Abstract

The article describes the development and pilot-industrial testing of the technology for producing bars from aluminum alloy D16T obtained by radial-shear rolling (RSR) from continuously cast billets (CCB) with a diameter of 72 mm in several passes. The actual dimensions of the rolled bars were within ±0.16 mm for all bar diameters, which is significantly less than the diameter tolerance stipulated by the requirements of GOST 21488–97. According to the results of tensile tests, the values of ultimate strength, conventional yield strength, relative elongation, and relative reduction were determined. The requirements of the regulatory documents for the ultimate strength and relative elongation for the D16T alloy are satisfied with a total elongation ratio of more than 4.2. In terms of plastic properties, the obtained bars are 2.1–2.5 times higher than the requirements of GOST in the entire range of investigated elongation ratios, starting from 2.07. At the same time, there is an increase in the relative elongation by 5.7–6.8 times in comparison with the initial cast state. The performed analysis of the microstructure and morphology of the secondary phases showed that, with a decrease in the diameter of the bar (with an increase in the total elongation ratio), the average particle size of the α(AlFeMnSi) phase insoluble in the aluminum matrix decreases, which is a consequence of the development of deformation processes during rolling. Additional grinding of inclusions during deformation processing can significantly reduce the possible negative effect of the insoluble phase on the mechanical properties of the resulting bars, in particular, on the property of plasticity. The analysis of the microstructure showed that the bars after rolling and heat treatment do not have cracks, looseness, delamination, and other defects and meet the requirements of GOST 21488–97.

中文翻译：

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低延伸率小直径连铸坯生产合金D16T变形棒材技术开发与试验试验

摘要

本文介绍了用直径为 72 毫米的连铸坯 (CCB) 进行径向剪切轧制 (RSR) 获得的铝合金 D16T 生产棒材的技术的开发和工业试验测试。对于所有棒材直径，轧制棒材的实际尺寸在 ±0.16 毫米范围内，这明显小于 GOST 21488-97 要求规定的直径公差。根据拉伸试验的结果，确定了极限强度、常规屈服强度、相对伸长率和相对压下率的值。D16T合金的极限强度和相对伸长率均满足规范性文件要求，总伸长率大于4.2。就塑性性能而言，获得的钢筋为 2.1-2。从 2.07 开始，在整个研究的伸长率范围内比 GOST 的要求高 5 倍。同时，相对伸长率比初始浇注状态增加了5.7-6.8倍。对二次相的微观结构和形貌进行分析表明，随着棒材直径的减小（随着总伸长率的增加），不溶于铝的α（AlFeMnSi）相的平均粒径基体减少，这是轧制过程中变形过程发展的结果。在变形加工过程中额外研磨夹杂物可以显着减少不溶相对所得棒材机械性能的可能负面影响，特别是对塑性性能的负面影响。