2A50合金正反挤压棒粗晶的对比

Comparison of Coarse Grains of 2A50 Alloy Rods with Direct Extrusion and Indirect Extrusion

阐述了２Ａ５０合金反挤压棒材粗晶区的分布特征，以及与正挤压棒材粗晶环的差异。通过对该合金正反挤压棒粗品的试验研究，发现２Ａ５０合金反挤压棒材粗晶区由两部分组成：最外层深度小于２．０ ｍｍ的粗大晶粒区和由粗晶区向中心延伸的小晶粒区。这同正挤压棒材粗晶环有很大差异。试验结果表明：２Ａ５０合金及挤压棒材边部由粗晶区向中心延伸的小晶粒区是不完全再结晶组织，不应属于粗晶环。

The distribution features of coarse grain zone in 2A50 alloy rods produced by indirect extrution process, and the differences of coarse grain ring between indirect extrusion and direct extrusion are introduced. Experimental result shows that the coarse grain zone of 2A50 alloy rods produced by indirect extrusion consists of two parts: the coarse grain zone with less than 2.0mm depth from outermost surface. and the small grain zone emended from coarse grain zone to the central part of the rods. These features are diffent greatly from those of rod produced by direct entrution. Experiments show that. the small grain zones exended from the coarse grain zones into the central parts of 2A50 alloy inverted extrusion rods are incomplete recrystallization structures, not coarse grain rings.