Preparation of special silicon steel grade MgO from hydromagnesite

A preparation technology of MgO powder used in special silicon steel from hydromagnesite mineral has been developed. The preparation technology includes the following steps： （1） calcining the hydromagnesite at 700-750°C for 1.5-2 h; （2） hydrating the calcined hydromagnesite to be slurry containing the solid-liquid ratio of 15-20 g？L？1; （3） acquiring Mg（HCO3）2 solution by carbonating the slurry, the carbonation temperature, CO2 pressure, and end point PH value of carbonation are less than 40°C, 0.4-0.6 MPa, and 7 respectively during the carbonation process; （4） preparing precipitated basic magnesium carbonate by thermally decomposing the Mg（HCO3）2 solution at 90-100°C; （5） obtaining the MgO product by calcining the precipitated basic magnesium carbonate at 850-950°C for 30-60 min, and adopting flowing nitrogen during the cooling process. By using this technology, more than 80wt% magnesium in hydromagnesite mineral can be extracted, and high-performance MgO products used in special silicon steel can be ob- tained.

Technology innovations on high quality special steel products

Because special steels are the basic materials for industrialization,a national R&D program on special steel technology for high quality products have been granted to promote the special steel production and applications since 2008.Since then,great progresses have been achieved on ferritic stainless steel sheets,heat resistance steel pipes and tubes,microalloyed forging steel bars,and mould steel forgings for hot working. The ratio of ferritic stainless steel sheets produced by TISCO and Baosteel has been promoted through technology innovations and increased 42%and 48 in 2009 respectively.439M steel sheets have been used to exhaust system,and 444 steel sheets have been applied to kitchen and architecture.The production technologies for heat resistance steel pipes and tubes(T/P92,S3043,S31042 steels) have been developed in Baosteel and Pansteel to meet the market requirements.Meanwhile,the round bloom technology has been initiated in Xingcheng Steel.The new technologies for microalloyed forging steels,low cost steel bar,and tailored steel and components,were proposed by CISRI based on the understanding of precise chemical composition and segregation control.And the applications of microalloyed forging steel bars have been promoted remarkably.The researchers have developed high quality mould steel technologies,heavy section forgings of 718 steel,high premium H13 steel blocks and large diameter mandrels used for seamless pipe rolling.The technology innovations of the program could lead to the progress of production technology in special steel sheets,pipes,bars and forgings,and meet the demands from market.For the moment,it is actually believed that there still strong requirements for the technology innovations on special steels.

The development of China's special steel and the application prospects of spray-formed materials

Suggestions have been put forward speeding up the development of high-level tool steel and mold steel in China based on the analysis of products and development status of special steel home and abroad. Feasibility and necessity to produce high-level tool steel and mold steel by applying the spray forming method in future have been put forward.

Development of ultra high strength special steels and wrought nickel base superalloys

Ultra-high strength special steels and wrought Ni-base superalloys are been ever increasingly applied in aircraft and aerospace,power generation,oil-gas and other industries.The development of those materials is driven by tougher working conditions,higher efficiency,environment consideration,resource limitation and cost reduction. This presentation will focus on the development of ultra high strength special steels and wrought Ni-base superalloys in aircraft industry. The examples of ultra-high strength steels include: (1) Ultra-high strength stainless steels for landing gear and other structures; (2)High speed and high temperature main shaft bearing steels; (3) Ultra-high strength steels for jet engine main shaft. New and modified Ni-base superalloys will be discussed by examples of (1 )Low cost,process-friendly superalloys with higher performance; (2)Modification of hard-to-processed superalloys. Future development of those materials will be addressed.

Study on the properties and application of the steel slag special fine aggregate

The physical properties, grading stability and application stability of the steel slag special fine aggregate （diameter≤0. 8mm） at Baosteel were analyzed in this study, and the mechanical and working properties were studied when the aggregate was applied to concrete. The： result shows that the aggregate has special advantages of hardness and wear-resistance, so it can be used as an excellent road surface material. The concrete mixed with the steel slag special fine aggregate exhibits good mechanical properties and working properties,which is safe and reliable.

异形双曲面楼承板节点构造及施工方法

为解决异形双曲面钢筋桁架组合楼板施工的难题,对某工程异形双曲面楼承板施工过程中的几种技术措施进行分析和总结,形成较为完整的施工工艺。总结的单元化、以直代曲等技术可为滑雪场、商业楼等异形双曲面钢筋桁架组合楼板施工提供借鉴。

Classification of steel based on laser-induced breakdown spectroscopy combined with restricted Boltzmann machine and support vector machine

In recent years,a laser-induced breakdown spectrometer(LIBS)combined with machine learning has been widely developed for steel classification.However,the much redundant information of LIBS spectra increases the computation complexity for classification.In this work,restricted Boltzmann machines(RBM)and principal component analysis(PCA)were used for dimension reduction of datasets,respectively.Then,a support vector machine(SVM)was adopted to process feature information.Two models(RBM-SVM and PCA-SVM)are compared in terms of performance.After optimization,the accuracy of the RBM-SVM model can achieve 100%,and the maximum dimension reduction time is 33.18 s,which is nearly half of that of the PCA model(53.19 s).These results preliminarily indicate that LIBS combined with RBM-SVM has great potential in the real-time classification of steel.

Baosteel's progressive advance in manufacturing high performance alloys

Backed by over 50 years time-tested experience in alloys manufacturing,Baosteel Special Steels play the leading role in the development and production of high performance alloys in China.The key alloys we produce for the domestic and foreign top-end market cover the Ti-alloys,and structural steels.The alloy melting processes include VIM,VAR,ESR,EB &PAM,EAF,AOD,VOD,LF,VD and the casting processes include IC,CC.The metal forming processes involve forging & isothermal forging,hot &cold rolling,extruding,drawing,and sheet metal operations.The production capability has been further strengthened by our unparalleled production lines and state-of-the-art facilities, comprehensive product analysis,superior quality assurance to national and international standards and all-round customer service.

特钢棒材表面裂纹视觉检测研究

针对特钢棒材表面裂纹缺陷人工检测效率低、漏检率高且无法与自动化修磨技术相结合等问题,提出一种棒材表面裂纹的视觉检测方法。首先基于棒材旋转,利用线阵相机沿棒材周向采集到中心和边缘亮度一致的二维图像;然后,采用双边滤波和增强的预处理方法提高棒材表面图像质量,在去除图像噪声的同时保留裂纹局部细节,增强裂纹与背景区域的对比度;再根据求补集原理去除干扰裂纹检测的亮点区域;接着将最大类间方差法与Canny算子结合,自适应选取边缘阈值,提高边缘检测精度;最后,根据所选区域的面积、长宽比以及与水平方向夹角等几何特征筛选出真正的裂纹,将裂纹缺陷位置信息坐标化。实验及研究结果表明该检测方法能够替代人工,准确检测和定位特钢棒材曲面的裂纹,为后续棒材裂纹的自动化修磨提供基础。

特钢棒材砂带自动磨削系统轨迹规划

为提高特钢棒材表面缺陷去除效率,改善工人工作环境,以六自由度机械臂为主驱动部件,结合砂带磨削机构建了特钢棒材自动磨削系统。根据在其操作空间中设计连续N型缺陷磨削路径,并构建砂带磨削力模型。在关节空间中运用7次非均匀B样条开曲线建立单N型磨削路径与关节轨迹的映射关系。构建包含关节速度、力矩与空间路径误差约束的时间最优轨迹规划模型,并利用惩罚函数与自适应遗传算法求解。仿真获得各关节磨削轨迹并对比分析空间路径误差约束,可提高自动磨削系统运动的稳定性。搭建了轧制缺陷视觉引导的自动磨削系统,并实验验证连续N型缺陷磨削路径的有效性。

成捆特钢棒材端面字符识别算法研究

为实现特钢棒材生产信息的全流程可追溯,分析特钢棒材生产环境及形状特点,采用基于双标志点的标记方案进行标记并利用机器视觉技术实现成捆特钢端面字符的识别。首先,采用Hough变换将成捆特钢棒材端面图像分割成单根;其次,采用基于小波变换的图像增强算法完成单根特钢棒材端面图像的增强;再次,将MSER算法和边缘检测算法相结合完成单根特钢棒材字符区域的检测,并基于投影法完成字符的分割;最后,通过创建和训练SVM分类器完成每一根特钢棒材端面字符识别,并将成捆特钢棒材端面字符识别结果输出保存。结果表明,新算法可以满足成捆特钢棒材生产过程中字符识别要求,字符识别准确率可达到97.35%。新算法将Hough变换、基于小波变换的图像增强算法、MSER算法、边缘检测算法、投影法及SVM分类器等算法融合到特钢棒材端面字符识别过程中,为特钢棒材生产过程中的信息获取、信息传递及信息追溯的技术实现提供了参考。

特殊钢大方坯碳偏析遗传性及其轧材组织特征研究

通过跟踪特钢20CrMnTi和42CrMo的生产,分别对同一炉次铸坯和轧材取样,分析其低倍组织和碳偏析。结果表明:铸坯中的碳偏析会遗传到轧材,轧材出现锭型偏析,轧材低倍组织与铸坯凝固结构相关。针对轧材的锭型偏析区域,用光学显微镜观察其显微组织,发现锭型内外区域的显微组织不同,并且20CrMnTi的轧材存在带状组织,这对组织性能的均匀性不利,影响成品质量。

特殊钢大棒材连轧规程的研究

为方便研究特殊钢大棒材的现场生产条件、轧制工艺参数对其在轧制过程中变形、温度、轧制力矩的影响,采用C语言编写源程序、MFC模块编写人机交互界面,开发了特殊钢大棒材连轧规程系统。通过本系统对20CrMnTi齿轮钢大棒材的实际轧制工艺参数进行计算,计算值与实测值进行比较,得出计算值与实测值吻合较好。验证了该系统可以较准确预测轧件在轧制过程中温度、轧制力、轧制力矩和能耗的变化情况,为研究特殊钢大棒材的生产工艺以及质量和组织的控制提供可靠的工艺参数。

优特钢棒材冷床技术

根据冷床的设计经验及棒材生产线的工艺实践,提出了标准冷却、缓冷快过及强制冷床冷却等模式,以满足优特钢车间的生产需要。与常规冷床相比,此冷床冷却后的棒材平直度更高,可减少某些规格的优特钢产品的个别后续精整工序,为企业节约成本,带来较高收益。

钢骨增强异形柱框架节点受力性能及有限元分析

为了解决异形柱结构节点薄弱的问题,提出了在异形柱框架节点核心区加入钢骨的改善措施,对钢骨增强异形柱节点和同等条件下未被增强的异形柱节点进行了拟静力试验研究,研究了试件的承载能力、变形能力等指标,分析了钢骨对混凝土异形柱受力性能的影响。采用ANSYS有限元分析软件对试件进行了非线性数值模拟。研究结果表明:ANSYS有限元模型可以基本反映节点的受力过程。钢骨增强了异形柱节点的承载能力和变形能力。钢骨通过发挥其强度作用直接参与节点核心区受力,在异形柱节点核心区加入钢骨能够提高核心区混凝土的抗压能力。钢骨增强的异形柱节点的受力性能得到了改善。

特殊钢棒线材轧制工艺技术的发展

本文对当今特殊钢棒线材轧制的新工艺、新技术进行了分析、研究。围绕着无头轧制、脱头轧制、在线补充加热、精密轧制、单一孔型轧制及自由尺寸轧制、低温精轧、在线热处理等特殊钢棒线材轧制工艺技术进行了分析,为特殊钢棒线材轧制工艺技术的引进、应用、开发与研究提供了思路。

特殊钢棒线材轧制工艺的发展趋势

通过对世界特殊钢主要生产国家的棒材生产品种、规模、坯料断面、产品质量和发展方向等研究,对我国特殊钢厂的引进和改造提出建议。

超厚异形筏形基础粗大钢筋加工及安装质量控制技术

昆明春之眼商业中心主塔超厚异形筏形基础钢筋施工中,针对钢筋直径粗、层数多、局部钢筋交叉密集,混凝土厚度厚、强度等级高、施工困难等特点,其筏形基础粗大钢筋加工及安装质量控制成为关键技术。

钢骨增强异形柱框架中节点的抗震性能试验

通过对1根普通的和2根钢骨增强的异形柱框架中节点进行低周往复荷载试验,分析异形柱框架中节点的破坏特点、承载力及延性、耗能能力、累积损伤等,研究钢骨对异形柱框架中节点的抗震性能的影响.研究表明:钢骨明显改善了异形柱框架节点的破坏形态,提高了承载力及延性、耗能能力,降低了累积损伤程度,抗震性能较好;且对于抗震性能提高的效果加入槽钢的异形柱框架中节点优于加入T型钢的异形柱框架中节点.

20Cr棘爪钢异型材的冷轧

研究了用１８０ｍｍ轧机轧制异型断面棘爪钢的可行性。实验确定了保证棘爪钢断面形状和机械性能的冷轧变形率为４８％，拉伸矫直量以不小于０．３％为佳。