材料期刊网

RELATIONSHIP BETWEEN FRACTAL DIMENSION AND CYCLIC CREEP PROPERTIES OF ROTOR STEEL 34CrMoA

YI Jianzhang Shenyang Institute of Aeronautical Engineering , Shenyang , ChinaYANG Zhi'an ZHU Shijie WANG Zhongguang Institute of Metal Research , Academia Sinica , Shenyang , China lecturer , Department of Safety Engineering , Shenyang Institute of Aeronautical Engineering , Shenyang 110031 , China

金属学报(英文版)

Vertical section method has been used to measure the fractal dimension of cyclic creep frac- ture surfaces of rotor steel 34CrMoA at 550℃.The relationship between fractal dimension and cyclic creep properties has been analyzed.The fractal dimension is dependent upon the power product of minimum creep rate and rupture time,and satisfies the linear function with rupture strain.

关键词: cyclic creep , null , null , null

DIFFUSION BONDING OF SUPERPLASTIC AI ALLOY LC4

HUANG Yan , MA Longxiang Northeast Universtity of Technology , Shenyang , China lecturer , Department of Metalforming , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

Diffusion bonding of supcrplastic Al alloy LC4,with prior surface treatment of organic solution protecting coating after electroplishing and stainless steel wool brushing,was performed by Gleeble test machine under conditions ranged 490—530 ℃,1.0—3.0 MPa. 30—180 min and vacuum of 1.0×10~(-3) Pa.The joints were examined to have similar strength and microstructure to the base metal Discussion was made on the effect of superplastic treatment on bonding.The micromechanism for diffusion bonding of super- plastic metal was suggested as the migration of original bond interfaces caused by atomic diffusion and grain growth. Experimental results for the alloy as quench-aged state were presented to compare with the superplastic one.

关键词: superplasticity , null , null , null

HYDROGEN ATTACK ON AUSTENITIC STEEL 304 UNDER HIGH TEMPERATURE AND HIGH PRESSURE

LI Xiaogang CHEN Hua YAO Zhiming LI Jin KE Wei Institute of Corresion and Protection of Metals , Academia Sinica , Shenyang , China lecturer , Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

The hydrogen attack of austenitic stainless steel 304 exposed to hydrogen under the pressure of 5 MPa at 733 K for 2×10~4 h in service was detected.The microstructure has been studied by SEM and TEM.Hydrogen was determined with molten samples which had tempered at.573,673,773,873,and 973 K for 6 h.The results showed that hydrogen attack in this steel was due to methane bubbles which resulted in occuring of Cr_(23)C_6.Thermodynamic analysis of hydrogen attack for stainless steel 304 was discussed.

关键词: hydrogen attack , null , null , null

BEHAVIOUR OF BORON SEGREGATION AT GRAIN BOUNDARIES IN BCC Fe-3% Si ALLOY

ZHANG Sanhong HE Xinlai CHU Youyi~* KE Jun University of Science and Technology Beijing , Beijing , China lecturer , Department of Materials Physics , University of Science and Technology Beijing , Beijing 100083 , China

金属学报(英文版)

The behaviour of baron segregation at grain boundaries in Fe-3% Si has been studied by means of particle tracking autoradiography(PTA).The results indicate that the tendency of equilibrium segregation of B at grain boundaries in Fe-3% Si is higher than that in austenitic alloys.No observable nonequilibrium segregation of B at grain boundaries was revealed in Fe-3% Si alloy during cooling and isothermal holding.The binding energy between boron at- oms and grain boundaries is 55.7±1.7 kJ/mol.Based on the complex mechanism of B segre- gation of quenching-induce-nonequilibrium segregation,different behaviours of B segrega- tion in γ-Fe and bcc Fe-3% Si alloy were discussed.

关键词: Boron , null , null , null

PREPARATION OF B-N FILMS BY ION BEAM ASSISTED DEPOSITION

JIANG Hai TAO Kun LI Hengde Tsinghua University , Beijing , China lecturer , Department of Materials Science and Engineering , Tsinghua University , Beijing 100084 , China

金属学报(英文版)

BN films,synthesized by ion beam assisted deposition,were analysed by RBS,AES, IR spectra and TEM.Formatiom of c-BN phase was shown not only by IR spectra at absorption peak of 1100 cm~(-1),but also by electron diffraction pattern.The results of AES demonstrate an effect of N~+ implantation near the film surface.The deposited films consist of three layers,i.e.,ion implantation layer,film layer and mixed intermediatelayer, according to the difference of concentration.The micro-Knoop hardness of the film is 25—35 GPa.

关键词: ion beam assisted deposition , null

IN-SITU OBSERVATION OF THERMAL FATIGUE CRACK GROWTH IN STEEL 3Cr2W8V

LIU Jianhong HE Shiyu YAO Mei Harbin Institute of Technology , Harbin , China lecturer , Depatment of Metallic Materials , Harbin Institute of Technology , Harbin 150006 , China

金属学报(英文版)

The growing process of thermal fatigue cracking,in steel 3Cr2WSV was observed under desk SEM fitted with sell-made minisized device for thermal faligue test.Before the growing of thermal fatigue crack,the main crack tip reveals to blunt firstly,and some holes and uncontinuous microcraeks occur in front of it.The growth is developed by bridging of main crack together with holes and microcracks.

关键词: steel 3Cr2W8V , null , null , null

STATISTICAL EVALUATION OF CRITICAL INCLUSION FACTOR FOR SECONDARY RECRYSTALLIZATON IN 3%Si STEEL Lecturer,Department of Materials Engineering,Southwestern Jiaotong University,Chengdu 610031,China

LI Shuchen Southwestern Jiaotong University , Chengdu , ChinaCHEN Mengzhe KE Jun University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

On the basis of statistical data of MnS in the conventional 3% Si steel sheeets after various annealing processes,the critical inclusion factor has been evaluated to be 20 mm~(-1).The inhi- bition of MnS to grain growth has been exactly described.

关键词: 3%Si steel , null , null

CORRELATION BETWEEN STRESS COMPONENTS AND STRESS CORROSION CRACKS IN BRASS Lecturer,Department of Materials Physics,University of Science and Technology Beijing,Beijing 100083,China

QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.

关键词: stress corrosion cracking , 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

Recent Advances of Laser Coating Technology in China

LIANG Yong LI Ruiguo Institute of Metal Research , Academia Sinica , Shenyang 110015 , ChinaInstitute of Corrosion and Protection of Metals , Aademia Sinica , Shenyang , 110015 , China

材料科学技术（英）

Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.

关键词: laser , null , null , null , null