泰钢串罐式高炉炉顶插入件设计优化

 插入件通常安装在高炉料罐中以延长设备使用寿命，而料罐中安装插入件对料罐和炉喉内炉料粒度分布有重要影响。基于泰钢1 780 m3高炉串罐式无钟炉顶系统，建立等比例三维几何模型，分别在改变插入件安装高度和直径的条件下，对炉料从皮带运动至炉喉全过程进行离散单元仿真计算。统计结果表明，安装插入件使大粒径颗粒分布趋于料罐中心，小粒径颗粒分布在料罐壁面附近；下料罐卸料过程中，安装插入件使颗粒流动模式由“漏斗流”转变为“活塞流”，缩小了炉喉径向平均粒径波动范围。当插入件安装在料罐下部锥形区域高度的1/2，且直径等于料罐出口直径时，炉喉中心区域平均粒径相对较大。对实际料罐插入件的设计与安装以及高炉生产具有重要指导意义。     

浅析市政工程沥青路面面层的施工技术

通过分析沥青路面结构形式,探究当前沥青路面的施工常用材料,提出施工具体准备工作要求与管理方法,以期能够全面提升市政工程沥青路面面层的施工水平,解决目前面临的施工技术问题。     

CSP热轧过程中夹杂物周围孔洞的演变

借助于动态显式有限元软件ABAQUS/Explicit,模拟了CSP热轧过程中,板坯厚度方向上不同位置处直径为50μm的Al2O3夹杂物周围孔洞的形成和演变过程。结果表明,对于不同位置处的Al2O3夹杂物,在它们沿轧制方向的前、后部位都形成了孔洞,但前孔洞面积大于后孔洞面积;夹杂物越靠近板坯表面,形成的孔洞越大;热轧过程中,孔洞的演变是一个"愈合—长大—愈合"的动态过程;随着道次的增加,夹杂物前、后孔洞在轧制方向上的投影长度变化与面积变化趋势相一致,而与孔洞尖端夹角的变化趋势恰好相反;孔洞在热轧过程中发生转动,导致前孔洞尖端朝着带钢表面扩展。模拟结果有助于揭示夹杂物周围孔洞与表面缺陷的关系,并为实际生产提供理论指导。     

Quantitative analysis of steel and iron by laser-induced breakdown spectroscopy using GA-KELM

According to the multiple researches in the last couple of years, laser-induced breakdown spectroscopy(LIBS) has shown a great potential for rapid analysis in steel industry.Nevertheless, the accuracy and precision may be limited by complex matrix effect and selfabsorption effect of LIBS seriously. A novel multivariate calibration method based on genetic algorithm-kernel extreme learning machine(GA-KELM) is proposed for quantitative analysis of multiple elements(Si, Mn, Cr, Ni, V, Ti, Cu, Mo) in forty-seven certified steel and iron samples.First, the standardized peak intensities of selected spectra lines are used as the input of model.Then, the genetic algorithm is adopted to optimize the model parameters due to its obvious capability in finding the global optimum solution. Based on these two steps above, the kernel method is introduced to create kernel matrix which is used to replace the hidden layer's output matrix. Finally, the least square is applied to calculate the model's output weight. In order to verify the predictive capability of the GA-KELM model, the R-square factor(R~2), Root-meansquare Errors of Calibration(RMSEC), Root-mean-square Errors of Prediction(RMSEP) of GAKELM model are compared with the traditional PLS algorithm, respectively. The results confirm that GA-KELM can reduce the interference from matrix effect and self-absorption effect and is suitable for multi-elements calibration of LIBS.