薄板坯连铸连轧低温卷取生产双相钢的工业试验

在薄板坯连铸连轧生产线上,利用微合金元素Nb、Ti析出抑制再结晶发生,加工硬化奥氏体加速铁素体相变,轧后连续快速冷却至低温卷取,利用细晶强化和相变强化生产低成本高强度热轧双相钢。在FTSR生产线上进行工业试验。结果表明,在终轧800～820℃,快速冷却至卷取温度300℃以下,可以得到铁素体和马氏体双相组织,屈服强度400MPa以上,抗拉强度超过650MPa,屈强比低于0.70,伸长率大于20%。     

Nb对Q345系列钢板强韧性的影响

通过加入微合金元素Nb，发挥其在高温变形时推迟奥氏体的再结晶时间，提高奥氏体再结晶温度的作用，轧制工艺上采用控制轧制和控制冷却能有效提高Q345系列钢板的强韧性。采用再结晶控制轧制及非再结晶控制轧制等方法来控制钢板晶粒尺寸，细化晶粒，发挥细晶强化以及析出强化的作用，可以降低钢板的韧脆转变温度。试验结果显示，在钢中加入微合金元素Nb后，通过控制轧制控冷工艺，提高了Q345系列中厚钢板的强度，特别是50％FTT达到-73℃，与Q345B钢板相比降低了48℃。     

低合金冷轧高强钢HC340LA工艺优化生产实践

为解决HC340LA存在的屈服强度波动大且性能合格率低的问题,窄成分控制钢中的主要强化元素C、Mn、Nb,提高0.40～0.79 mm规格的卷取温度、退火温度,并适当降低运行带速,降低1.60～2.00 mm规格的卷取温度、退火温度,并适当提高运行带速,减少了屈服强度波动,使力学性能合格率得到了明显提升。统计了优化后正常生产的HC340LA的力学性能,屈服强度平均从375 MPa降低至364 MPa,波动范围从82 MPa降低至30 MPa,抗拉强度平均从483 MPa降低至476 MPa,伸长率平均在28%以上,力学性能合格率从98.8%提升至99.8%。     

控轧控冷工艺参数对Nb微合金化高碳钢组织的影响

在Gleeble-1500热／力模拟机上模拟了加热温度、变形温度和冷却速度对含Nb和不含Nb高碳钢组织的影响。试验结果表明，0．71％c钢含0．031％Nb时，原始奥氏体平均晶粒尺寸减少30μm左右，再加热粗化温度由1050℃提高至1175℃以上，变形奥氏体再结晶温度由800℃提高到900℃以上。     

Nb含量对GH4169合金组织和拉伸性能的影响

采用真空感应熔炼、锻造、轧制、热处理等工艺得到Nb元素含量分别为4.99%、5.13%、5.34%、5.50%的四种GH4169合金,研究了Nb元素含量对GH4169合金组织和拉伸性能的影响。结果表明:随着Nb元素含量的增加,GH4169合金两组室温屈服强度和抗拉强度的均值分别由1124.5 MPa和1402 MPa提高至1152.5 MPa和1489 MPa,两组650℃屈服强度和抗拉强度的均值分别由867.5 MPa和1035 MPa提高至975.0 MPa和1105 MPa,室温拉伸塑性略有降低,但650℃拉伸塑性几乎无变化,说明Nb元素含量的增加促进了主要强化相γ″的析出和长大,同时金相观察表明同样促进了晶界δ相的析出。     

Nb对C-Si-Mn-Cr双相钢相变规律、组织和性能的影响

  根据C Si Mn Cr和C Si Mn Cr Nb实验钢的相变规律,在实验室进行了控轧控冷实验研究,分析了微合金元素Nb对高强度热轧双相钢相变规律、组织和性能的影响。实验结果表明,Nb可显著推迟铁素体和珠光体转变,并显著降低铁素体开始转变温度,但对铁素体终止转变温度和贝氏体转变温度区间基本没有影响。经Nb微合金化后,实验钢的屈服强度和抗拉强度增幅均在100 MPa以上,屈服强度的增幅高于抗拉强度,且在强度大幅度升高的同时,伸长率下降并不明显,表明Nb的细晶强化作用对提高中温卷取热轧双相钢强度级别的效果明显。     

轧制温度制度对一种高强度耐候钢性能影响研究

采用添加Cu,Ni,Cr耐大气腐蚀元素并有效结合Nb,Ti,Mo等微合金元素的成分设计思路,结合控轧控冷技术研制开发了屈服强度达550 MPa的高强度低合金耐候钢.该铜种P含量极低,在保证优良耐大气腐蚀性能的同时有效地保证了焊接性.系统地研究了温度及轧制工艺对钢种综合性能的影响,结果表明合理控制加热温度制度、终轧温度工艺以及卷取工艺制度,能够保证在微观组织上形成超细化铁素体晶粒,通过细晶强化和析出强化等强化机制的结合,在大幅提高强度的同时,保证优异的低温冲击韧性.该钢种的耐大气腐蚀性能与传统耐候钢相当,满足国家相关行业标准要求.     

铌对低碳钢形变板条马氏体组织再结晶的影响

研究了0．05％C-0．12％Nb钢板1200℃固溶，10％冰盐水处理-15％冷轧变形600～680℃时效时Nb对钢中板条马氏体再结晶行为的影响。试验结果得出在600～680℃范围内，Nb能阻止变形马氏体组织的再结晶，时效组织主要为保持板条马氏体位向的回火索氏体，未发现粒状铁素体。该钢在固溶处理 15％冷变形 640℃时效后的屈服强度为712．5MPa，抗拉强度740．0MPa，延伸率邀19．5％，而该钢经固溶处理 640℃时效后的屈服强度为490．0MPa，抗拉强度562．5MPa，延伸率δs22．5％，发现未经15％冷轧变形的0．05％C-0．12％Nb钢在时效过程板条马氏体组织发生明显的相变再结晶，表明时效过程变形能促进Nb的碳氮化物弥散析出，阻止板条-马氏体相变再结晶，从而提高钢的强度。     

采用控轧控冷工艺生产车轮用轮辐钢板

通过1700 mm热连轧机组对轮辐钢(%:0.09C、0.12Si、0.98Mn、0.010P、0.005S、0.010Nb、0.04Als)进行830～890℃终轧温度和620～680℃卷取温度的轧制试验。结果表明,板坯加热温度1230～1250℃、终轧温度(870±15)℃、卷取温度(660±15)℃生产的车轮用轮辐钢板的组织为细铁素体加少量的珠光体,屈服强度335～380 MPa,抗拉强度430～485 MPa,伸长率26%～31%,每卷带钢的纵向强度差为13～37 MPa,在车轮制作过程中冲压成型良好,冲废率小于0.3%。     

控轧控冷工艺对B510L组织性能的影响

对B510L采用不同形变热处理工艺进行了实验,分析了加热温度、终轧温度和卷取温度对实验钢力学性能和微观组织的影响.结合加热温度对合金元素Nb的作用机理进行了探讨,分析了贝氏体对带钢性能的影响.提出了适合工厂试生产的工艺制度为:加热温度1200℃保温2～3h;终轧温度780～800℃,精轧压下量>80％;卷取温度400℃左右.     

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.