YU Xuejie WANG Jianlin Shanghai Iron and Steel Research Institute
,
Shanghai
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ChinaZHOU Tianjian Anhui Institute of Technology
,
Hefei
,
China YU Xuejie
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Senior Engineer
,
Shanghai Iron Steel Research Institute
,
1001 Taihe Road
,
Wusong
,
Shanghai
,
China.
金属学报(英文版)
In order to clarify that the IFP and the “Type 2”α phase are also arising from TiC,a metastable β-Ti alloy was selected for investigation in this work.The results showed that af- ter heating the alloy just below the α+β→β transus temperature and quenching,the TiC lay- er existed at the α/β interface.The morphology of TiC is similar to that of the IFP arising from TiH_2 in the α-β two-phase alloys.The IFP TiC also provided an easy crack path or the crack initiation sites.The fracture is also identical to that caused by IFP TiH_2.The arced diffractions(characteristic of “Type 2”α)were found in the selected area diffraction pat- terns of some specimens which had been isothermally aged after solid solution treatment.The particles which bring on the arced diffractions may be TiC on the basis of structure and lat- tice parameter analysis,not the so called “Type 2”α phase.
关键词:
interface phase(IFP)
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XU Wenchong MA Xiang SUN Fuyu ZONG Guisheng Central Iron and Steel Research Institute
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Ministry of Metallurgical Industry
,
Beijing
,
China XU Wenchong
,
Senior Engineer
,
Department No.13
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
The strain-induced isothermal precipitation and the law of coarsening of Nb,V and Ti carbonitrides in Nb-steel.V-steel.Nb-V steel and Ti-V-Nb steel have been investigated systematically by means of STEM,EDAX,a new extraction replica technique and the quanti- tative phase analyses method.
关键词:
microalloyed steels
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REN Jianshi ZHAO Huilin ZHANG Gongshu Institute of Metal Research
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Academia Sinica.Shenyang
,
China ZHANG Gongshu
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Senior Engineer
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
Glow discharge cathodic sputtering of alloys containing second phase precipitates or injected oxide particles has been observed with energy dispersive X-ray spectrometer and scanning electron microprobe.It was shown that the formation of cones during the sputtering in these alloys is due to masking of the matrix by glow sputtering second phase precipitates or oxide particles.At steady state,the density of cottes were found to be a function of the densities pre- cipitates or oxide particles in bulk alloy.In addition to the changes of local sputtering rate,the electrostatic effect may play a role on the formation fo cones.
关键词:
glow discharge
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ZHENG Yunrong RUAN Zhongci Institute of Aeronautical Materials
,
Beijing
,
China ZHENG Yunrong
,
Senior Engineer
,
Laboratory No.4 Institute of Aeronautical Materials
金属学报(英文版)
In consideration of the envelopment of γ dendrites by the Hf-rich melts at the late period of solidification of the cast Ni-base superalloys containing Hf,a heat of brazing filler alloy composed of Ni-18.6Co-4.5Cr-4.7 W-25.6Hf(wt-%)was prepared.This alloy is hypereutectic.γ phase is the leading phase in eutectic γ+Ni_5Hf and γ bars are surrounded by Ni_5Hf phase.At the section perpendicular or parallel to the γ growing direction,the eutectic morphology is cellular or laminar respectively.The content of Ni_5Hf in the alloy is 68.7v.-%. The compositions of primary and eutectic Ni_5Hf are very similar.Ni,Co and Hf are the main elements and solubility of Cr and W in Ni_5Hf is very low.This alloy is an ideal brazing filler suitable to the directional or single crystal superalloy,and the elements are beneficial to superalloys properties.This filler alloy is of low melting point and of good fluidity.After braz- ing at 1240℃,5 min+1190℃,I h in 10~(-3) Pa vacuum,the microstructure of bond is the same as that of Hf-bearing superalloy.No Si and B contamination is involved.
关键词:
Ni-Hf brazing alloy
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