材料期刊网

BEHAVIOURS OF AUSTEN1TE UNDER IMPACT ABRASION

WANG Huaming Institute of Metal Research , Academia Sinica , Shenyang , ChinaZHANG Qing Central Iron and Steel Research Institute , Ministry of Metallurgical Industry , Beijing , ChinaSHAO Hesheng Beijing Graduate School , China University of Mining and Technology , Beijing , China Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

The role of austenite in impact-abrasion process was studied on the basis of the impact-abrasion test results of a newly developed austenite-bainitic ferrite dual-phase abrasion-resistant steel with high strength,high toughness and high strain-hardening ability. It is found that the morphology,distribution and mechanical stability,rather than the volume fraction,of austenite govern the impact abrasion behaviour.Only the appropriate amount of fine and evenly dispersed austenite with adequate mechanical stability in high strength matrices,contribute effectively to the irnpact-abrasion resistance of the materials.While large quantity of coarse austenite with poor mechanical stability,especially when it acted as a continuous matrix of the material,is extremely detrimental to impact-abrasion resistance.

关键词: austenite , null , null , null

INVESTIGATION OF BEHAVIOUR OF B IN Ni_3Al ALLOYS BY POSITRON ANNIHILATION TECHNIQUE

DENG Wen XIONG Liangyue LONG Qiwei International Centre for Materials Physics , Institute of Metal Research , Academia Sinica , Shenyang , ChinaWANG Shuhe GUO Jianting Institute of Metal Research , Academia Sinica , Shenyang , China Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

The behuviour of B atoms added to mono-and poly-crystalline Ni_3AI alloys has been investi- gated hy positron annihilation technique(PA T).If the additive of B was less than 1.37 at-%, some of B atoms solid-solutioned interstitially into matrix and distorted the lattice,thus the lifetime (τ) of positron (e~+) Or matrix dilated:the others of them segregated on vacancy-like defects and formed "filling effect",thus the mean lifetime (τ)and S parameters decreased.If B added was increased up to 2.22 at-%,more defects having larger free volume were induced by horide eutectic occurred along grain boundaries and grain interior,thus the τ in vacancy-like defects.τ and S parameters increased remarkably.

关键词: Ni_3Al , null , null , null

INFLUENCE OF GRAIN SHAPE AND CARBIDE ON CREEP CRACK GROWTH IN HK40

ZHU Shijie Institute of Metal Research , Academia Sinica , Shenyang , China ZHAO Jie Fushun Institute of Petrochemistry , Fushun , China WANG Fugang Dalian University of Technology , Dalian , China Institute of Metal Research , Academia Sinica , Shenyang 110015

金属学报(英文版)

The influence of two different grain shapes and carbides in the HK40 alloy,the material for use of furnace tube,on the rate of creep crack growth has been investigated.The resistance to creep crack growth of the material with columnar grains is inferior than that with equiaxial grains when the load line is perpendicular to the columnar grain axis.The influence of secon- dary carbide on the rate of creep crack propagation depends upon the Brain shape.

关键词: grain shape , null , null

INVESTIGATION ON CRYSTALLIZATION KINETICS OF Pd-Cu-Si GLASS

GAO Wenli SUI Zhitong North East University of Technology , Shenyang , China LU Ke LI Shuling WANG Jingtang State Key Laboratory for RSA , Institute of Metal Research , Academia Sinica , Shenyang , China Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

The crystallization kinetics of Pd-Cu-Si glass was studied by means of diferential scanning calorimetry-Ⅱ.According to Kissinger peak shift methd and Arrhenius equation,the apparent activation energy was calculated.The crystallization kinetics follows Johnson- Mehl-Avrami equation with n=3.0 within 0.15

关键词: amorphous ahoy , null , null , null

INTERACTION BETWEEN CORROSION AND WEAR OF STA LESS STEEL IN H_3PO_4+NaCl SOLUTION

ZHANG Tiancheng JIANG Xiaoxia LI Shizhuo SHI Changxu Institute of Metal Research , Academia Sinica , Shenyang , China Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

Plots of corrosion-wear loss vs load and anodic polarization curves during wearing were for a duplex stainless steel in 69% H_3PO_4 solution with or without Cl~- by a pin-on-disc apparatus.Morphologies of tracks and debris as well as variation of Vicker hardness of worn surface were also examined.The Cl~- may impel the embrittlement and tear of worn surface,so as to accelerate the corrosi-wear loss of the steel.

关键词: duplex stainless steel , null , null

EFFECT OF Zr ON DUCTILITY OF CAST Ni_3 Al-BASE ALLOYS

ZHENG Zhi WU Weiwen GUO Jianting ZHU Yaoxiao Institute of Metal Research , Academia Sinica , Shenyang , China Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

Many compressive and tensile tests showed that the room temperature ductility of boron-free Ni_3Al alloy may be markedly improved by a moderate addition of Zr.The ductility of the stoichiometric Ni_3Al and even slightly enriched with Al,may be improved fairly between 400 —600℃,which behaves much better if Zr is added together with B.However,the high tem- perature ductility of Ni_3Al alloys containing Cr may be significantly increased by Zr which segregates slightly along grain boundaries.Thus,the toughening mechanism of Zr alloying seems to be different from that of B addition.

关键词: Ni_3Al , null , null , null , null

Introduction to atmospheric corrosion research in China

Science and Technology of Advanced Materials

In this paper, we introduce the research on atmospheric corrosion in China. We describe the climate characteristics and the classification of atmospheric corrosivity across the whole country. We also describe the rusting evolution under simulated wet/dry cyclic conditions. (C) 2007 NIMS and Elsevier Ltd. All rights reserved.

关键词: atmospheric corrosion;corrosivity;rusting evolution;weathering steels;rust;mechanism;so2;o-3;no2

MICROSTRUCTURE AND PROPERTIES OF SiC_w/6061Al COMPOSITE The Author is now with Institute of Metal Research,Academia Sinica,China

MA Zongyi YAO Zhongkai Harbin Institute of Technology , Harbin , China

金属学报(英文版)

The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure

关键词: composite , null , null , null

EFFECT OF Cu ON MICROSTRUCTURE AND PROPERTIES OF Al-Li ALLOYS

YAO Daping HU Zhuangqi LI Yiyi ZHANG Yun SHI Changxu Institute of Metal Resarch , Shenyang , China Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

The aging precipitation structure and the properties of Al-Li-Cu-Zr alloys with 3 different Cu/Li ratios have been studied.Experimental results show that the aging hardening of the alloys consists of two steps:The first is strengthened by δ′-phase(δ′+T_1 phase in alloy No.3),and the second by δ′+T_1 phase(δ′+T_1+θ′phase in alloy No.3).The plate of T_1-phase can absorb the Li atoms from δ′ particles when the plate bumped into δ′-phase,and therefore, these δ′ phase particles become smaller and gradually disappear.The strength and hardness increase with the increase of Cu/Li ratio and cuases a decrease in plasticity.The crack mode would change from transgranular to intergranular.This is due to the precipitation of the equi- librium phases contained Cu at grain boundaries.

关键词: A1-Li alloy , null , null , null

Recent developments in high temperature intermetallics research in China

Intermetallics

A comprehensive survey was made of various advances of intermetallics research in China. The investigation focussed on the fundamental research and materials development. Charge density distribution and site occupancy of alloying elements, environmental embrittlement and chemical reaction, interface structures and phase transformation at the atomic scale, nanocrystalline intermetallics and its thermal stability, superplastic behavior and anomalous yield strength peak are reviewed. Several Ti-Al and Ni-Al based alloys have been manufactured, and show good mechanical properties. Diverse components have been fabricated successfully. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词: aluminides, miscellaneous;hydrogen embrittlement;mechanical properties;at high temperatures;superplastic behavior;phase interfaces;grain-boundary fracture;in-situ composites;environmental;embrittlement;hydrogen embrittlement;ni3al;compression;alloys;co3ti;boron;feal