RE／S值对控轧低碳Mn—Nb—RE钢硫化物成分和形貌的影响

用扫描电测定了含０．０４１％－０．０７６％ＲＥ的低碳Ｍｎ－Ｎｂ－ＲＥ钢中硫化物的成分，大小和形貌。ＲＥ／Ｓ值为２．８－３．０时，钢中的硫化物充分变质。     

稀土对热浸Al－3Si合金镀层影响的研究

本文对在Ａｌ─３Ｓｉ合金浴中加入０．０５～０．７９％ＲＥ后获得的热浸铝合金镀层的组织和耐腐蚀性性能进行了研究。研究结果表明，微量（≤０．３５％）ＲＥ能改善铝合金浴的流动性和镀层与钢基的结合，并提高镀层的耐盐雾腐蚀和耐３％ＮａＣｌ盐水浸泡腐蚀性能；而过量ＲＥ则由于在镀层中形成明显的ＲＥ富集区而降低镀层的耐腐蚀性能。     

控轧14MnNRE钢中非金属夹杂物的扫描电镜研究

本文利用扫描电子显微镜对控轧１４ＭｎＮｂＲＥ钢非金属夹杂物进行了观察，并利用能谱仪分析了非金属夹杂物的化学成分。含有０．０５４％ＲＥ的１４ＭｎＮｂＲＥ钢中的硫化物主要是细小球状的稀土元素硫化物ＲＥ２Ｓ３，尚存的少量条状ＭｎＳ型夹杂物也变得小而短。     

RE—Ca对ZG35CrMo铸钢塑韧性的影响

用光学、扫描电子显微镜、Ｘ－射线衍射和电子探针微区分析了ＺＧ３５ＣｒＭｏ铸钢的显微组织、非金属夹杂物和断口形貌。试验结果表明，ＺＧ３５ＣｒＭｏ铸钢经适量ＲＥ－Ｃａ处理，可消除魏氏组织，细化晶粒，钢中夹杂物由多角状变为球状，其数量减少，分布均匀，明显提高了铸钢的塑韧性和强度。     

ICP－AES法测定矿渣中痕量金

ＩＣＰ－ＡＥＳ法测定矿渣中痕量金。称样５．００００ｇ于６５０℃灼烧后，用王水溶解，滤液通过ＴＢＰ萃取树脂色谱柱吸附，０．１ｍｏｌ／ＬＨＣｌ＋０．１ｍｏｌ／Ｌ硫脲混合淋洗液解脱。本法分析０．０５１ｇ／ｔ含量的金标样，结果与推荐值吻合。六次分析结果的相对标准偏差（ＲＳＤ）＜５％。回收率为９６％～１０４％。方法简便，快速和准确。     

2－（3，5－二氯－2－吡啶偶氮）－5－二甲氨基苯胺作为铜的络合滴定指示剂的研究

研究了２－（３－５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺作为钢的络合滴定新指示剂。结果表明,试剂能在ｐＨ３．０～６．５时以ＥＤＴＡ滴定铜,终点由紫色突变为黄色（铜量多时为绿色）。终点变化敏锐,准确度高,比ＰＡＮ、ＰＡＲ等优越。该法可用于矿石中铜的测定。     

控轧控冷工艺对低碳Mn－Nb－Cu－RE钢力学性能的影响

对不同碳当量的低碳Ｍｎ－Ｎｂ－Ｃｕ－ＲＥ钢板进行了控制轧制和控制冷却试验；研究了控轧控冷工艺参数对力学性能、铁素体晶粒平均直径和沉淀相微细颗粒平均直径的影响；探讨了降低终轧温度和增加冷却速度对低碳Ｍｎ－Ｎｂ－Ｃｕ－ＲＥ钢的强化作用机制。     

ICP—AES法测定钢中全铝

本文采用ＩＣＰ－ＡＥＳ法测定钢中合铝，讨论了碱金属离子对ＩＣＰ光谱仪工作的影响及其人他各种光谱线干扰和化学干扰，通过实验确定仪器的最佳工作条件，取得较好的精度和重现性，此法测定范围为０．００２％～０．５％。     

气压烧结Re—α＼β—Sialon陶瓷材料

选用Ｓｉ３Ｎ４，ＡｌＮ，Ａｌ２Ｏ３和Ｓｎ２Ｏ３（或Ｎｄ２Ｏ３）粉末为原料，在１８００～１９５０℃的温度范围内，１．０～３．０ＭＰａ氮气压力下烧吉（ＧＰＳ），制备了性能优良的Ｒｅ－α／β－Ｓｉａｌｏｎ（Ｒｅ＝Ｎｄ，Ｓｍ）陶瓷材料，利用ＸＲＤ，ＥＤＳ，ＴＥＭ和ＥＲＥＭ手段研究了材料的相组成，显微结构特性与其性能的关系。结果表明，其主晶相为长柱状的β－Ｓｉｌａｏｎ和近似等轴的Ｒｅ－α－Ｓｉａｌｏｎ，晶界     

P_（507）（煤油）／（Sm－Eu－Gd）Cl_3（EuCl_2）－HCl体

本文在选定的工艺条件下，在振动筛板柱中研究了Ｐ（５０７）（煤油）／（Ｓｍ－Ｅｕ－Ｇｄ）Ｃｌ３（ＥｕＣｌ２）－ＨＣｌ体系的两相流动特性和传质特性。结果表明，该体系在振动柱中有良好的流动特性。在流比２．５～４．０，振幅＝１０ｍｍ，频率＝３００～３５０ｍｉｎ（－１）条件下，两相总液泛通量达２２０Ｌ／ｄｍ２·ｈ，存留分数一般为１２～１５％。用分段近似计算法，估算了柱子的传质效率。对于较难萃取的组分Ｓｍ，平均传质单元高度为０．５２ｍ，平均理论级当量高度为１．８２ｍ。     

Kinetics of Formation of Large-Dimension Rare Earth Inclusion in Steels

The elemental distribution within the large-dimension rare earth inclusion in steels was studied through analysis on plane distribution of elements by EPMA (Electron Probe Microanalyzer). The kinetics and mechanism of formation of RE inclusion were discussed, taking 5CrNiMo steel with the addition of RE and other microalloying elements as example. RE inclusions nucleate on oxides and sulphides with high melting point and grow up separately, then integrated by relatively high surface activity, which is a particular characteristic of RE elements, in liquid phase and during the course of solidification. Finally, the fine and dispersed RE inclusions merge and grow into a large-dimension one.     

Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel

The types,morphologies and distributions of nonmetallic inclusions in Cu-P weathering steels with and without rare earth were analyzed through a quantitative image analyzer,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)attached to SEM.Solid-soluble content of rare earth in the steels was analyzed by non-aqua electroanalysis and ICP.The results showed that rare earth modified the types and the morphologies of inclusions in the weathering steels.The small spherical rare earth oxysulfides and rare earth sulphides replaced the elongated MnS inclusions in the RE weathering steels.The rare earth inclusions dispersedly distributed and most inclusions were smaller than 2 μm in size.The optimum content of RE was 0.0065%-0.016% for 10PCuRE weathering steels containing about0.002% oxygen and 0.004% sulfur.Solid-soluble content of rare earth in steels was(14-20)x 10-6,which can act as a micro-alloying element.The corrosion resistance of 10PCuRE weathering steels and Q235 were studied by dry-wet cyclic immersion test.Their corrosion rates were obtained respectively.The polarization curves and pitting corrosion behaviors of weathering steels with and without rare earth were measured by electrochemical methods.The corrosion resistance of Cu-P weathering steels was improved by adding an appropriate amount of rare earth.Less and fewer rare earth inclusions largely decreased pitting susceptibility and rate of pit propagation.The pitting potential and the resistance against pitting corrosion of the RE weathering steel were significantly improved due to the modification of rare earth to inclusions.     

Microstructure of Steel 5Cr21Mn9Ni4N Alloyed by Rare Earth

The microstructure, composition and shape of precipitated phase under as-cast and finished product state of 5Cr21Mn9Ni4N steel with different rare earth （RE） amount were studied. Mechanical properties of 5Cr21Mn9Ni4N steels withont RE addition and with RE added by 0. 2% in mass percent were tested respectively. The results indicate that the solid solution amount of RE is about 10^-6 -10^-5 order of magnitude in 5Cr21Mn9Ni4N steel. Dendrite of as-cast condition is refined obviously and dimension of interstitial phase is shortened when RE is added by 0.10%-0.20%. But the microstructure will be coarser if surplus RE is added. Precipitated phase under finished product state distributes evenly in nearly same size with RE added by 0. 2% which leads to a largely improved high temperature mechanical property.     

稀土对42CrMoTiB钢夹杂物和力学性能的影响

试验42CrMoTiB钢和稀土微合金化42CrMoTiBRE钢(/%:0.41～0.43C、0.36～0.38Si、0.59～0.72Mn、0.018～0.020P、0.005～0.010S、1.08～1.13Cr、0.16～0.19Mo、0.06～0.08Ti、0.003～0.004B、0～0.020Ce或Sm,0.001 3～0.001 5T[O])由150 kg真空感应炉冶炼,浇铸成平均断面尺寸165 mm×165 mm的钢锭,锻成120mm×120 mm钢坯。研究了Ce或Sm对42CrMoTiB钢锻坯夹杂物和力学性能的影响。结果表明,与未加稀土42CrMoTiB钢相比,加入0.18RE后(钢中RE含量0.019%～0.020%)42CrMoTiBRE钢中的夹杂物含量大幅降低,A类、B类和D类粗系夹杂级别分别由0.5、2.0和0.5降低至0、0～0.5和0,细系夹杂分别由0.5、1.5和2.0降低至0、1.0和1.0。加入RE改变了钢中夹杂物形貌,形成球形稀土硫氧化物;加稀土明显提高钢的塑性和韧性,与42CrMoTiB钢相比42CrMoTiBCe钢横向断面收缩率(Z)和夏比冲击功(A_KV)分别由22%和17 J/cm²提高至30%和28 J/cm²。      

稀土对球墨铸铁中共存As、Sn、Pb、Ti的中和作用

全部采用龙岩生铁，制取球墨铸铁。球化剂为镁硅铁合金，同时分别添加０．００％、０．０１％、０．０２％、０．０３％、０．０４％、０．０５％、０．０７％稀土硅铁合金进行球化处理。结果表明，稀土不能完全消除与中和高含量微量元素共存对石墨球化的干扰作用。但适量稀土可部分中和微量元素、促进形核、改善球状石墨的表面形貌。削弱微量元素的有害作用。     

Effects and Mechanisms of RE on Impact Toughness and Fracture Toughness of Clean Heavy Rail Steel

 Clean high carbon heavy rail steel was prepared by the process of vacuum induction furnace smelting, forging and rolling. Mechanisms of RE on the impact toughness and fracture toughness for clean high carbon steel were investigated. In addition, the appropriate range of RE content for clean high carbon steel was determined. Both the austenite grain size and pearlite lamellar spacing decreased due to small amount of RE, consequently the impact toughness and fracture toughness were improved evidently. When the RE content exceeded a critical value, the pearlite lamellar spacing was increased, because RE was segregated on the austenite grain boundaries, damaged the orientation relationship of pearlite transformation, caused the disorder growth and morphology degenerating of pearlite. With the increasing of RE content, both the impact toughness and fracture toughness of clean high carbon steel were gradually increased at first and then decreased. It was found that when the RE content was between 00081% and 00088%, both the impact toughness and fracture toughness of clean high carbon heavy rail steel were the best. The maximum ballistic work was 212 J (20 ℃) and 122 J (-20 ℃), respectively. The maximum plane-strain fracture toughness was 4567 MPa·m1/2 (20 ℃) and 3704 MPa·m1/2 (-20 ℃), respectively.     

大洋多金属硫化物冶炼性能研究

主要针对我国多金属硫化物勘探合同区样品产出的精矿开展冶炼工艺方案研究，考察其冶金性能，综合回收其有价金属。通过试验研究，富锌多金属硫化物精矿经焙烧-酸浸后，锌和铜浸出率可分别达到99.22%和96.71%，贵金属主要富集于浸出渣中，为我国大洋多金属硫化物的冶金技术开发提供依据。     

Effect of rare earths on corrosion resistance of Cu-30Ni alloys in simulated seawater

Cu-30Ni-xRE(x=0-0.213 wt.%) alloy was prepared by adding rare earths(RE) in melted Cu-30Ni alloy using metal mould casting method.The effects of RE on corrosion resistance of the alloy in simulated seawater were investigated using optical microscope,scanning electronic microscope with energy-dispersive spectrometer and electrochemical measurement system.The results showed that the corrosion resistance of Cu-30Ni alloy was greatly improved by adding proper amount of RE,whereas excess addition of RE worsened ...     

Influence of rare earth nanoparticles and inoculants on performance and microstructure of high chromium cast iron

The high chromium cast irons (HCCIs) with rare earth (RE) nanoparticles or inoculants were fabricated in the casting process. The phase compositions and microstructure were analyzed by X-ray diffraction (XRD) and optical microscopy (OM), respectively. The hardness and impact toughness were tested by Rockwel-hardmeter and impacting test enginery. And then, the morphology of fracture was researched by scanning electron microscopy (SEM). The results demonstrated that the phase compositions of HCCIs with addition of RE nanoparticles or inoculants which were M7C3 carbides + α-Fe did not change obviously. However, the prime M7C3 carbides morphology had great changes with the increase of RE nanoparticles, which changed from long lath to granular or island shape. When the content of RE nanoparticles was 0.4 wt.%, the microstructure of high chromium cast iron was refined greatly. The microstructure of carbides was coarser when the addition of RE nanoparticles was higher than 0.4 wt.%. The hardness and impact toughness of HCCIs were improved by addition of RE nanoparticles or inoculants. The impact toughness of HCCIs was increased 36.4% with RE nanoparticles of 0.4 wt.%, but the hardness changed slightly. In addition, the adding of RE nanoparticles or inoculants could reduce the degree of the brittle fracture. Fracture never seemed regular, instead, containing lots of laminates and dimples with the increase of the RE nanoparticles. The results also indicated that the optimal addition amount of the RE nanoparticles was 0.4%, under this composition, the microstructure and mechanical property achieved the best cooperation. In addition, through the study of erosion wear rate, when adding 0.4% RE nanoparticles into the HCCIs, the erosion wear rate got the minimum 0.32×10-3 g/mm2, which could increase 51.5% compared with that without any RE nanoparticles.     

稀土对X70管线钢腐蚀行为的影响

试验用X70管线钢(/%:0.12C、0.20Si、1.60Mn、0.005P、0.005S、0.10V、0.10Nb、0～0.15RE)用10kg真空感应炉冶炼。采用电化学和失重分析法研究了微量稀土对X70管线钢在0.1 mol/L Na₂SO₄水溶液中的腐蚀行为。试验结果表明,微量稀土可降低管线钢腐蚀电流i_corr,改善腐蚀形貌。随着稀土加入量的增加,腐蚀电流减小,当钢中的RE含量由0增加至0.10%时腐蚀速率由7.43μg/(cm².day)降至0.29μg/(cm².day)。稀土的最适宜加入量是0.10%。