中厚板边裂的形成与控制

边裂是中厚板常见的表面缺陷之一。连铸坯角部表面横微裂和皮下气泡缺陷及轧制中轧板上下表面不均匀变形是边裂产生的主要原因。通过控制钢中w[Als]，避免高温浇注，选用合适的保护渣，控制矫直温度，保持铸机状况良好，改善铸坯角部的表面质量；通过减小横轧展宽量，提高板坯加热均匀性，保证轧制压下量，优化轧机配辊，减小轧件边部的不均匀变形？可大大降低中厚板边裂的发生率。

Formation and Control of Edge Cracks on Medium and Heavy Plate

Edge cracks often appear on the medium and heavy plate, whose formation can be traced to two factors, i.e. the extension of the corner surface transversal cracks and subsurface air bubble of slab through rolling and the asymmetrical shape change of the top and bottom surface in rolling. The corner surface quality of slab can be improved by controlling w[Als] , avoiding casting at high temperature, choosing the straightening temperature, controlling the precision of secondary cooling, and keeping caster in good state. In rolling, the asymmetry of shape change on plate can be resolved by reducing the deformation rate of cross wedge rolling, improving the heating uniformity of slab, ensuring the rolling reduction, and optimizing roll arrangement. With these measures, the formation of edge cracks on medium and heavy plate can be significantly checked.