萍安钢高线穿水冷却系统技术改造

针对萍安钢高线生产的盘螺屈服强度偏低及屈服平台不明显的问题,进行了摩根穿水系统改造。改进了中轧、预精轧、精轧的穿水阀,采用摩根6代穿水冷却系统、低压多段,隔段隔阀开启。优化了穿水冷却工艺参数和轧制工艺参数,盘螺的屈服强度稳定在430 MPa、抗拉强度稳定在600 MPa以上,并且减少了缺陷部位的剪切量,提高成材率约0.2%。     

提高HRB400热轧带肋钢筋性能实践

针对济钢生产的HRB400钢筋存在强度偏低、质量不稳定等问题进行调查分析，认为主要原因是碳当量偏低、终轧温度高、轧后冷却效果差及负偏差值过大等。通过采取适当调整化学成分、增加压缩比、降低开轧温度、控制终轧温度、强化穿水冷却等一系列改进措施，保证了HRB400钢筋质量稳定，扰托强度平均提高35MPa，屈服强度平均提高30MPa。     

345 MPa级表层超细晶普碳钢中厚板的工业试制

以充分挖掘材料潜力提高中厚板强度级别为目标,开展了普碳钢中厚板的表层组织超细化和心部组织细晶化控轧控冷工艺研究.在形变相变规律研究及实验室轧制工艺摸索的基础上,制定了现场轧制工艺.在首钢中厚板厂3500 mm轧机上,采用化学成分(质量分数,%)为0.13～0.16 C-0.20～0.25 Si-0.80～0.95 Mn-0.01～0.02 P-0.005～0.010 S的连铸坯,成功轧制出表层超细晶中厚钢板.25 mm厚钢板的表层铁索体晶粒度达到12级,中心铁素体晶粒度达到11级,屈服强度达到350～385MPa,抗拉强度达到470～500 MPa,同时保持25%以上的伸长率,完全满足国标GB/T1591-94中规定的Q345 MPa级钢的力学性能要求.本研究对于企业降低冶炼成本,同时提高中厚板产品强韧性具有重要意义.     

HRB335热轧带肋钢筋轧后双线穿水冷却技术的应用

针对轧机产量提高后冷床冷却能力不足的问题,安装了轧后棒材穿水冷却装置。生产结果表明,HRB335Φ16 mm热轧带肋钢筋(/%:0.20C、0.20～0.40Si、0.4～1.2Mn),原终轧速度10.5～11.0 m/s,钢材至冷床温度1020～1050℃,钢筋的屈服、抗拉强度和伸长率分别为342 MPa、520 MPa和16.5%;使用穿水系统后终轧速度提高至11.5～12.0 m/s,钢材至冷床的温度降至880～900℃,通过冷床后降至260℃,钢筋的屈服、抗拉强度和伸长率分别为360 MPa,556 MPa和16.9%,生产率提高3%～5%。     

新标准下热轧带肋钢筋生产工艺的分析

新标准实施后，为了探究热轧带肋钢筋最佳生产工艺，对广东省不同生产工艺的主要钢企生产的钢筋进行了研究。分析表明，采用穿水冷却工艺，试样的强度偏高、韧性偏低，金相组织不合格，部分试样反向弯曲及抗震性能不合格，说明该工艺已严重不符合新标准要求；采用加铬、钼合金化热轧工艺，试样间强度偏差较大，且反向弯曲性能不合格，说明工艺不易控制、产品质量不稳定；采用常规热轧工艺，试样屈服强度偏低，仅高出标准下限1～2 MPa，说明该工艺生产的钢筋强度不够；采用钒氮合金化热轧工艺，试样各项试验指标均良好，当钒质量分数为0.33%～0.36%、氮质量分数为0.022%～0.025%时，产品综合质量最佳。     

超快速冷却HRB500Ⅳ螺纹钢筋的生产

利用20MnSiNb钢，通过轧后穿水冷却工艺，使φ16㎜钢筋力学性能达到了HRB500钢筋要求。为今后500 MPa级螺纹钢筋生产,奠定了基础。试验认为钢筋强度增加，主要源于细晶强化和相变强化。     

方坯直轧工艺对钢筋组织和性能差异性的影响

方坯直轧工艺是棒线材轧制生产未来发展趋势,该工艺是指通过提高连铸机钢坯温度并将高温钢坯直接送入轧机进行轧制的新工艺。为了掌握方坯直轧工艺对HRB400钢筋组织和性能差异性的影响,运用有限元方法对方坯轧制过程进行模拟。研究了方坯直轧工艺对定尺长度为9 m的钢筋内各相体积分数及晶粒尺寸分布的影响,同时结合力学本构方程预测了钢筋的力学性能。结果表明,方坯直轧工艺生产的钢筋微观组织主要由铁素体、珠光体和微量贝氏体构成,其平均体积分数分别为61.4%、38.4%和0.2%,相比于传统热轧工艺,方坯直轧工艺可实现提高珠光体体积分数、降低铁素体体积分数的作用;方坯直轧工艺可使钢筋在轴向上的晶粒尺寸分布存在一定差异,钢筋头部、中部和尾部区域的晶粒尺寸平均值分别为7.4、7.9和8.5μm;另外,钢筋屈服强度的上限值和下限值分别为454和449 MPa,说明9 m的钢筋头尾屈服强度相差5 MPa,其力学差异性不可忽略。     

400MPa盘条钢筋性能异常原因分析及控制

针对昆钢400MPa盘条钢筋生产过程中出现的屈服强度及断后伸长率偏低、同卷盘条力学性能不稳定等问题,取样进行了化学成分、金相显微组织、断口形貌及夹杂物检验分析。结果表明:屈服强度及断后伸长率偏低的主要原因为试样金相显微组织出现8%～30%的粒状贝氏体,粒状贝氏体质量分数30%的试样断口形貌表现为脆性断裂,钢筋塑韧性差;同卷盘条力学性能不稳定的主要原因为冷却速度不同造成金相组织中贝氏体质量分数不同。针对上述情况,炼钢采取出钢全程底吹氩及渣洗工艺,轧钢采取降低精轧及吐丝温度(精轧入口温度控制为870～890℃、吐丝温度控制为840～870℃)、减弱斯太尔摩控冷强度、增加辊道速度等措施,消除了400MPa盘条钢筋性能异常情况。     

Ti微合金化技术在热轧带肋钢筋中的应用

无锡新三洲特钢有限公司通过实施钛微合金化生产工艺,代替了原有的成本较高的Nb+Ti复合微合金化工艺,充分发挥了Ti的沉淀、析出强化作用。经过Ti微合金化工艺生产的HRB400E热轧带肋钢筋具有良好的微观组织形态,晶粒度达到了11级以上,钢筋力学性能稳定.对于Φ18 mm HRB400E钢筋,Ti微合金化成品屈服强度与Nb+Ti微合金化成品相差不多,抗拉强度明显优于Nb+Ti微合金化成品.Φ18 mm HRB400E钢筋平均屈服强度达到438.5 MPa,平均抗拉强度为613.6 MPa;Φ25 mm HRB400E钢筋平均屈服强度达到455.0 MPa,平均抗拉强度为625.0 MPa.     

表层组织超细化轧制工艺在L245级管线钢板开发中的应用

采用表层组织超细化轧制工艺在首钢3 500 mm中厚板生产线上进行了L245管线钢板的批量试制.结果表明,采用这种特殊的控轧控冷工艺,普碳钢的化学成分可保证钢板的力学性能达到厚规格L245管线钢板的要求.试制钢板表层铁素体晶粒达到12级,中心部位10级,屈服强度达到300～365 MPa,抗拉强度达到430～480MPa,同时保持29%～35%的伸长率,-10℃夏比冲击功130 J以上,剪切面积85%以上.在几乎不增加冶金成本的前提下,试制钢板具有优良的强度、塑性配合,优良的低温韧性水平.     

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.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.