板坯大型夹杂物研究

学号：

HEBEI UNITED UNIVERSITY

毕业论文

G RADUA T ETHESIS

论文题目：板坯大型夹杂物研究

学生姓名：

专业班级：

学院：冶金与能源学院

指导教师：教授

年月日

摘要

本文以唐钢最新投产的FTSC连铸技术生产的板坯为研究对象，将板坯加工成Φ50×130mm的圆柱形试样。通过大样电解实验，经过电解、淘洗分离碳化物和分级称重等步骤得到了试样中的大型夹杂物，再用KYKY-2800型扫描电子显微镜对夹杂物进行定性分析。研究表明：板坯中的大型夹杂物主要来源于脱氧产物、结晶器保护渣和中间包覆盖剂的污染，其次是水口的熔损；大型夹杂为球形的钙铝酸盐夹杂、透明的SiO2夹杂和复杂化合物夹杂。

此外，根据试验结果和讨论提出相应的改善措施。如：选用优质原料、转炉要提供优质的钢水、钢包底吹氩搅拌、采用全程保护渣浇注、优化中间包流场和减少液面波动等。通过研究了解大型夹杂物的来源、成因以及影响因素等，以期找出减少板坯中大型夹杂物夹杂物的办法，提高钢的质量。

关键词：板坯；电解；大型夹杂物；来源

In this paper, We introduce the continuous casting technology of the latest production of FTSC Tangshan Iron and Steel Production slab as research object, in which Φ50×130mm slab is processed into a cylindrical sample. By large sample electrolysis experiment, after electrolysis, separating washing steps such as carbides and classification, we have been weighing the sample in the large inclusions, and then by KYKY-2800 scanning electron microscope for qualitative analysis of inclusions. The results show that: a large slab of deoxidation products mainly from inclusions, mold powder and tundish covering flux of pollution, followed by the outlet of the melt loss; large inclusions of calcium aluminate inclusions are spherical, transparent SiO2 inclusions and complex mixture of compounds.

Moreover, according to the corresponding test results and discuss we can propose improvements, such as: high quality raw materials, the converter to provide high-quality steel, ladle bottom blowing argon stirring, the use of flux throughout the casting, the tundish flow and optimized to reduce surface fluctuations. Through research to understand the source of large inclusions, causes and contributing factors, so as to reduce the slab in identifying large inclusions to approaches to improve the quality of steel.

Key words: slab, electrolysis, large inclusions, source

引言 (1)

1 文献综述 (2)

1.1 板坯连铸的发展 (2)

1.2 板坯连铸的应用技术 (3)

1.3 板坯连铸的工艺特点 (6)

1.4 钢中夹杂物的分类与分布特点 (7)

1.4.1 夹杂物的分类 (7)

1.4.2 夹杂物的分布特点 (10)

1.5 夹杂物对钢质量和性能的影响 (11)

1.6 生产工艺对夹杂物的影响 (14)

1.6.1 转炉过程钢液夹杂物的控制 (15)

1.6.2 精炼过程夹杂物的控制 (17)

1.6.3 连铸过程钢水纯净度的控制 (18)

2 板坯内的大型夹杂物 (22)

2.1 大型夹杂物的来源 (22)

2.2 影响大型夹杂物的因素 (22)

2.2.1 脱氧制度的影响 (22)

2.2.2 浇注过程的影响 (23)

2.3 大型夹杂物对钢材质量的影响 (23)

2.4 减少大型夹杂物的措施 (24)

3 实验研究板坯中大型夹杂物 (25)

3.1 研究背景 (25)

3.2 研究目的 (25)

3.3 研究内容 (26)

3.4 实验室研究 (26)

3.5 大样电解实验 (27)

3.5.1 大样电解的特点 (27)

3.5.2 实验原理 (28)

3.5.3 试验方法 (28)