the material model are factors of equal importance in the prediction of distortions.