TANG Guoyi ZHENG Yangzeng Yanshan University
,
Qinhuangdao
,
ChinaCAI Qigong
,
ZHU Jing Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China TANG Guoyi
,
Dept.of Graduates
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing 100081
,
China
金属学报(英文版)
The effects of chemical composition and cooling rate after solidication on the grain coarsening temperature,T_(GC),of the V-Ti-N microalloyed steels have been investigated.It is shown that the T_(GC) may be obviously raised by adding even a little Ti to the base steel so as to pre- cipitate a great deal of fine Ti-bearing particles of about 10 nm.The T_(GC) does not increase with the cooling rate,as it is over a certain critical value.The T_(GC) is insensitive to any varia- tion of N content at simulated cooling condition of 150 mm continuous cast slab.The T_(GC) may be dropped down about 100℃ by adding 0.33 wt-%Mo to the steels.The sensitivi- ty of T_(GC) to cooling condition relates to the Ti and V contents.
关键词:
microalloyed steel
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null
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null
ZHAO Yu HE Zhongzhi WENG Yuqing WU Baorong Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China Doctorate Student
,
Department No.2
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing 100081
,
China
金属学报(英文版)
When Sn segregated at grain boundaries of high induction oriented silicon steel,no remarka- ble interaction between Sn and other elements was observed.At the starting temperature of secondary recrystallization,950℃,a certain Sn still segregates at grain boundaries.Sn seems to act as a supplemental inhibitor through grain boundary segregation.According to theoreti- cal analysis,an addition of Sn may decrease the secondary recrystallization temperature of high induction oriented silicon steel,and it is in agreement with the experimental result.
关键词:
silicon steel
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null
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null
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null
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ZHAO Pu LU Shiying Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China ZHAO Pu Engineer
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
The SCC susceptibility of the plastically pre-deformed 18-5-Nb duplex stainless steel to lo- calized corrosion was evaluated in both 25% NaCl+1% K_2Cr_2O_7 and 42% MgCl_2 boiling so- lutions.The y phase in the steel is metastable at room temperature and the γ-α′ martensitic transformation can be induced by cold plastic deformation.With the increase in cold deformation,the volume fraction of α′ martensite increases.Cold plastic deformation results in a remarkable deterioration of SCC resistance of the steel in chloride-containing solutions, resulting from the decrease in corrosion resistance of γ phase in the duplex.It is indicated that, in NaCl solution,the SCC in 18-5-Nb duplex stainless steel initiates at pits and the selective attack on γ phase plays a significant role in the initiation and propagation of SCC.
关键词:
duplex stainless steel
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null
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XU Wenchong MA Xiang SUN Fuyu ZONG Guisheng Central Iron and Steel Research Institute
,
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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null
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null
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null
XU Wenchong SUN Fuyu ZHAO Peixiang Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China XU Wenchong Senior Engineer
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
The kinetics of the isothermal precipitation of(Nb,V)CN in Nb-V alloys has been investi- gated by using the Formastor-press simulator and the extraction replica method.Under four deformation amounts(0,10,30,50%)and three temperatures(1100,1000,850℃), four types of kinetic curves were found.
关键词:
Nb-V microalloy
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null
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null
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null
XU Wenchong SUN Fuyu Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China XU Wenchong Senior Engineer
,
Dept.No.13
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing 100081
,
China
金属学报(英文版)
The lattice constants and chemical composition of Ti,Nb and V precipitates with different particle sizes have been measured hy means of CBED and EDAX.It was obtained that the concentration ratio Of Nb and V,C_(Nb)/C_V,and the lattice constants in the Nb-V steel de- crease with the decrease of the particle size of the precipitates,but there is no regularity for tattice constant of Ti,N b and V precipitate against their particle size in the Ti-V-Nb steel.
关键词:
microalloyed steel
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null
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null
ZHOU Qianli DU Ting Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China Senior engineer
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
The solid oxide electrolyte galvanic cell represented by Mo/Cr,Cr_2O_3//ZrO_2(MgO)//[O], Ce_2O_2S/Mo+ZrO_2 ceramic-metal,Mo have been used to study the thermodynamic proper- ties of Fe-Nb-Ce solution containing trace carbon at 1600℃.The equilibrium constant for the reaction Ce_2O_2S=2[Ce]+2[O]+[S] and the standard free energy of formation of Ce_2O_2S have been determined in liquid iron at 1600℃ as K=4.395×10~(-15).ΔG_(Ce_2)O_2S=-514.786 kJ·mol~(-1).The interaction coefficients between cerium and niobium are found to he e_(Nd)~(Ce)=-2.306,e_(Nd)~(Ce)=-3.481. The equilibrium products began to contain the compound NbC with the increase of Nh concentration in the condition of trace carbon.The formation of NbC is discussed in this work.The standard free energy of formation of NbC in liquid iron at 1600℃ have been de- termined as ΔG_(NbC)=-87.111 kJ·mol~(-1).
关键词:
Fe-Nb-Ce liquid solution
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null
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null
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null
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WANG Yingshu SUN Fuyu XU Wenchong Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China Senior Engineer
,
Department No.13
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
By means of riM-190 hot-stage microscopy,the in situ observation of α-β transformation in 12Cr2MoWVTiB steel has been carried out.The sequence of the growth of ferritic needles composing bainitic basket has also been determined.According to the crystallographic analy- sis a multislip system transform model concerning the formation of basket has been proposed.
关键词:
α-β transformation
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null
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null
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null
LI Jian SUN Fuyu Central Iron and Steel Research Institute
,
Beijing
,
China Engineer
,
Department No.4
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing 100081
,
China
金属学报(英文版)
The volume fraction of proeutectoid ferrite transformed from deformed austenite fv as a func- tion of isothermal time t has been investigated in 0.037% Nb microalloyed steel.The results show that lnln(1-fv)~(-1) vs Int relation does not follow the Avrami equation strictly and con- sists of two straight lines.By comparing the differences between the results and Cahn's theory, the authors' idea has been expounded.
关键词:
austenite deformation
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null
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null
LUO Yang JI Qigen ZHANG Ning SU Xiujin Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
ChinaSUN Daliang Shandong University
,
Jinan
,
China senior engineer
,
Department of Precious Alloys
,
Central Iron and Steel Research Institute
,
Beijing
,
China
金属学报(英文版)
Based on the observation of temperature variation of both domain structure and magnetic con- trast.the thermal demagnetization and randomness of domain nucleation was discussed.
关键词:
domain structure
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null
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null
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