共查询到18条相似文献,搜索用时 93 毫秒
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通过对造成小方坯表面夹渣缺陷的成因及其对铸坯质量影响的分析,确定质量缺陷评判函数。在表面夹渣严重程度与缺陷的原因之间建立一一对应关系。并依据各工艺参数对小方坯表面夹渣质量缺陷的影响程度及生产经验,对评判函数中的权重提供了动态分配方案。以生产厂小方坯连铸机的实际生产为样本,收集连铸生产工艺参数,对小方坯表面夹渣缺陷的判定情况进行对比验证。数据结果表明,模型判定结果与实际检测结果基本吻合,达到了预报和分析连铸坯质量的目的,生产厂小方坯表面夹渣缺陷在线质量预报显示,预报的准确率超过预期目标值。结合判定实例,分析生产厂小方坯表面夹渣缺陷产生的主要原因,并提出解决措施。 相似文献
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分析了小方坯表面夹渣产生的原因,并采用扫描电镜能谱分析等方法对小方坯表面夹渣进行了调查,对其来源进行了讨论,提出预防措施;措施实施后,取得了明显效果。 相似文献
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分析了产生冷轧板卷夹渣类缺陷的连铸工序因素。结果表明,150 t转炉-吹氩站-LF-CAS或RH-(900~1 020) mm×210 mm连铸流程生产低碳铝镇静钢时,水口插入深度130~155 mm时热轧板缺陷指数远低于水口插入深度125 mm和160 mm时缺陷指数;浇铸时钢包水口自开和烧氧打开钢中平均总氧含量T[O]分别为15×10-6和25×10-6;通过下渣检验仪控制钢包至中间包的下渣量,热轧夹渣类缺陷指数显著降低。通过控制中间包钢水量,改进中间包水口结构;优化浸入式水口插入深度,提高钢包自开率和下渣检测使用率,采用低钠结晶器保护渣,使热轧板夹渣翘皮指数由原先的3.45降到0.73。 相似文献
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连铸坯表面夹渣的原因分析及解决措施 总被引:2,自引:0,他引:2
表面夹渣是连铸坯常见的表面缺陷,直接影响成品的表面质量.通过分析连铸坯表面夹渣问题产生的原因,制订实施了保持结晶器内钢水的稳定性、选择合适的保护渣及结晶器的振幅、振频等措施,使连铸坯表面夹渣的问题得到了有效的控制. 相似文献
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Based on an inverse algorithm and a full-scale heat transfer model of slab/mould, the non-uniform temperature fields of mould and slab are obtained. Considering the formation mechanism and heat transfer characteristics of the slag films and air gap, a mathematical model of the heat transfer between the liquid/solid slag films and air gap is further developed. According to the model, the non-uniform distributions and evolution of liquid/solid slag films and air gap are comprehensively revealed, which proposes a theoretical foundation for exploring the complex heat transfer of mould/slab and provides a helpful tool for further improving the casting parameters and operations. 相似文献
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Over the last decade,various Fe-Ni alloys have been developed at Baosteel using the EAF-AOD-LFVD-CC route. This paper first reveals the main cause of defects in Fe-Ni alloys,including surface edge cracks on hot-rolling strips and slivers on cold-rolling strips of Fe-36% Ni alloy. Then,the material properties and in-situ solidification behavior w ere experimentally investigated. The gas content and average diameter of the inclusions in Fe-36% Ni alloy that occur along the EAF-AOD-LF-VD-CC route w ere also investigated via potentiostatic electrolysis using a non-aqueous organic electrolytic. Furthermore,the heat transfer and solidification in a continuous casting mold w ere predicted based on an inverse heat transfer model using the measured mold temperature. Experimental results show that the gas content,w hich is 0. 001 5% in a continuous casting slab,and the average diameter of the inclusions both decrease during the metallurgical EAF-AOD-LF-VD-CC process. The average diameter of the inclusions in a continuous casting slab is ~ 18 μm,w hich tends to induce slivers during subsequent cold-rolling process. Experimental in-situ solidification results show that the mushy zone betw een the liquidus and solidus of Fe-Ni alloy is much narrow er than that of plain carbon steel. Stresses are generated during continuous casting,primarily due to the thermal contraction of a few percentage points,and any strain applied to the steel w ithin this temperature region w ill cause cracks to propagate outw ard from the solidification front betw een the dendrites. Numerical simulation results illustrate that heat flux and shell thickness are uneven across the w idth of the mold,particularly the shell thickness close to the edge of the slab surface in the fixed face is 6-mm thinner than that at the slab center. Based on these results,the incidence of surface defects in Fe-Ni alloy can be greatly reduced by the adjustment and optimization of its refining and continuous casting process. 相似文献
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