2009年12月30日稀土价格

2009年9月30日稀土价格报价产品：金属镧．氧化镧．金属铈．氧化铈．金属镨．氧化镨,金属钕．氧化钕,镨钕氧化物,镨钕合金,金属钐．氧化钐．氧化铕．金属钆,金属铽．氧化铽,金属镝．氧化镝．氧化铒．氧化钇．镨钕镝合金．金属钇。混合稀土金属．电池级混合稀土金属．富镧金属．富铈金属,镝铁合金等稀土金属价格。     

2009年9月30日稀土价格

2009年9月30日稀土价格报价产品：金属镧,氧化镧,金属铈．氧化铈,金属镨．氧化镨．金属钕．氧化钕．镨钕氧化物,镨钕合金,金属钐,氧化钐．氧化铕．金属钆,金属铽,氧化铽,金属镐．氧化镝,氧化铒,氧化钇,镨钕镝合金,金属钇。混合稀土金属,电池级混合稀土金属,富镧金属．富铈金属．镝铁合金等稀土金属价格。     

2009年6月26日稀土价格

2009年6月26日稀土价格报价产品：金属镧．氧化镧,金属铈,氧化铈．金属镨．氧化镨,金属钕．氧化钕,镨钕氧化物,镨钕合金．金属钐,氧化钐．氧化铕．金属钆,金属铽．氧化铽,金属镝．氧化镝．氧化铒,氧化钇,镨钕镝合金．金属钇。混合稀土金属,电池级混合稀土金属．富镧金属．富铈金属。镝铁合金等稀土金属价格。     

电池级稀土氧化物制备工艺的研究

南方中钇富铕混合稀土先后经Ｎｄ／Ｓｍ分组、Ｌａ／ＣｅＰｒ／Ｎｄ分离,分别得到镧铈镨钕、镧、铈镨富集物、钕;北方富铈氯化然土原料经Ｃｅ／Ｐｒ分组得到镧富休物;除去稀土中非稀土杂质,经沉淀、灼烧后制备多种优质稀土氧化物,混样调配,为火法电解生产电池级稀土金属提供原料。     

2009年3月23日稀土价格

2009年3月23日稀土价格,报价产品：金属镧,氧化镧,金属铈,氧化铈,金属镨,氧化镨,金属钕,氧化钕,镨钕氧化物,镨钕合金,金属钐,氧化钐,氧化铕,金属钆,金属铽,氧化铽,金属镝,氧化镝,氧化铒,氧化钇,镨钕镝合金,金属钇,混合稀土金属,电池级混合稀土金属,富镧金属,富铈金属,镝铁合金。     

ICP—AES法测定La—Nd合金中稀土配分

研究了ICP－AES法测定镧,铈,镨、钕混合稀土金属中的稀土配分,分析结果准确,可靠。     

电感耦合等离子体原子发射光谱法测定铝硅活塞合金中镧铈镨钕钇

采用硝酸和氢氟酸溶解样品,高氯酸冒烟赶氟避免生成氟化稀土沉淀,选择La 333.749nm、Ce 456.236nm、Pr 417.939nm、Nd 406.109nm及Y 371.030nm作为分析线,扣除背景点消除基体干扰,运用干扰系数法克服谱线间干扰,通过基体匹配法配制标准溶液系列消除基体效应的影响,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定铝硅活塞合金中镧、铈、镨、钕和钇。结果表明:镧、铈的测定范围在0.01%~2.00%,镨、钕、钇的测定范围在0.005%~2.00%,校准曲线线性相关系数不小于0.9998。方法中各元素检出限为0.0003%~0.0018%。实验方法用于测定稀土铝合金合成试样中镧、铈、镨、钕和钇,结果的相对标准偏差(RSD,n=6)在0.50%~2.4%之间,加标回收率在94%~105%之间。实验方法用于含有稀土的铝合金标准样品中镧、铈、镨、钕和钇的测定,结果与电感耦合等离子体质谱法(ICP-MS)测定值相吻合,测定的稀土总量RE与认定值也相吻合。     

电感耦合等离子体原子发射光谱法测定电池级混合稀土金属中稀土配分和非稀土杂质

盐酸溶解样品后,将稀土配分镧、铈、镨、钕和非稀土杂质铁、硅、锌、镁配制成混合标准溶液系列并绘制校准曲线,保持标准溶液系列中稀土总量与试液中稀土总量一致以消除基体效应,采用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定电池级混合稀土金属中稀土配分镧、铈、镨、钕和非稀土杂质铁、硅、锌、镁。进行了各元素分析谱线的选择,考察了稀土元素对非稀土杂质元素及非稀土杂质元素间的干扰情况。各元素校准曲线线性回归方程的相关系数均不小于0.998 8。按照实验方法测定合成样品中稀土配分镧、铈、镨、钕,测定结果与理论值一致,结果的相对标准偏差(RSD,n=11)不大于3.0%。非稀土杂质铁、硅、锌、镁的检出限为0.001 0%～0.002 8%(质量分数),测定下限为0.005 0%～0.014%(质量分数)。对低锌低镁电池极混合稀土金属样品中非稀土杂质进行测定,测定值与参考值一致,测定结果的相对标准偏差(RSD,n=11)为1.3%～9.0%。按照实验方法测定实际电池级混合稀土金属样品和富镧金属样品中稀土配分镧、铈、镨、钕和非稀土杂质铁、硅、锌、镁,测定值与其他分析方法的结果基本一致。     

滇南地区发现超大型离子吸附型稀土矿

正云南省核工业二○九地质大队在滇南地区发现了一个超大型的稀土金属风化壳型矿床,属于国内十分罕见的稀土资源类型。其特点是碱性正长岩风化后形成的以镧、铈、镨、钕、钇为主的风化壳轻稀土矿,并含有镓、铌、铷、钪等稀散元素,风化壳厚     

ICP-AES法测定镨钕氧化物及镨钕金属中的镧、铈、钐、钇、铝和硅量

重点研究了镨钕配分对测定镨钕中镧、铈、钐、钇、铝、硅量的影响。通过研究镨钕配分与其空白值之间的关系,采用一定校正方法,成功地用一套标样解决了不同镨钕配分试样中的镧、铈、钐、钇、铝和硅量的测定问题。方法简单易行,结果稳定可靠。与ICP-M S的对照结果令人满意。     

Corrosion Resistance of Reactive Element Aluminide Diffusion Coatings on a Nickel‐based Superalloy and an Austenitic Stainless Steel

Continuously cast aluminium alloy wires containing active elements such as yttrium, cerium, lanthanum or silicon were used as evaporation sources for ion vapour deposition on nickel‐based Inconel IN738 and stainless steel 310S substrate materials. The samples were subsequently diffusion heat‐treated to form protective corrosion resistant nickel aluminide and iron aluminide coatings. The coated alloy materials were exposed for prolonged periods to high temperature cyclic oxidation, molten sulphate, and molten carbonate environments to evaluate their resistance to hot oxidation. For IN738, the lanthanum‐modified aluminide coating provided good thermal cyclic oxidation performance while the cerium‐modified coating exhibited effective hot corrosion resistance in a molten sulphate environment. For 310S stainless steel, all of the modified aluminide coatings provided equally good corrosion protection when exposed to molten carbonate attack under an oxidizing atmosphere.     

Effect of Yttrium on Toughness of Weld Metal Deposited by TiO_2－CaO Type Electrode

ＥｆｆｅｃｔｏｆＹｔｔｒｉｕｍｏｎＴｏｕｇｈｎｅｓｓｏｆＷｅｌｄＭｅｔａｌＤｅｐｏｓｉｔｅｄｂｙＴｉＯ_２－ＣａＯＴｙｐｅＥｌｅｃｔｒｏｄｅ￥ＺｈａｎｇＺｈｉ；ＺｈａｎｇＷｅｎｙｕｅ；ＣｈｅｎｇＢａｎｇｇｕ；ＸｕＹｕｈｕａｎ；ＦｅｎｇＬｉｎｇｚｈｉ（?..     

纯镍压力管道的焊接及检验

纯镍材焊接时易引起焊缝金属和热影响区晶粒粗大,易产生热裂纹、气孔等缺陷,通过优化焊接工艺和焊后的检测手段可以保证其焊接质量,从而保证设备的安全运行。     

A study on cold cracking susceptibility in high strength steel fillet weld joints

Controlled thermal severity (CTS) test which simulates the conditions in a single-pass fillet welding was carried out to determine the suitable minimum preheating temperature for the cold-crack-free welding of high strength steel ASTM A 516-70. The dependence of this minimum preheating temperature on diffusible hydrogen contents in weld metal was clarified. Then, the effect of climatic conditions on cold cracking susceptibility as a function of diffusible hydrogen contents in weld metal was studied. It is found that the cold cracking susceptibility of high strength steel is primarily related to the microsturcture of the HAZ which, in turn, is related to the preheating temperature. A lower preheating level, which resulted in harder microstructure, led to increased susceptibility. Suitable minimum preheating temperature required to prevent cold cracking increased with the increase in diffusible hydrogen contents of weld metal as a function of climatic conditions.     

Effect of oxygen on hydrogen cracking in high-strength weld metal

The effect of oxygen content on the susceptibility of high-strength weld metal to hydrogen cracking is examined. Increasing oxygen content had a detrimental effect on the cracking susceptibility of weld metal containing a dψusible hydrogen content of 4.7 ppm. In weld metal containing a much lower dψusible hydrogen content (0.87 ppm), increasing weld metal oxygen content had no detrimental effect on hydrogen cracking susceptibility. These results are explained by a model which proposes that hydrogen cracking occurs when a critical oxide inclusion density promotes intergranular fracture at prior austenite grain boundaries and when a critical level of hydrogen is present in the weld metal. For the same level of hydrogen (moisture) contamination, high-strength weld metals containing oxygen contents greater than 200 ppm will be much more susceptible to hydrogen cracking than deposits made using inert gas-shielded or vacuum-operated welding processes. Formerly Visiting Scientist, Department of Metallurgy and Materials Science, University of Toronto     

Effect of oxygen on hydrogen cracking in high-strength weld metal

The effect of oxygen content on the susceptibility of high-strength weld metal to hydrogen cracking is examined. Increasing oxygen content had a detrimental effect on the cracking susceptibility of weld metal containing a dψusible hydrogen content of 4.7 ppm. In weld metal containing a much lower dψusible hydrogen content (0.87 ppm), increasing weld metal oxygen content had no detrimental effect on hydrogen cracking susceptibility. These results are explained by a model which proposes that hydrogen cracking occurs when a critical oxide inclusion density promotes intergranular fracture at prior austenite grain boundaries and when a critical level of hydrogen is present in the weld metal. For the same level of hydrogen (moisture) contamination, high-strength weld metals containing oxygen contents greater than 200 ppm will be much more susceptible to hydrogen cracking than deposits made using inert gas-shielded or vacuum-operated welding processes. Formerly Visiting Scientist, Department of Metallurgy and Materials Science, University of Toronto     

电感耦合等离子体原子发射光谱法测定赤泥浸出液中稀土元素

对赤泥浸出液中稀土元素含量进行测定可以指导研发人员初步判断赤泥中的稀土总量。采用5 mol/L盐酸浸取赤泥中稀土元素镧、铈、镨、钕、钪、钇,并采用电感耦合等离子体原子发射光谱法(ICP-AES)进行了测定。以功率、辅助气流量、分析泵速和积分时间为考察因素,各元素分析谱线的发射强度为考察指标,设计了L₉(3⁴)的正交试验,确定了电感耦合等离子体原子发射光谱仪的最佳工作条件为功率950 W、辅助气流量为0.50 L/min、分析泵速为100 r/min、积分时间为10 s。使用标准加入法绘制校准曲线,消除了基体及杂质元素对待测稀土元素测定的影响。各待测元素校准曲线的线性相关系数均不小于0.999 9,方法中稀土元素镧、铈、镨、钕、钪、钇的检出限在0.002 4～0.013 mg/L之间。按照实验方法测定赤泥浸出液实际样品中稀土元素镧、铈、镨、钕、钪、钇,结果的相对标准偏差(RSD,n=6)为0.21%～1.2%,回收率为96%～114%。采用实验方法和电感耦合等离子体质谱法(ICP-MS)分别对赤泥浸出液中的稀土元素镧、铈、镨、钕、钪、钇进行测定,两种方法的测定结果基本一致。     

On the weldability, composition, and hardness of pulsed and continuous Nd:YAG laser welds in aluminum alloys 6061,5456, and 5086

The effect of Nd:YAG laser welding aluminum alloys 6061, 5456, and 5086 was studied from a perspective of alloying element vaporization, hot cracking susceptibility, and resultant mechanical properties. Both continuous wave and pulsed Nd.YAG laser welds were investigated. It was found that Mg was vaporized during welding, the extent of which was a function of the weld travel speed. Calculations based upon evaporation theory, and assuming a regular solution model, resulted in an estimation of weld pool surface temperatures from 1080 to 1970 K for the continuous wave welds. Pulsed Nd:YAG laser welds were observed to be extremely susceptible to weld metal hot cracking whereas continuous wave Nd:YAG laser welds were crack-free. The hardness of 6061 welds was affected by the Mg vaporization such that base metal strengths could not be achieved by subsequent re-heat treatment to the T6 condition. This loss in hardness was attributed to a reduced ability of the alloy to precipitation harden due to a lower Mg concentration. In the cases of 5456 and 5086, when samples containing welds were processed to the O condition, the weld metal had reduced hardness relative to the base metal. This loss of hardness was also attributed to the loss of Mg in these welds, resulting in reduced solid solution strengthening.