厚板坯气泡形貌、分布及携带夹杂物的原位分析

In-situ analysis on morphology,distribution and entrapped inclusions of bubbles in thick slab

摘要: 对管线钢X70厚板坯进行分层刨削, 并对厚板坯内气泡尺寸、形貌及其携带夹杂物的情况进行原位分析.结果表明, 厚板坯内约94%的气泡直径在200μm以下;厚板坯皮下8 mm范围内气泡及其携带的夹杂物缺陷较多, 继续深入刨层, 基本上难以发现明显的气泡及其携带的夹杂物, 只在个别位置发现了少许气泡, 且表现出了一定的偶然性;气泡形态以单个气泡和孪生气泡为主, 还有少许葫芦形气泡以及“四瓣”形气泡;发现了四种夹杂物的存在形式:氧化物、团簇状夹杂物、气泡群夹杂物以及夹灰.

Abstract: The morphology, distribution, and entrapped inclusions of bubbles in thick slab of X70 pipeline steels were investigated by peeling layer.The results show that the diameters of 94%bubbles in thick slab are less than 200μm;the bubbles and the entrapped inclusions are common in 8 mm depth from the slab surface, but the defects are hardly found as peeling deeper into the middle of slab, only a small number of defects are shown, presenting a random distribution in this area;the main morphology of bubbles existing in slab are single bubbles and twin bubbles, the calabash bubbles and petal bubbles are also found;the inclusions are mainly in four existent forms:oxides, aggregation in clusters, bubbles in clusters, and ash inclusions.