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High Temperature Wear Characteristics of a New Hot Work Die Steel CH95

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Journal of Wuhan University of Technology(Materials science) 2006年第3期21卷 7-11页

作者：程先华 school of Mechanical engineering Shanghai Jiao Tong University Shanghai 200030China

High temperature wear characteristics of a new hot work die steel CH95 doped with a small amount of rare earth （ Re ） and boron （ B ） have been investigated and compared with those of conventional die steel H11 at a series of temperatures and loads. Worn surfaces of CH95 steel and H11 steel were analyzed with a scanning electron microscope. It is found that high temperature mechanical properties of CH95 steel are much better than those of H11 steel. The oxide layer formed on the worn surface plays an important role in wear resistance at high temperature. When the load is less than 63.N, the surface oxide layer keeps integrated and the effect of load on high temperature wear is small. When the load is higher than 63.N, the supporting ability of matrix to the oxide layer decreases with the increase of load, which results in an increase of wear rate. Compared with H11 steel, the wear resistance of CH95 steel is much better and the worn surface of CH95 steel is smoother. It is easier for CH95 steel to form a compact and integrated surface oxide layer at high temperature than for Hll steel, which protects the worn surface and reduces wear.

关键词： CH95 steel high temperature wear load worn surface oxide layer

Microstructure and Mechanical Property of Ni Metal Treated by Surface Mechanical Attrition

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材料热处理学报 2004年第5期25卷 161-164页

作者： T.Y. Hsu school of Materials science and {2. Shanghai Jiao Tong University Shanghai 200030China

A nanostructured surface layer can be formed in Ni metal treated by surface mechanical attrition (SMA). The microstructure was investigated by using optical microscope, X-ray diffractometer and transmission electron microscope, respectively. Mechanical property measurements indicate that the yield strength of the surface layer raises significantly while the tensile strength somewhat changes and the elongation percentage reduces severely compared with that of the inside layer. Meanwhile, yield-drop-like phenomenon occurs in the surface layer after SMA treatment. In order to compare the mechanical behavior of nanostructured materials with two phases, Fe-3.Ni nanostructured alloy was also investigated.

关键词：显微结构表面层机械性能表面损耗镍合金

PHASE TRANSFORMATION BEHAVIOR IN THE SPUTTER DEPOSITED Ti-Pd-Ni THIN FILMS

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 319-322页

作者： Q. C. Tian and J.S. Wu Key Laboratory of the Ministry of Education for High Temperature Materials and Tests, school of Materials science and {2., {3. jiao tong University, shanghai 2.0030, china Sch. of Materials Sci. and Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

Ti-Pd-Ni thin films were prepared by sputter deposition at room temperature. The as-deposited thin films were crystallized at 750°C followed by various cooling conditions, and the structural change emerging in the films was characterized by means of both X-ray diffraction (XRD) and differential scanning calorimetry (DSC). It was found that the phase transformation temperatures of Ti50.6Pd3.Ni19.4 ingot we much higher than those of its thin film. The B19' and B19 phases coexisted, together with the Ti2.i type and Ti2.d type of precipitates at the room temperature. Both the B19-B2.one-stage and the B19'-B19-B2.two-stage phase transformations took place when the films experienced thermal change across the region of phase transformation temperatures.

关键词： Nickel Palladium Sputter deposition Thin films Titanium

Asymmetric encryption and signature method with DNA technology

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science china(Information sciences) 2010年第3期53卷 506-514页

作者： LAI XueJia1, LU MingXin2. QIN Lei3. HAN JunSong4 & FANG XiWen11Department of Computer science & {2., shanghai {3. tong University, shanghai 2.0030, china 2.8} of National Information Security, Nanjing University, Nanjing 2.0093. china 3.IOCOMPLEX, 4915 Bathurst St. Unit# 2.9-3.6, ON M2. 1X9, Canada 4National {2. Center for BioChip at shanghai, shanghai 2.12.3. china Department of Computer science & engineering Shanghai Jiao Tong University Shanghai China school of National Information Security Nanjing University Nanjing China BIOCOMPLEX Toronto Canada National engineering Center for BioChip at shanghai Shanghai China

This paper proposes DNA-PKC, an asymmetric encryption and signature cryptosystem by combining the technologies of genetic engineering and cryptology. It is an exploratory research of biological cryptology. Similar to conventional public-key cryptology, DNA-PKC uses two pairs of keys for encryption and signature, respectively. Using the public encryption key, everyone can send encrypted message to a specified user, only the owner of the private decryption key can decrypt the ciphertext and recover the message; in the signature scheme, the owner of the private signing key can generate a signature that can be verified by other users with the public verification key, but no else can forge the signature. DNA-PKC differs from the conventional cryptology in that the keys and the ciphertexts are all biological molecules. The security of DNA-PKC relies on diffcult biological problems instead of computational problems; thus DNA-PKC is immune from known attacks, especially the quantum computing based attacks.

关键词： cryptology asymmetric encryption digital signature biological cryptology DNA

Microstructure characterization of high-energy product Nd-Fe-B thin film

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Progress in Natural science:Materials International 2010年第1期20卷 76-80页

作者： Fang XU~1,Fang YANG~2.Xian-ping DONG~1,Lan-ting ZHANG~1,Wei LIU~2.Zhi-dong ZHANG~2.1.school of Materials science and {2.,{3. jiao tong University,{3. 2.02.0,china 2.Shenyang National Laboratory for Materials science,Institute of Metal Research and International Centre for Materials Physics,Chinese Academy of sciences,Shenyang 110016,china school of Materials science and {2. Shanghai Jiao Tong University Shanghai 200240 China Shenyang National Laboratory for Materials science Institute of Metal Research and International Centre for Materials Physics Chinese Academy of Sciences Shenyang 110016 China

A Si/Mo（50 nm）/Nd-Fe-B（400 nm）/Mo（50 nm）film with relatively high-energy product（BH）max=2.7 kJ/m3.was prepared on a Si substrate heated at 650℃.The microstructure of the film was investigated by X-ray diffractometry（XRD）and high-resolution transmission electron microscopy（HRTEM）.The Nd-Fe-B thin film shows a notable out-of-plane c-axis *** （110）orientated Mo grains is proved to promote the growth of c-axis oriented texture of the Nd2.e14B grains,which is favorable to achieve a high ***-scale spherical Nd-O phases composed of randomly orientated polycrystalline grains and a sharp grain boundary without grain boundary phase between two Nd2.e14B grains are *** coercivity highly depends on a certain amount of Nd-O phase and interface morphology.

关键词： Nd-Fe-B thin films microstructure Nd-O phase magnetic properties

Effect of Post Weld Heat Treatment on Toughness of Base Metal of Nuclear Reactor Pressure Vessel Steel A53.B

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Journal of Iron and Steel Research International 2011年第S1期18卷 412-416页

作者： LI Yun-liang 1,ZHANG Han-qian 1,2.FU Li-ming 1,CHEN Jiang-biao 1,LI Jin-fu 1 (1.school of Materials science and {2.,{3. jiao tong University,{3. 2.02.0,china 2.Research Institute,Baoshan Iron and Steel Co Ltd,{3. 2.1900,china) shanghai jiao {2. Univ Sch Mat Sci & Engn Shanghai 200240 Peoples R China Baoshan Iron & Steel Co Ltd Res Inst Shanghai 201900 Peoples R China

The effect of post weld heat treatment (PWHT) on the toughness of nuclear reactor pressure vessel steel was *** toughness (K JC) and Charpy impact toughness (KVC) were obtained at different temperatures for quenched-tempered (QT) and PWHT A53.B steel plates,*** results show that PWHT increases the ductile-brittle transition temperature,and decreases the K JC and *** using SEM and Electron probe micro-analyzer (EPMA),it is found that the size of the precipitation phases increased and molybdenum precipitated during PWHT *** relationship between the size of the precipitation phases and the fracture toughness are analyzed and the influence of microstructure is also briefly discussed.

关键词： nuclear power plant pressure vessel fracture toughness precipitation phases

ANALYTIC SOLUTION FOR WAVE DIFFRACTION OF A SUBMERGED HOLLOW SPHERE WITH AN OPENING HOLE

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Journal of Hydrodynamics 2010年第3期22卷 295-304页

作者： DONG Man-sheng MIAO Guo-ping ZHU Ren-chuan, FAN Ju State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China school of Civil engineering Hefei University of Technology Hefei 230009 China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China

An investigation is carried out on the interaction of surface waves with a submerged sphere having an opening hole in finite-depth water in this article. Based on the linear wave theory, the method of multipole expansions is used to obtain the fluid velocity potential in the form of double series of the associated Legendre functions with the unknown coefficients of an infinite set. In terms of the body surface boundary condition and the matching condition between the inner and outer flows at the hole, the complex matrix equations for the coefficients of the series are established. The infinite sets of matrix equations are solved by truncating the series at a finite number. The hydrodynamic pressure on the structure surface and the exciting forces acting on the structure are graphically presented. The dynamic pressure on the wave front surface of the sphere varies slightly with angle of opening hole increasing, while that on the wave back surface does obviously. When the angles of opening hole are increasing, the absolute values of the complex exciting forces tend to fall as a whole.

关键词： diffraction surface waves submerged sphere multipole potential

Modeling Study of the Particle Pinning Effect on the Grain Boundary Movement

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Journal of Iron and Steel Research International 2011年第S1期18卷 342-345页

作者： WANG Xue-lun 1,FU Li-ming 2.WANG Wei 3.JIA Zhi-xin 1 (1.Rizhaosteel Technology Center,Rizhao Iron and Steel Co Ltd.Rizhao 2.6806,china 2.{2. of Materials science and {3.,shanghai jiaotong University,shanghai 2.02.0 china 3.Department of Structural Steels,Baosteel Research Institute,shanghai 2.1900,china) Rizhao Iron & Steel Co Ltd Rizhaosteel Technol Ctr Rizhao 276806 Peoples R China shanghai jiao {2. Univ Sch Mat Sci & Engn Shanghai 200240 Peoples R China Baosteel Res Inst Dept Struct Steels Shanghai 201900 Peoples R China

In this work,based on the classical grain boundary (GB) formula and the principle of work-energy conversion,a new physically-based model has been developed to predict the particle pinning force concerning the interaction between second phase particles (SPPs) and the moving *** effect of particles pinning on the GB movement is *** modeling results can be applied to quantitatively determine the critical numbers of SPPs required for complete pining the grain growth,such as the critical SPPs number of the unit GB area,the critical number for single grain stagnation,the critical volume fraction of particles at a given particle *** predictions are in good agreement with the experimental results by Gladman.

关键词： the second-phase particle pinning force physical-based model

Effect of Solute Drag and Precipitate Pinning on Austenite Grain Growth in Ti-Nb Microalloyed Steels

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Journal of Iron and Steel Research International 2011年第S1期18卷 383-387页

作者： FU Li-ming 1,WANG Huan-rong 2.WANG Wei 2.SHAN Ai-dang 1 (1.school of Materials science and {2.,{3. jiaotong University,{3. 2.02.0,china 2.Department of Structural Steels,Baosteel Research Institute,{3. 2.1900,china) shanghai jiao {2. Univ Sch Mat Sci & Engn Shanghai 200240 Peoples R China Baosteel Res Inst Dept Struct Steels Shanghai 201900 Peoples R China

A metallurgical model concerning the co-effect of the Nb solute drag and the complex carbonitride precipitates pinning is proposed to predict the recrystallization austenite grain growth of low carbon Nb-containing microalloyed *** analysis,both predicted and experimental,reveals the precipitate pinning plays a dominate role in suppressing the austenite grain growth with less Nb solute drag effect in high temperature region whereas the Nb solute drag predominates in relatively low temperature region.A factor p is suggested to assess the effectiveness of drag and *** pinning and the drag are more effective in restraining grain growth as p>0 and p<0,respectively.A low carbon Nb microalloyed steel and a kind of Ti-modified low carbon Nb steel by Ti substituting for part of Nb are employed to validate the modeling *** theoretical calculations show a good agreement with experimental results.

关键词： grain growth precipitates pinning solute drag Ti-Nb microalloyed steels