DAI Qixun and YANG Ruzeng(Department of Materials Science and Engineering
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Jiangsu University of Science and Technology
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Zhenjiang212013. China)Manuscript received 8 August 1995
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in revised form 9 April 1995
金属学报(英文版)
The effect of carbide solvation on the γ/γ+δ boundary temperature Tδ and the equilibrium relationship between the alloying elements at the γ/γy +δ boundary in austenitic steels at high temperature have been studied, and the variation of the ferrite volume fraction with temperature in α+ γ dual phase steel has been investigated. The relative expressions are derived from many experimental results, which provides a basis for quantitative calculation, composition design, determination of the working processes,and prediction of the mechanical properties and the structure of the austenitic steels.
关键词:
: carbide solubility
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Zhigang CHEN (Ceramic Research Lab.
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Jiangsu University of Science and Technology
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212013
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Zhenjiang
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China)
材料科学技术（英文）
Wear resistance of several zirconia toughened ceramics in comparison with a metal-ceramic CoWC has been studied in drawing wire field test. Result indicates that the harder the ceramic die, the longer the service life. Excellent wear resistance of ceramic die is obtained with a very high hardness (19 GPa). The service life is nearly three times that of Co-WC die. SEM observation on wear surfaces showed that material removal is mainly caused by plastic flow and ploughing process. But when the ceramic is composed of zirconia, alumina and some titanium carbide, micro-chipping and tribochemical reaction take place, and wear rate increases. Wear and friction induced martensite was detected by XRD. The T-M (tetragonal to monoclinic) phase transformation has a contribution to inhibiting microfracture.
关键词:
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
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Beijing
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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
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