铸带上下表面裂纹分布不均的原因分析

A Study on Unsymmetrical Distribution of Cracks in Up-and-Down Surface Layers of Product by Strip Casting Technique

双辊薄带连铸方法生产的铸带上下表面裂纹分布不均匀,呈现上表面多而下表面少的现象。本文从热力学角度对该现象进行分析,说明上表面较大的温度梯度使其更易于产生裂纹;从铸带变形的角度进行分析,发现上表面有较大的变形量,该变形量大小与弧形板的形状及铸带所受外力有关,这也使其上表面易于产生裂纹。有别于以往对裂纹这一现象的研究,本文不关心裂纹形成的先天因素,而是通过对铸带后天环境的分析,提出在熔池之外减少裂纹的新思路。

It is known that there is an unsymmetrical distribution of cracks in the up - and - down surface layers of the products obtained by strip casting technique and the cracks in the upside surface layer are more than those in the downside layer. The reasons by which the unsymmetrical distribution of creaks is formed are studied in the view of thermodynamics in this paper. The unsymmetrical distribution may be attributed to a larger temperature gradient and a larger deformation existed in the upside layer, and the deformation depends very much on external force and the shape of the arched board, which are different from the results reported by the past publications. Also a new way to reduce cracks is proposed.