方坯加热炉二维温度模型

开发了一种可用于方坯加热炉加热制度分析以及实时计算的方坯二维温度模型,该模型包括沿炉长方向的温度分布计算,方坯表面热流密度计算以及方坯内部二维热传导计算。加热炉炉长方向炉温分布根据热电偶测温数据获得;根据总括热吸收率方法计算方坯上、下表面的热流密度数值,并由此计算方坯侧面热流密度;对方坯内部热传导建立二维差分方程组,并利用ADI和TDMA算法进行求解。通过埋偶试验验证了模型方法的正确性,在某钢厂高线加热炉的运行测试表明,模型能够用于辅助制定钢种的加热制度,在线计算则表明了模型计算的通用性和实时性。     

基于加热炉内炉气非灰辐射特性的总括热吸收率

基于加热炉内炉气的非灰辐射特性和传热机理,给出总括热吸收率的一种求解思路.以某轧钢厂的一台步进梁式加热炉为例,计算了钢坯表面热流沿炉长方向的分布,并反算求解总括热吸收率.研究工作为应用拖偶实验数据进行总括热吸收率的参数辨识提供了必要的补充.     

连铸二冷气雾冷却过程导热反问题分析

建立了连铸二冷气雾冷却一维非稳态导热过程中由铸坯内部单个测温点测得的温度值反算表面未知温度和表面热流密度的数学模型,利用热平衡法建立各节点差分方程,引入灵敏度系数,通过牛顿迭代法优化假设初始值。为了验证该数学模型的正确性,在铸坯表面施加已知热流密度,结果表明反算得到的热流密度与已知热流密度吻合较好。分析了连铸二冷过程中铸坯表面热流密度的变化规律。     

连铸二冷气雾冷却过程导热反问题分析

建立了连铸二冷气雾冷却一维非稳态导热过程中由铸坯内部单个测温点测得的温度值反算表面未知温度和表面热流密度的数学模型,利用热平衡法建立各节点差分方程,引入灵敏度系数,通过牛顿迭代法优化假设初始值。为了验证该数学模型的正确性,在铸坯表面施加已知热流密度,结果表明反算得到的热流密度与已知热流密度吻合较好。     

钢管张力减径过程传热模型

为了提高钢管张力减径过程的轧制质量、降低能耗以及控制终轧温度的准确性,从而为钢管出炉温度提供科学设定依据,通过对传热机理分析,建立了钢管张力减径过程传热模型,给出了除鳞、轧制及空冷阶段钢管边界热流的计算式.基于塑性材料的变分原理,建立了轧制变形区的变形热计算模型.结果表明:变形热对钢管温度分布影响不可忽略;该模型能真实反映钢管在张力减径过程中的温度变化,与实测结果吻合较好,可用于钢管再加热和张力减径过程中的参数分析及工艺优化.     

珠钢薄板坯连铸结晶器传热特征的研究

薄板坯连铸结晶器的传热过程直接影响到铜板的寿命，因此有必要研究薄板坯连铸结晶器的传热特征。根据在线实测的铜板温度以及薄板坯连铸机冷却参数，建立了薄板坯结晶器铜板传热模型，计算并验证了结晶器热流密度的分布函数。结果表明，宽度方向上铜板温度和热流密度分布具有相似的规律性，距离弯月面越近，热流密度和温度的波动越大；弯月面处热流密度值超过4．4MW／m^2，结晶器热面温度高于铜的再结晶温度，这是造成结晶器铜板被侵蚀的主要原因。     

钢管冷却喷淋水量对换热系数的影响

 采用一种钢管外喷淋装置,通过在钢管中预埋热电偶测量钢管冷却期间的温降曲线,研究了喷淋水量对钢管冷却强度的影响。利用有限元模拟软件对测量结果进行分析,建立了钢管表面对流换热系数和水流密度的数学关系模型,将模型嵌入了钢管温度场计算软件当中,软件的计算精度进行了工程验证。结果表明,融合了该换热数学模型的钢管温度场模拟软件计算精度达到90％以上。     

高压电站锅炉用无缝钢管A热处理工艺研究情况

主要针对高压电站锅炉用无缝钢管A热处理工艺进行研究,并结合热处理相关理论,通过冷钢管回火实验和模拟热料加工在线退火实验,找出无缝钢管A软化的途径。实验结果表明:冷钢管回火时,可以选择780~800℃区间回火,保温时间要求0.5 h以上可形成的组织为回火马氏体;热态钢管在线退火时,可选择温度在750~780℃之间,保温时间两小时以上时组织为F+C。     

板坯连铸热顶结晶器研究

连铸热顶结晶器对改善结晶器传热状况影响显著。在结晶器热面弯月面处热镀低导热性材料,增加热阻、降低热流密度、提高初生坯壳均匀性,从而改善铸坯表面质量。数值预测每增加1 mm镀层厚度,热面温度提高10~15 K;现场在线热电偶监测数据证实,热顶结晶器能够降低铜板温度5~15 K;热顶结晶器能够降低结晶器进出口水温差(即平均热流密度),促进初生坯壳均匀生长。将热顶结晶器应用到高碳钢连铸生产,显著降低了连铸纵裂发生率。     

水射流冲击冷却过程靶面热流密度测试方法的改进

为了准确测量水射流冲击冷却过程靶面热流密度,提出在靶体背侧增加绝热材料,采用单点测温,使用一维导热反问题计算靶体表面热流密度的方法.实验数据分析显示,采用该方法对靶体背侧温度预测的相对误差±5%以内的概率为93%以上,由于靶体背侧仅是近似的绝热条件,导热反问题计算的靶体背侧温度略高于实测温度.结果表明,通过在靶体背侧增加绝热材料,即便采用单点测温,仍然可以很容易地获得足够精确的靶体温度和表面热流密度.     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.