DBS—偶氮氯膦—Os（Ⅳ）——KBrO3催化光度法测定微量锇

Ｏｓ（Ⅳ）对酸性介质中溴酸钾氧化ＤＢＳ－偶氮氯膦的褪色反应有明显的催化作用。据此反应建立了微量锇的催化分光光度法，方法的检出限为０．０１μｇ／１０ｍｌ，ＯｓⅣ在０．０１￣０．２０μｇ／１０ｍｌ有良好的线性关系。反应在水相中进行，灵敏度高，简便快速，用于贵金属精矿中锇的测定，结果满意。     

DBS─偶氮氯膦─Os（Ⅳ）─KBrO_3催化光度法测定微量锇

Ｏｓ（Ⅳ）对酸性介质中溴酸钾氧化ＤＢＳ－偶氮氯磷的褪色反应有明显的催化作用。据此反应建立了微量锇的催化分光光度法，方法的检出限为０．０１μｇ／１０ｍｌ，Ｏｓ（Ⅳ）在０．０１～０．２０μｇ／１０ｍｌ有良好的线性关系。反应在水相中进行，灵敏度高，简便快速，用于贵金属精矿中锇的测定，结果满意。     

阻抑动力学法测定铈的新指示反应研究——Ce(Ⅲ)-H_2O_2-水扬基荧光酮体系

在碱性介质中,铈（Ⅲ）能显著地阻抑Ｈ２Ｏ２氧化水扬基荧光酮（ＳＡＦ）褪色的指示反应,研究表明该动力学反应对铈（Ⅲ）为一级,测得反应的表观活化能为２８．７５ｋＪ／ｍｏｌ。据此建立了测定痕量铈的动力学分析法,测定条件为ＳＡＦ：４．０×１０－５ｍｏｌ／ｌ,Ｈ２Ｏ２：０．０１０％,ＮａＯＨ：２．０×１０－２ｍｏｌ／ｌ,５０℃。线性测定范围０．０４μｇ／ｍｌ～０．４４μｇ／ｍｌ,方法检测限为０．０２μｇ／ｍｌ（Ｃｅ）。当溶液中的铈含量为０．１６μｇ／ｍｌ时,３～８倍量的轻稀土,５～１１倍量的重稀土和同倍量的铀和钍等不干扰测定。测定了按不同稀土矿的稀土元素配分合成的样品中的铈含量,结果满意。     

阻抑动力学法测定铈的新指示反应研究：Ce（Ⅲ）—H2O2—水杨？…

在碱性介质中,铈能显著地阻抑Ｈ２Ｏ２氧化水杨基荧光酮褪色的指示反应,研究表明该动力学反应对铈为一级,测得反应的表观活化能力为２８．７５ｋＪ／ｍｏｌ。据此建立了测定痕量的动力学分析法,测定条件为ＳＡＦ：４．０×１０＾－５ｍｏｌ／ｌ,Ｈ２Ｏ２;０．０１０％,ＮａＯＨ：２．０×１０＾－２ｍｏｌ／ｌ,５０℃,线性范围０．０４μｇ／ｍｌ－０．４４μｇ／ｍｌ,方法检测限为０．０２μｇ／ｍｌ。     

微量银的光化学共振散射光谱分析

在０．０４ｍｏｌ／Ｌ Ｈ２ＳＯ４－０．３％Ｔｒｉｔｏｎ－Ｘ介质中,Ａｇ（Ⅰ）被紫外光光还原形成银溶胶,于４５０ｎｍ处产生一灵敏的共振散射峰,Ａｇ浓度在０．１～４μｇ／ｍｌ与共振散射光强度呈良好线性关系,方法的检出限为０．０５μｇ／ｍｌ Ａｇ。实验结果表明,该法用于废水中银的测定具有简便、快速等特点。     

三氯偶氮氯膦－Ru（Ⅲ）－KIO_4体系催化分光光度法测定微量钌

在酸性介质中，微量Ｒｕ（Ⅲ）的存在对ＫＩＯ＿４氧化三氯偶氮氯膦的褪色反应有明显的催化作用。据此褪色反应建立了微量钌的催化光度分析法，方法的检出限为０．０２μｇ／１０ｍｌ，Ｒｕ（Ⅲ）在０．０２～０．３０μｇ／１０ｍｌ有良好的线性关系。反应在水相中进行，应用于贵金属精矿中钌的测定，结果满意。     

三氯偶氮氯膦—Ru（Ⅲ）—KIO4体系催化分光光度法测定微量钌

在酸性介质中，微量Ｒｕ（Ⅲ）的存在对ＫＩＯ４氧化三氯偶氮氯膦的褪色反庆有明显的催化作用。据此褪色反庆建立了微量钌的催化光度分析法，方法的检出限为０．０２μｇ／１０ｍｌ，Ｒｕ（Ⅲ）在０．０２－０．３０μｇ／１０ｍｌ良好的线性关系。反应在水相中进行，应用于属贵金属精矿中钌的测定，结果满意。     

抗癌药物碳铂中微量银的测定

在５％ＨＮＯ３介质中，用石墨炉原子吸收法测定抗癌药物碳铂中微量Ａｇ，检测范围为０￣０．２μｇ／ｍｌ，可测定０．０００ｘ￣０．００ｘ％含量的Ａｇ，测定误差±１０％。     

Pd—DBS—偶氮胂新显色体系的分光光度测定钛合金中微量钯

在较高酸度的Ｈ３ＰＯ４介质中钯与ＤＢＳ－偶氮胂的新显色反应有较高的选择性。钯含量在０～１０μｇ／１０ｍｌ符合比尔定律，ε６１０＝３．３７×４０＾４。提出不经分离，准确、快速测定钛合金中微量钯的方法。     

锌冶金铜渣中铅锌钢铁的连续分析方法研究

本文研讨了铜渣中铅锌钢铁一次溶解试样，分别进行络合滴定的测定方法。实验证明：试样经酸分解、沉淀、分离，在各自的缓冲介质中，以５ｇ／ＬＸＯ溶液０．１５ｍｌ，１００ｇ／ＬＳＳＡ溶液５ｍｌ和２ｇ／ＬＰＡＲ溶液０．２ｍｌ分别为指示剂，用ＥＤＴＡ进行络合滴定，方法简单、快速，结果准确、可靠，对批样的分析测定，结果较为满意。     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.     

Microstructures and Mechanical Properties of a Newly Developed Austenitic Heat Resistant Steel

The effect of heat treatment on the microstructures and mechanical properties of a newly developed austenitic heat resistant steel(named as T8 alloy) for ultra-supercritical applications have been studied. Results show that the main phases in the alloy after solution treatment are γ and primary MX. Subsequent aging treatment causes the precipitation of M_(23)C_6 carbides along the grain boundaries and a small number of nanoscale MX inside the grains. In addition, with increasing the aging temperature and time, the morphology of M_(23)C_6 carbides changes from semi-continuous chain to continuous network.Compared with a commercial HR3C alloy, T8 alloy has comparable tensile strength, but higher stress rupture strength. The dominant cracking mechanism of the alloy during tensile test at room temperature is transgranular, while at high temperature, intergranular cracking becomes the main cracking mode, which may be caused by the precipitation of continuous M_(23)C_6 carbides along the grain boundaries. Typical intergranular cracking is the dominant cracking mode of the alloy at all stress rupture tests.     

The 15th Global Foundry Sourcing Conference 2014held in Qingdao China

Organized by Suppliers China Co., Ltd and co-organized by the National Technical Committee 54 on Foundry of Standardization Administration of China, the 15th Global Foundry Sourcing Conference 2014 （hereinafter referred to as FSC 2014） was successfully held on Sep. 23rd in Grand Regency Hotel, Qingdao. More than 500 delegates from home and abroad attended this conference, including over 130 purchasers from 20 countries and 380 domestic and foreign suppliers.     

Secondary Recrystallization Behaviors of Grain-Oriented 6.5 wt% Silicon Steel Sheets Produced by Rolling and Nitriding Processes

By rolling and nitriding processes, 0.23- to 0.3-mm-thick grain-oriented 6.5 wt% silicon steel sheets were produced. The core losses of grain-oriented 6.5 wt% silicon steel at frequencies ranging from 400 Hz to 20 k Hz were lower than that of the grain-oriented 3 wt% silicon steel with the same thickness by 16.6–35.8%. The secondary recrystallization behavior was investigated by scanning electron microscopy, energy-dispersive spectroscopy, and electron backscattered diffraction. The results show that the secondary recrystallization in high-silicon steel sheets develops more completely as the nitrogen content increases after nitriding, secondary recrystallized grain sizes become larger, and the sharpness of Goss texture increases. Because more {110}116 grains in the subsurface and the central layer of the sheets have a lot of 20°–45° high-energy boundaries in addition to Goss grains, {110}116 can be the main component through selective growth during secondary recrystallization when the inhibitor quantity is not enough and inhibitor intensity is weaker. The increases in nitrogen content can increase the inhibitor intensity and hinder abnormal growth of a mount of {110}116 grains and therefore enhance the sharpness of Goss texture.     

Laser Cladded TiCN Coatings on the Surface of Titanium

Laser cladded coatings of TiCN were produced on the surface of titanium. To obtain the optimal techniques, several conditions were tested by varying the laser scanning rate. The choice of shielding gas was also studied. The cladded coatings were then evaluated from the surface mechanics point of view based on their microhardness. The microstructure of some interesting samples was investigated by optical micrographs (OM). The results showed that under the condition of fixed pulse frequency and pulse width, the laser scanning rate and the shielding gas are the main factors influencing the components of coatings. TiCN coatings were decompounded and oxidized during the cladding process in the condition of no shielding gas of N2. X-ray diffraction results indicated that the composite coatings composed of TiCN, TiC, Ti2N, and TiO2 were produced using appropriate techniques. The results indicated that the best condition in terms of the surface microhardness is obtained when the scanning rate is 1.5mm / s, the pulse frequency is 15Hz, the pulse width is 3.0ms, and N2 is chosen as the shielding gas. The microhardness of the composite coatings is about 1331kg · mm - 2, which is about 4 times that of the substrate. The optical micrographs indicated that the cladding zone is made up of TiCN, TiO2, and some interdendritic Ti, but the diffusion zone mainly consists of the dendrites phase, and the cladded depth is about 80?滋m, which is more than 2 times that of the laser nitrided sample. There were no microcracks or air bubbles in the cladded sample, which was cladded using the above optimal techniques.     

Microstructure and Mechanical Properties of X80 Pipeline Steel Joints by Friction Stir Welding Under Various Cooling Conditions

X80 pipeline steel plates were friction stir welded(FSW) under air, water, liquid CO_2 + water, and liquid CO_2 cooling conditions, producing defect-free welds. The microstructural evolution and mechanical properties of these FSW joints were studied. Coarse granular bainite was observed in the nugget zone(NZ) under air cooling, and lath bainite and lath martensite increased signifi cantly as the cooling medium temperature reduced. In particular, under the liquid CO_2 cooling condition, a dual phase structure of lath martensite and fi ne ferrite appeared in the NZ. Compared to the case under air cooling, a strong shear texture was identifi ed in the NZs under other rapid cooling conditions, because the partial deformation at elevated temperature was retained through higher cooling rates. Under liquid CO_2 cooling, the highest transverse tensile strength and elongation of the joint reached 92% and 82% of those of the basal metal(BM), respectively, due to the weak tempering softening. A maximum impact energy of up to 93% of that of the BM was obtained in the NZ under liquid CO_2 cooling, which was attributed to the operation of the dual phase of lath martensite and fi ne ferrite.     

INDUSTRY NEWS

China Securities News reported on March 21, 2014： Guangdong Hongtu Wuhan Die Casting Co., Ltd. （Wuhan Hongtu）, a wholly owned subsidiary of Guangdong Hongtu Technology （Holdings） Co., Ltd., held a groundbreaking ceremony recently. With the registered capital of 50 million Yuan, Wuhan Hongtu has a total land area of 100,000 square meters and a plant construction area of 72,000 square meters. It is expected to have a production capacity of about 30,000 tonnes of aluminum castings annually after it is put into production.     

Microstructure,Mechanical Properties and Corrosion Behavior of Extruded Mg–Zn–Ag Alloys with Single-Phase Structure

Mg–Zn–Ag alloys have been extensively studied in recent years for potential biodegradable implants due to their unique mechanical properties,biodegradability and biocompatibility.In the present study,Mg–3Zn-x Ag(wt%,x=0.2,0.5 and0.8)alloys with single-phase crystal structure were prepared by backward extrusion at 340°C.The addition of Ag element into Mg–3Zn slightly influences the ultimate tensile strength and microstructure,but the elongation firstly increases from12%to 19.8%and then decreases from 19.8%to 9.9%with the increment of Ag concentration.The tensile yield strength,ultimate tensile strength and elongation of Mg–3Zn–0.2Ag alloy reach up to 142,234 MPa and 19.8%,respectively,which are the best mechanical performance of Mg–Zn–Ag alloys in the present work.The extruded Mg–3Zn–0.2Ag alloy also possesses the best corrosion behavior with the corresponding corrosion rate of 3.2 mm/year in immersion test,which could be explained by the single-phase and uniformly distributed grain structure,and the fewer twinning.     

Growth Morphologies of a Binary Alloy with Low Anisotropy in Directional Solidification

Two new classes of growth morphologies, called doublons and seaweed, were simulated using a phase-field method. The evolution of doublon and seaweed morphologies was obtained in directional solidification. The influence of orientation and velocity on the growth morphology was investigated. It was indicated that doublons preferred growing with its crystallographic axis aligned with the heat flow direction. Seaweed, on the other hand, could be obtained by tilting the crystalline axis to 45°. Stable doublons could only exist in a range of velocity regime. Beyond this regime the patterns formed would be unstable. The simulation results agreed with the reported experimental results qualitatively.