摘要本文主要研究了二冷比水量对铸坯C偏析的影响。实验以国内某钢厂150mm2小方坯连铸机生产的82A钢为材料，选取浇次第3、4炉第十一流进行试验，连铸执行1.8m/min的拉速，中包过热度控制在30℃以下。将第11流关闭末端电磁搅拌，分别试验不同二冷比水量，各段配水比例，足辊段：一段：二段：三段=26%：41%：21%：12%。其它流次执行0.5L/Kg的比水量，使用末端电磁搅拌。发现比水量在0.4L/Kg和0.5L/Kg时，铸坯的中心偏析较轻，碳偏析值为1.07。且前者效果略微优于后者。

此外，本文还通过热酸侵试验研究了比水量对低倍组织的影响。使用的是体积分数1:1的盐酸水溶液，将其加热到70℃，放入试样后保温20分钟，之后用水擦洗净表面，用吹风机快速吹干。然后用数码相机拍照后进行疏松、缩孔评级，并通过线比例计算等轴晶率。结果发现，铸坯其比水量的差异对中心疏松和缩孔影响较小。但等轴晶线比例对于比水量的差异较敏感。比水量增大，等轴晶线比例呈降低的趋势。59166

毕业论文关键词：二冷比水量；C偏析；低倍组织；等轴晶率

Abstract The dissertation mainly studies the effect of water ratio in secondary cooling on C segregation of cast slab. The production of 82A steel in a domestic steel 150mm2 billet continuous casting machine for material, select the order of 3, 4 and eleventh pouring furnace flow test, continuous casting 1.8m/min, in the package over heat control in the following 30. Eleventh flow off the end of the electromagnetic stirring, test the difference of two cold water, each water distribution ratio, The foot roller segment: one paragraph: two sections: three sections of =26%:41%:21%:12%. Other flow times the 0.5L/Kg of the water, the use of the end of the electromagnetic stirring. It is found that the center segregation of the cast slab is lighter than that of the water content in 0.4L/Kg and 0.5L/Kg, and the value of the carbon segregation is 1.07. And the former effect is slightly better than the latter.

In addition, the influence of water content on the microstructure was studied by hot acid penetration test. Use is volume fraction of 1:1 hydrochloric acid aqueous solution, it is heated to 70 DEG C, into the specimen after heat for 20 minutes, after the water wiping clean the surface, with a hair dryer and quick drying. Then use the digital camera to take pictures after the loose, shrink hole rating, and through the ratio of the line to calculate the ratio of axial grain. The results show that the difference of the ratio of the cast slab to the center is smaller than that of the center. But the ratio of equal axis crystal line is sensitive to the difference of water quantity. The proportion of equal axis crystal line decreases with the increase of water content.

Keywords: water ratio in secondary cooling; C segregation; Low power organization;  Equal axial grain rate

目录

第一章文献综述 1

1.1连铸坯质量 1

1.1.1连铸坯的表面质量 1

1.1.2连铸坯内部质量 4

1.1.3连铸坯形状缺陷 7

1.2连铸坯质量要求 8

1.2.1连铸坯质量外观检验标准 8

1.2.2表面质量 9

1.2.3弯曲度 9

1.2.4边长测量 9

1.3二冷水对铸坯质量的影响 10

1.3.1二冷基本原理 10

1.3.2二冷控制 11