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介绍了管坯生产及其质量。对生产方式进行了比较,认为采用连铸坯生产无缝钢管是最经济合理的,工序简化,消耗降低,连铸坯比轧坯便宜10-15%,并且质量好。用连铸坯生产无缝钢管势在必行。 相似文献
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为使连铸坯吊具逐步适应现代化大型钢铁联合企业快节奏、高效率的生产需要,根据邯钢使用连铸坯吊具的生产实践,总结了各种连铸坯吊具的特点。 相似文献
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为使连铸坯吊具逐步适应现代化大型钢铁联合企业快节奏、高效率的生产需要,根据邯钢使用连铸坯吊具的生产实践,总结了各种连铸坯吊具的特点。 相似文献
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高效连铸的主要目的是获得高的铸坯无缺陷率,连铸技术工作者一直反连铸坯质量作为连铸发展的一个方向,连铸坯存在的缺陷主要表现为裂纹、偏析、非金属夹杂及鼓肚变形等,这些缺陷的形成与连铸坯凝固过程中的传输现象密切相关。 相似文献
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连铸坯表层微观组织直接影响其表面质量,研究微观组织演变过程与工艺条件的关系对认识机制并优化连铸工艺具有重要意义。根据连铸坯传热特点,利用凝固过程热模拟方法再现铸坯表层传热过程,通过液淬实验观察了连铸坯表层微观组织的演变过程,并比较了热模拟铸坯和实际铸坯在传热、枝晶生长速度和微观组织方面的相似性。结果表明,热模拟实验可以很好地反映连铸条件下的传热及微观组织演变过程,为研究工艺条件对铸坯表层微观组织的影响提供了可行的途径。在所选模拟连铸条件下,0.1%C低碳钢的连铸坯表层奥氏体晶粒尺寸(D)与凝固时间(t)符合关系式:D=80.74×ln(t+2.95)-90.49。 相似文献
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连铸工艺对板坯裂纹的影响及防止措施 总被引:1,自引:0,他引:1
连铸坯的裂纹是造成连铸坯报废的主要原因,针对连铸板坯的宽面纵裂和角部横裂问题进行了金相组织检验和热模拟试验,对铸坯裂纹产生的原因和机理进行分析,提出了防止铸坯产生裂纹的具体措施。 相似文献
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对薄板坯连铸连轧生产低碳铝镇静钢浇次第一炉开浇初期的中间包钢水取样,运用ASPEX扫描电镜分析了钢中夹杂物数量、尺寸及成分的变化规律。结果表明,二次氧化主要有2种:大气氧化和中间包耐火材料及卷渣造成的氧化。夹杂物的变化受二次氧化方式主次不同影响较大,在本研究的2个浇次中,中间包耐火材料及卷渣造成的二次氧化持续时间较大气氧化长,造成夹杂物数量较多和大量高熔点Al2O3夹杂的持续存在,其平均尺寸也较大,对钢水洁净度影响更大,可见在工业实践中,耐材和卷渣引起的二次氧化也值得高度重视。 相似文献
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利用氧氮分析仪和大样电解法对某厂采用210t BOF—220t LF—CC所生产的低碳铝镇静钢不同浇铸长度头坯夹杂物进行研究,并与正常坯相比较,得到结论如下:随着浇铸长度的增加,头坯中w(T[O]),w([N])和大型夹杂物数量均逐渐下降;头坯中夹杂物主要为TiN,SiO2,Al2O3-SiO2和Al2O3-MgO-CaO复合夹杂物,另外还发现少量的MgO夹杂物;头坯夹杂物数量增加的主要原因是钢水二次氧化、中间包覆盖剂和结晶器保护渣卷入;另外,钢包引流砂和中间包内衬也是导致头坯中夹杂物数量增加的原因。建议该厂该低碳铝镇静钢头坯的切废长度为大于4.0m。 相似文献
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研究了低碱度、低氧化铝精炼渣对帘线钢夹杂物控制情况。试验采用LD→LF精炼→软吹Ar→连铸工艺生产帘线钢,在碱度1.0、Al2O3质量分数为5%左右的精炼渣成分控制条件下,钢中酸溶铝AlS的质量分数控制在0.000 5%左右,进而控制夹杂物中Al2O3质量分数在22%以内,使得帘线钢中氧化物夹杂MnO-Al2O3-SiO2类、CaO-Al2O3-SiO2类复合夹杂物实现了良好的塑性化控制。根据分析,在帘线钢夹杂物去除方面,软吹氩处理对钢中CaO-Al2O3-SiO2系复合夹杂物去除效果比对MnO-Al2O3-SiO2类夹杂物更加明显;在成分控制方面,钢液中AlS含量随着炉渣碱度、炉渣Al2O3质量分数的升高而升高,而夹杂物中Al2O3质量分数会随着钢液中AlS含量升高而升高。 相似文献
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Desulfurization performance with low binary basicity refining slag in 72 grade tire cord steel was calculated using FactSage and it is found that sulfur content in steel decreases with the increase of basicity of slag, MgO content in slag and slag/steel ratio while sulfur partition ratio between slag and steel increases gradually with the increase of basicity of slag as well as MgO content. Experiments were carried out and the results are of great agreements with theoretical calculation. Then industrial application tests were performed in a domestic plant and good results were achieved. Sulfur content in steel decreases gradually during refining process, as a result, sulfur content in the billets is controlled in the range of 0.007 1%-0.008 1%. Sulfur content in steel refined with slag basicity of 1.21 is lower than that of 1.02, while the plasticity of oxide compound inclusions is a little better controlled in low basicity heats. Using refining slag with basicity of 1.0-1.2 and MgO content of 5%-10% and reducing the slag takeover of LD are favorable for improving the desulfurization performance and the plasticity of inclusions during the industrial production. 相似文献
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Alumina‐based inclusions have a detrimental effect on castability and the surface quality of the LCAK steel sheet, thus they are expected to be removed from the steel. In order to get the detailed transient characteristics of inclusion aggregation and removal after Al addition, laboratory experiments were performed to study the formation of alumina inclusions during Al‐killed process of low carbon steel at 1873 K under no‐stirring condition. The characteristics of the alumina‐based inclusions in terms of amount, size, and morphology were investigated. The results showed that the evolution of the AF (area fraction) and average size of Al2O3 inclusions after deoxidation was divided into three stages: 0–9 min, aggregation was dominant; 9–22 min, floating was dominant; after 22 min, both the AF and size decreased slowly. Accordingly, the stirring was suggested to be strengthened in the initial 9 min under stirring condition to promote the removal of large inclusions. Based on the correlation between inclusion morphology and holding time, a simple precipitation and growth mechanism of alumina inclusions was proposed, which consisted of three main stages: precipitation stage of Al2O3 single particles, aggregation stage, and sintering stage of aggregated inclusions. And it was implied that the Ostwald‐Ripening can be finished up within 20 min. 相似文献