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Liu P.-H.,CAS Hefei Institutes of Physical Science | Liu P.-H.,Hefei University of Technology | Mao Z.-H.,CAS Hefei Institutes of Physical Science | Mao Z.-H.,Hefei University of Technology | And 8 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2017

The China fusion engineering test reactor is a new tokamak device. It is a commercial reactor, which demands a superconducting magnet with higher magnetic field. The maximum field of CS and TF will get around 15 T, which is much higher than that of present reactors. In order tomeet the requirements, the new conductorwith Bi2 Sr2CaCu2Ox is considered as one potential material for the superconducting magnets. Because Bi2212 wire needs to endure special heat treatment with oxygen, the jacket material is one key issue. As one new material, Ni80Cr has an excellent performance, which cannot react with Bi-2212 wire. It could be one potentialmaterial as Bi-2212 cable-in-conduit conductor jacket. In order to understand themechanical properties of Ni80Cr, the samples with different conditions were prepared, and tested at high, room, and low temperature (4.2 K). The results are analyzed in this paper. © 2017 IEEE.

Li H.,Shanghai University | Li H.,Zhejiang Jiuli Hi Technology Metals Co. | Wang B.,Shanghai University | Wang B.,Guiyang Vocational and Technical College | And 6 more authors.
Cailiao Yanjiu Xuebao/Chinese Journal of Materials Research | Year: 2014

The segregation of solute atoms in hot rolled LT24 aluminum alloy was investigated by atom probe tomography. The results show that a precipitate with composition of Al0.5Mg(Si0.7Cu0.3) can be observed in the grains. No solute segregation can be observed at the interface between precipitates and the matrix. However solute atoms, such as Mg, Si and Cu all tend to segregate at grain boundaries, but the segregation tendency of Cu is much stronger than that of Mg and Si. The concentration of Cu at grain boundaries is 45 times of that at the matrix. Based on the experimental results, the feature of solute segregation and its effect on the performance of the alloy are discussed. © Copyright.

Zhao Q.,Shanghai University | Xia S.,Shanghai University | Zhou B.,Shanghai University | Bai Q.,Shanghai University | And 3 more authors.
Jinshu Xuebao/Acta Metallurgica Sinica | Year: 2015

Alloy 825 is widely used for chemical and petrochemical applications due to its good combination of mechanical properties and corrosion resistance. However, intergranular corrosion (IGC) is one of the serious problems for alloy 825 exposed to aggressive environments, which could result in unexpected failures and lead to huge losses. The grain boundary structure, which can partly be described by coincidence site lattice (CSL) model, can influence the grain boundary chemistry and the susceptibility to intergranular corrosion. The field of grain boundary engineering (GBE) has developed a lot over the last two decades since the concept of grain boundary design was proposed. The aim of GBE is to enhance the grain-boundary-related properties of materials by increasing the frequency of low ΣCSL (Σ≤29) grain boundaries (GBs) and tailoring the grain boundary network. It was reported that in some fcc materials with low stacking fault energy, such as Ni-based alloys, lead alloys, austenitic stain- less steels and copper alloys, the frequency of low ΣCSL GBs can be greatly increased by using proper thermomechanical processing (TMP), and as a result the grain boundary related properties were greatly enhanced. In this work, GBE is applied to the manufacture of Ni-based alloy 825 tubes by cold drawing using a draw-bench on a factory production line and the subsequent annealing. The effect of thermomechanical processing on the grain boundary character distribution (GBCD) of alloy 825 was studied by means of the EBSD technique and orientation image microcopy (OIM). The results show that the proportion of low ΣCSL grain boundaries increase to more than 75% by the TMP after 5% cold drawing and subsequent annealing at 1050℃ for 10 min, and simultaneously the large-size highly-twinned grain- cluster microstructure is formed. The size of the grain- cluster and proportion of low ΣCSL grain boundaries decrease with the increase of pre-strain. The proportion of low ΣCSL grain boundaries decreases with the increase of the mean grain size. The annealing temperatures in the range of 1050~1125℃ have no obvious effect on the GBCD of the specimen with 5% cold drawing deformation; while the proportions of low ΣCSL GBs of the sample with 3%, 7% and 10% cold drawing deformation decrease with the increase of annealing temperature. © All right reserved.

Wu Y.,CAS Hefei Institutes of Physical Science | Qin J.-G.,CAS Hefei Institutes of Physical Science | Liu B.,CAS Hefei Institutes of Physical Science | Liu F.,CAS Hefei Institutes of Physical Science | And 13 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2016

The ITER magnet system is made up of four main subsystems: the 18 toroidal field (TF) coils, the central solenoid, the six poloidal field (PF) coils, and the correction coils (CCs). The feeder system, with its main busbar (MB) and CC busbar (CB), represents one of the main magnet components as well. All coils and busbars with different dimensions used cable-in-conduit conductors. China has signed three conductor packages, which are the so-called procurement arrangements, between ITER and the Chinese Domestic Agency (CN DA): a TF conductor package, a PF conductor package, and a CC and feeder conductor package. They include 7.5% of the TF conductors (11); all the PF2 (12), PF3 (16), PF4 (16), and PF5 (16) conductors; all the CC (18) conductors; and the MB (3) and CB (2) conductors for the feeders. Complex technologies have been developed by ASIPP for the serial production of all ITER conductors, in terms of cabling parameter design, welding, and elaboration of cable insertion, compaction, and winding processes. China has finished all qualification phases and is well into the main series production. All conductor samples required for quality control have successfully passed the SULTAN tests with good performance. The status of the production of ITER conductors in China is described in this paper. © 2002-2011 IEEE.

Qin J.-G.,CAS Hefei Institutes of Physical Science | Wu Y.,CAS Hefei Institutes of Physical Science | Liu B.,CAS Hefei Institutes of Physical Science | Liu H.-J.,CAS Hefei Institutes of Physical Science | And 9 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2014

The design of poloidal field (PF) coils and correction coils (CCs) for the International Thermonuclear Experimental Reactor (ITER) relies on the use of 45-kA NbTi cable-in-conduit conductors. All PF5 and CC conductors are produced in China. Research and development programs are needed to acquire knowledge on the behavior of such conductors. Since the conductors are new, full-size copper dummy conductors have been produced in advance for testing the cabling parameters, the definition of the automatic tungsten-inert-gas welding of a seamless jacket section, the elaboration of cable insertion, compaction, etc. Then, two short qualification conductor samples (the PF5 and the CC) are manufactured at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), Hefei, China, with the NbTi advanced strands produced by the Western Superconducting Technologies Company, Ltd. In this paper, the manufacturing procedures for the two PF5 and CC conductor samples are described in detail. © 2014 IEEE.

Li Z.,Zhejiang Jiuli Hi Technology Metals Co. | Su C.,Zhejiang Jiuli Hi Technology Metals Co. | Wang B.,Zhejiang Jiuli Hi Technology Metals Co. | Lu P.,Zhejiang Jiuli Hi Technology Metals Co. | Zhang J.,Zhejiang Jiuli Hi Technology Metals Co.
Energy Materials 2014, Conference Proceedings | Year: 2014

The new frontier of oil and gas exploration will be with deep wells. Deep wells generally have higher temperature and pressure. Wells are categorized as being either sweet or sour. Sweet wells are only mildly corrosive, while sour wells are very corrosive. Thus, material selection is especially critical for deep sour wells which contain high concentration of hydrogen sulfide, carbon dioxide, elemental sulfur and chlorides. As these conditions become more severe, tubular material selection goes from stainless steel used for sweet wells, to duplex stainless steel, to nickel based alloy such as UNS N08028, UNS N06985 and UNS N08825, for sour well service. In this paper, Alloy TDJ-028 (UNS N08028) seamless pipe used for OCTG's has been developed using hot extrusion and cold worked processing. The mechanical tests show that the minimum yield strength grade of TDJ-028 alloy pipe was higher than 110KSI. The hardness, flattening and impact properties of the pipe and coupling stock were very good. Furthermore, the corrosion data is also presented to show the performance of the Alloy TDJ-028 in sour well environment using SCC, SSC tests. The properties of Alloy TDJ-028 pipe met the specification of ISO 13680 and NACE MR0175. So far, Jiuli has the ability to produce massive Alloy TDJ-028 OCTG's for sour oil and gas wells and the production diameter of the pipe can reach 8 inch.

Su C.,Zhejiang Jiuli Hi. Technology Metals Co. | Zhou Z.-J.,Zhejiang Jiuli Hi. Technology Metals Co.
Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing | Year: 2012

HR3C seamless steel tubes were produced by hot-extrusion and cold rolling processes. The process of metal cold-forming and the performance of finished-products indicate that hot-extrusion and cold rolling processes have obvious advantage in manufacturing finished-products of high alloy steel with hard deformation. Metal withstands three-dimensional compressive stress during deformation in the hot-extrusion process, which can improve the comprehensive performance of metal pipes. The improvement of surface quality and dimension precision through cold rolling processing can ensure the higher safety of materials used in special environment.

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