3％无取向硅钢薄板的表面纳米化结构与性能

为了探索金属薄板表面纳米化制备方法,本工作选取3％无取向硅钢热轧板进行表面机械研磨处理(SMAT)和异步轧制(CSR),研究深度方向结构和硬度的变化.结果表明:SMAT过程中,3％无取向硅钢通过位错的演变,在表面形成了等轴状、尺寸约为10 nm的、取向呈随机分布的纳米晶,纳米晶层厚度约为20 μm; SMAT样品经过C...     

冷轧IF钢表面纳米化后的组织与性能

利用机械研磨处理（SMAT）在冷轧IF钢表面制备出具有纳米晶体结构特征的表面层．利用金相观察和透射电镜分析研究了表面纳米层的结构特征,测定了硬度沿厚度的变化,并分析了表面纳米化（SNC）对力学性能的影响．结果表明：（1）表面机械研磨处理后,冷轧（CR）IF钢表面形成了平均晶粒尺寸为7～9nm、晶粒取向呈随机分布的纳米晶组织;（2）表面层附近的硬度显著提高;（3）纳米表层的存在使得材料强化的同时成形极限也得到提高．     

表面纳米化工业纯钛组织性能研究

采用表面机械研磨处理(SMAT)实现工业纯钛的表面纳米化,利用金相显微镜(OM)、显微硬度计对其微观组织及显微硬度进行表征、测定;利用动电位极化曲线和电化学阻抗谱(EIS),结合X射线光电子能谱分析(XPS)技术,研究了表面纳米化工业纯钛在Hank's人工模拟体液中的腐蚀行为。结果表明:SMAT处理工业纯钛表层晶粒尺寸达到纳米级,从表层到基体晶粒尺寸由小到大呈梯度分布,其表层显微硬度明显提高,并由表层逐步降低至基体硬度。SMAT处理工业纯钛的自腐蚀电位较原始工业纯钛正移,腐蚀电流密度较原始工业纯钛低,其EIS高频容抗弧半径较原始试样大,表现出更稳定的钝化现象。表面纳米化过程中产生的高密度晶界和位错为Ti~(4+)提供了更多的扩散通道,有助于表面产生稳定的保护钝化膜,提高其耐蚀性。XPS分析结果表明,SMAT处理工业纯钛钝化膜的主要成分为Ti O_2。     

表面纳米化316L不锈钢在酸性介质中腐蚀性能的研究

采用表面机械研磨处理(SMAT)在316L不锈钢上制备出纳米结构表层,研究表层纳米化组织的腐蚀性能. 结果表明:经过60 min SMAT后,样品表面形成了一定厚度的纳米表层.显微组织. 由晶粒尺寸为10～30 nm的双相组织(马氏体和奥氏体)组成. 表层腐蚀性能在c(H2SO4)=0.05 mol/L和c(Na2SO4)=0.25 mol/L构成的腐蚀介质中下降.     

无取向硅钢表面纳米结构的渗硅行为

 对3%无取向硅钢进行表面机械研磨处理（SMAT）,获得表面纳米结构,再进行550~650℃、4h固体粉末渗硅处理,用透射电镜（TEM）、扫描电镜（SEM）和X射线衍射仪（XRD）研究表层组织演变。结果表明：经过SMAT后,3%无取向硅钢表面晶粒尺寸降低至10nm左右,纳米晶层厚度约为20μm。经过550~650℃、4h渗硅处理后,SMAT样品表面形成化合物层,其厚度随着渗硅温度的升高由27μm增加到150μm。化合物层由FeSi和Fe3Si两相组成,其中FeSi相随着渗硅温度的升高而逐渐增加。     

BOF-LF-CSP工艺生产低碳热轧薄板的组织变化规律

为了弄清BOF-LF-CSP工艺生产低碳钢的组织变化规律,对低碳钢SS400进行了铸态组织、第一轧制道次的形变组织以及成品板卷的组织测试与分析.结果表明：薄板坯铸态组织为较细的枝状晶,铸坯表面层和中心差别很小.经第一道次大压下变形后板坯的晶粒组织得到明显细化,表面至中心区域的晶粒尺寸及硬度存在梯度分布.低碳钢SS400成品薄板的组织很细,平均晶粒尺寸在5μm左右.     

表面纳米晶化处理中碳钢的组织与力学性能

采用高能表面处理技术在40Cr钢的表面制备出具有纳米晶体特征的表面层.用扫描电子显微镜和透射电子显微镜研究了表面纳米层的微观结构,并利用纳米压入法测定了表面纳米层的硬度.结果表明,经过高能表面处理后,样品表面层的晶粒细化为纳米晶,平均晶粒尺寸约为11 nm,表面纳米层的硬度明显提高.     

表面机械研磨工业纯钛表面纳米化研究

表面机械研磨处理可以使工业纯钛形成纳米表面层, 通过扫描电镜、透射电镜和高分辨电镜观察SMAT处理后的工业纯钛表层组织, 并研究了工业纯钛表面纳米化机制. 工业纯钛表面纳米化机制为: 孪晶的形成和孪晶的交割使得原始晶粒尺寸减小, 同时使晶格取向发生改变, 有利于位错滑移; 孪晶通过自身交割, 以及位错密度增加及其相互作用, 形成了细小的孪晶与胞状组织; 胞状组织转变为多边形亚晶; 亚晶不断吸收位错形成大角度晶界, 亚晶以及取向不同的细小孪晶逐渐转变为随机取向的纳米晶.     

CDC处理提高合金工具钢的耐磨性

对典型合金模具钢H13,Cr12MoV进行了CDC处理,用金相显微镜及扫描电子显微镜观察了渗碳层的组织,用X射线分析了碳化物的组成.结果表明Fe-Cr-C三元系合金在950℃时CDC处理的最佳碳势为1.2%,H13进行CDC处理后表层组织为马氏体加弥散分布的碳化物,碳化物主要为Cr7C3,尺寸在200～300 nm;CDC处理使H13合金的表面硬度提高了Hm500,硬化层厚度为550 μm,耐磨性优于氮化处理的H13合金.Cr12MoV合金CDC处理后表面细小碳化物数量明显增多,使材料的表面硬度提高Hm400,硬化层厚度为1000μm,实践证明,其使用寿命是常规淬火加回火处理的2倍以上.     

高能球磨和放电等离子体烧结制备超细WC-8Co硬质合金

以0 .8 1μm的WC粉和1.3 5 μm的Co粉为原料,采用高能球磨制备了粉末比表面积为6.82m2 ·g- 1 ,粉末粒度为5 9.4nm的WC 8Co混合粉末。将此纳米粉末采用放电等离子体烧结(SPS)制备了WC晶粒度为0 .5～0 .6μm、硬度为HRA93 .5的超细硬质合金。研究了SPS烧结温度和添加晶粒抑制剂对显微组织与HRA硬度的影响。     

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

正~~     

Zinc Production by Province in 2014

正~~     

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.