Ti对中碳高锰钢奥氏体晶粒长大的影响

研究了Ti对中碳高锰钢在不同加热温度和保温时间下的奥氏体晶粒长大规律的影响。结果表明,随着加热温度的升高和保温时间的延长,含Ti钢的奥氏体晶粒长大速率明显较慢,且相同温度下其晶粒尺寸更为细小。含Ti钢中含有较多的纳米级Ti(C,N)粒子,Thermo-calc计算表明其完全固溶温度约1 450℃,当温度逐渐升高时,Ti(C,N)虽有部分固溶,但尺寸小于100 nm的粒子比例依然较高,起到了阻碍奥氏体晶界迁移的作用,因此高温下含Ti钢的奥氏体晶界迁移速率较慢。建立了含Ti钢的高温奥氏体晶粒长大模型:D_B=729.25t~(0.16)exp(-71 972.3/RT),根据拟合模型所得含Ti钢中的奥氏体晶界迁移能为72 k J/mol,大于不含Ti钢的45 k J/mol,同时生长指数n为0.16,而不含Ti钢为0.25,试验所得奥氏体晶粒尺寸与计算模拟值吻合较好。     

Effects of Lanthanum and Cerium on Acid Phosphatase Activities in Two Soils

To evaluate the security of using thulium, comparision between effects of La and those of Ce on acidic phosphatase activities in red soil and yellow soil in Zhejiang district was studied under conditions of ambient temperature and humidity. Results show that the acid phosphatase from different soil respondes to La and Ce differently. The activity of acid phosphatase in soil 1 declines with the increase of the concentration of La and Ce. The maximum inhibitory ratio of La and Ce reaches 69.8% and 71.0% respectively. But La and Ce have stimulative effect on the activity of acid phosphatase in soil 2.Under the effect of same concentration of the thulium, the acid phosphatase in two soils increases with the extending of culture time.     

Antibacterial Properties of Cerium-Bearing Stainless Steel Bearing Cerium

Antibacterial Properties of Cerium-Bearing Stainless Steel Bearing Cerium     

Effect of Lanthanum and Cerium on Expression of RSCU-PA-32k Gene in Saccharomyces Cerevisiae

Ｃｕｒｒｅｎｔｌｙｔｈｅｉｎｃｉｄｅｎｃｅａｎｄｌｅｔｈａｌｉｔｙｏｆｔｈｒｏｍｂｕｓｉｌｌｎｅｓｓａｒｅｖｅｒｙｈｉｇｈ ,ａｎｄｉｔｓｅｒｉｏｕｓｌｙｔｈｒｅａｔｅｎｓｐｕｂｌｉｃｈｅａｌｔｈ .Ｔｈｒｏｍｂｏｌｙｓｉｓｉｓｏｎｅｏｆｔｈｅｒｅｌａｔｉｖｅｌｙｅｆｆｅｃｔｉｖｅｍｅｔｈｏｄｓｔｏｔｒｅａｔｔｈｅｄｉｓ ｅａｓｅ .Ｓｉｎｇｌｅ ｃｈａｉｎｕｒｏｋｉｎａｓｅ ｔｙｐｅｐｌａｓｍｉｎｏｇｅｎａｃｔｉｖａｔｏｒ (ｓｃｕ ＰＡ 3 2ｋ )ｏｆｌｏｗｍｏｌｅｃｕｌａｒｗｅｉｇｈｔ(3 2ｋＤ)ｗａｓｄｉ…     

Cerium and Lanthanum Modified Pd/Al_2O_3 Catalysts for Methanol Decomposition

Ｍｅｔｈａｎｏｌｉｓｒｅｃｏｇｎｉｚｅｄａｓａｎａｌｔｅｒｎａｔｉｖｅｅｎｅｒｇｙｃａｒｒｉｅｒａｓｗｅｌｌａｓａｎｉｍｐｏｒｔａｎｔｃｈｅｍｉｃａｌｆｅｅｄｓｔｏｃｋ .ＴｏｉｎｃｒｅａｓｅｔｈｅｅｆｆｉｃｉｅｎｃｙｏｆｍｅｔｈａｎｏｌｆｕｅｌｅｄｖｅｈｉｃｌｅｓａｎｄｔｏｅｎａｂｌｅｔｈｅｕｓｅｏｆｍｅｔｈａｎｏｌｉｎＣ1ｂａｓｅｄｃｈｅｍｉｃａｌｉｎｄｕｓｔｒｙ ,ｄｅｃｏｍｐｏｓｉｔｉｏｎｏｆｍｅｔｈａｎｏｌｉｎｔｏＣＯａｎｄＨ2 ｉｓａｔｔｒａｃｔｉｖｅ ,ｐｒｅｆｅｒａｂｌｙａｔｌｏｗｔｅｍ…     

Toxic Effects of Lanthanum, Cerium, Chromium and Zinc on Potamogeton Malaianus

iththerapiddevelopmentofrareearthindustryandextensiveapplicationofrareearthinagriculture ,agreatmanyofrareearthelements (REEs)werere leasedintoenvironment ,especiallywaterenviron ment ,andtheconsequentseriousenvironmentpollu tionhasattractedpeople′satten…     

Existing Forms of Lanthanum in Purity Steels

Adding lanthanum to carbon-manganese purity steel, the existing forms of lanthanum were investigated. The results show that enrichment on grain boundary and solid solution in cementite are two kinds of important existing forms of lanthanum relating to micro-alloyed action. As a result of enrichment of lanthanum, the concentration of lanthanum aggregated on somewhere of grain boundary reaches as high as tens of times of its average content although the average content is very low. In addition, lanthanum atoms can replace partial Fe atoms that constitute cementite to form alloyed cementite, the solid solution amount of lanthanum in alloyed cementite increases as the increase of its average content in purity steel.     

Study on Interaction between Lanthanum and Phosphor in Purity Steel

Using SEM and EDS some particles containing La and P were discovered in low oxygen and sulfur purity steel with lanthanum. In these particles low melting point elements such as As and Sb also were detected. According to the result of simulative calculation of segregation, it is shown that La and P enrich so strongly in the process of solidification that their concentrations can satisfy thermodynamic condition to forme LaP compound or meet the requirements to forme eutectic phase in the last stage of solidification. Therefore, the particles are concluded as LaP compound or eutectics, which exist on grain boundary mainly.     

Influences of Cerium and Carbide on Mechanical Properties of Steels

Ｉｔｗａｓｔｈｏｕｇｈｔｔｈａｔｔｈｅｒａｒｅｅａｒｔｈｓｗｅｒｅｎｏｔｃａｒｂｉｄｅｆｏｒｍｉｎｇｅｌｅｍｅｎｔｓｂａｓｅｄｏｎｔｈｅｆａｃｔｔｈａｔｔｈｅｒａｒｅｅａｒｔｈｓｒｅａｃｔｏｎｃａｒｂｏｎｉｎｓｔｅｅｌｓｉｍｉｌａｒｌｙｔｏｓｉｌｉｃｏｎ ,ｔｈｅｅｌｅｍｅｎｔｗｈｉｃｈｎｅｖｅｒｆｏｒｍｓｃａｒｂｉｄｅａｎｄｉｓｄｉｆｆｅｒｅｎｔｆｒｏｍｔｈｅｅｌｅ ｍｅｎｔｓｓｕｃｈａｓｃｈｒｏｍｉｕｍ ,ｍａｎｇａｎｅｓｅａｎｄｔｕｎｇ ｓｔｅｎｗｈｉｃｈｆｏｒｍｃａｒｂｉｄｅｓ .Ｍｏｒｅｏｖｅ…     

低碳耐材在连铸极低碳钢和纯净钢生产中的应用

主要介绍武钢第二炼钢厂在连铸极低碳钢和纯净钢时，为确保减少连铸过程中钢水增碳．开发和应用了低碳钢包砖、大包保护管以及中间包浸入式水口，并取得了良好的使用效果。     

Plasma Nitriding of 722M24 Steel with Pure Lanthanum, Cerium and Neodymium as Sputter Sources

Ｓｉｎｃｅｔｈｅｉｎｉｔｉａｌｒｅｐｏｒｔｉｎｔｈｅｅａｒｌｙ 1 980ｓｔｈａｔｒａｒｅｅａｒｔｈａｄｄｉｔｉｏｎｈａｓａｃａｔａｌｙｔｉｃｅｆｆｅｃｔｏｎｔｈｅｇａｓｃａｒｂｏｎｉｔｒｉｄｉｎｇｐｒｏｃｅｓｓｏｆｓｔｅｅｌｓ[1] ,ａｌａｒｇｅａｍｏｕｎｔｏｆｗｏｒｋｈａｓｂｅｅｎｃｏｎｄｕｃｔｅｄｔｏｉｎ ｖｅｓｔｉｇａｔｅｔｈｅｉｎｆｌｕｅｎｃｅｏｆｒａｒｅｅａｒｔｈａｄｄｉｔｉｏｎｓｏｎｖａｒｉｏｕｓｔｈｅｒｍｏｃｈｅｍｉｃａｌｐｒｏｃｅｓｓｅｓ[2～ 8] .Ｉｔｈａｓｂｅｅｎｅｓｔａｂｌｉｓｈｅ…     

高碳纯净钢生产工艺的研究与实践

鞍钢股份有限公司第一炼钢厂试验研究了高碳纯净钢的冶炼操作技术,对纯净钢的工艺过程控制进行全面分析后,确定了高碳纯净钢的冶炼技术要点。将采用该工艺生产的高碳纯净钢与其他钢厂同类钢种进行对比,结果表明,该工艺提高了高碳钢的纯净度和性能指标。     

Study on Aldol Condensation of HCHO and CH3 CHO over MgO Catalysts Modified by Lanthanum and Cerium

Aldol condensation of HCHO and CH3CHO over MgO, modified MgO and Al2O3 with rare earth oxides,was studied. The measurement of adsorption of pyrrole on catalysts by in-situ FT-IR and NH3 TPD indicated thatthe addition of elements La or Ce into MgO increased the acidity of the solid. In-situ FI‘-IR showed that the activation of - C = O in HCHO adsorbed on CeO-MgO and La2O3-MgO occurred. The measurement of catalytic activity implied that the modified catalysts can promote the formation of pentaerythritol, dipentaerthritol and tripentaerythritol.     

Effects of Rare Earth on Structure and Mechanical Properties of Clean BNbRE Steel

The effects of REinsteel include cleaning,mod-ifyinginclusions and alloying[1 ~4]. With the develop-ment of steel-making and continuous casting process-ing,the fluctuation range of the composition of steelwas mini mized ,the cleanliness of steel was i mpr…     

Influence of Cerium on Solidification Microstructure of M2 High Speed Steel

Ｏｖｅｒｔｈｅｐａｓｔｄｅｃａｄｅｓ,ｅｘｔｅｎｓｉｖｅｓｔｕｄｙｏｎｔｈｅａｄｄｉｔｉｏｎｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｉｎｔｏｈｉｇｈｓｐｅｅｄｓｔｅｅｌｈａｓｂｅｅｎｃａｒｒｉｅｄｏｕｔ,ａｎｄｔｈｅｒｅｓｕｌｔｓｓｈｏｗｔｈａｔｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｈａｖｅｆｏｌｌｏｗｉｎｇｉｎｆｌｕｅｎｃｅ[1～3]:ａｌｌｅｖｉａｔｉｎｇｔｈｅｓｅｇｒｅｇａｔｉｏｎｏｆｏｘｙｇｅｎ,ｓｕｌｐｈｕｒａｎｄｐｈｏｓｐｈｏｒｕｓａｌｏｎｇｇｒａｉｎｂｏｕｎｄａｒｉｅｓ;ｉｎｃｒｅａｓｉｎｇｔｈ…     

铈和磷对锰钢脆性的影响

利用冲击试验、扫描电镜、透射电镜、俄歇谱仪等方法,研究了铈和磷对含锰钢脆性转化温度的影响.结果表明,磷在奥氏体晶界偏聚提高了含锰钢脆性转化温度,加入铈可减轻磷的偏聚程度,从而降低了脆性转化温度.     

铈对Fe Cr Ni Nb Ti Al W合金持久寿命及晶界析出相的影响

 研究了稀土元素铈对铁基合金Fe Cr Ni Nb Ti Al W晶界析出相的数量、形貌、分布的影响及其与持久寿命的关系。结果表明：铈含量较低时，晶界析出相主要是大片状相及少量颗粒相；当铈含量增加时，晶界中颗粒相数量明显增加，片状相减少，且析出相分布较均匀，当铈含量过高时，晶界中析出大量片状相及颗粒相，且析出相总量增加。这些析出相的数量、形貌以及分布等特征的变化规律与合金持久寿命的变化规律一致。     

Study on Carbon Nanotubes Prepared from Catalytic Decomposition of CH4 over Lanthanum Containing Ni-Base Catalysts

A series of lanthanum containing Ni-base catalysts were prepared by citric acid complex method.Carbon nanotubes (CNT) were synthesized bY catalytic decomposing CH4 over these catalysts and characterized by XRD, TEM and TGA.It is found that the addition of lanthanum can not increase the yield of carbon nanotube, but can make the diameter of carbon nanotube thinner and even.The more the lanthanum addsr, the thinner the diameter of CNTs becomes.With the CNTs prepared on Ni-Mg catalyst, the CNTs prepared on Ni-La-Mg catalyst has better crystallinity and thermal stability.     

Effect of Surface Modification on Behaviors of Cerium Oxide Nanopowders

Study was made on the effect of surface modification on the behaviors of cerium oxide nanopowders.A surfactant-sodium dodecyl sulfate（C12H25SO4Na）was used to modify the surface of CeO2 powder particles.The unmodified and modified CeO2 powders were characterized by using a powder comprehensive characteristic tester,laser particle size analyzer,specific surface area tester,X-ray diffraction tester,and a scanning electron microscope.The testing and analysis results showed that C12H25SO4Na surface modification might increase the flowability and dispersity,and decrease the specific surface area and agglomeration of CeO2 powders.The mechanism of the surface modification of CeO2 powder particles was also discussed.     

中碳锰钢用结晶器保护渣的分析研究

通过对中碳锰钢钢种特点及其对保护渣要求的深刻剖析,结合包钢的生产实际,对方、圆坯中碳锰钢生产所用保护渣的使用性能和理化性能进行了综合分析研究.