金属学报(英文版)
On the basis of the thermodynamic calculation of precipitation and considering the effect of strain on the precipitation behavior and chemical composition (Si and Mn), the kinetics of precipitation from austenite has been investigated for different temperatures and strains. Nucleation theory and the solubility product of niobium, carbon, and nitrogen in austenite have been used to derive equations for the start time of precipitation as a function of temperature and composition. The value of n in Avrami equation was determined using the available experimental data from the published reports, which indicated that n is a constant independent of temperature and the end time of precipitation is a function of n and the start time of precipitation. The values of the start time and end time of precipitation predicted by the new model are compared with the experimental values and a good agreement was obtained between both.
关键词:
strain-induced precipitation
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null
Zhouyu ZENG
金属学报(英文版)
A static recrystallization behavior between the rolling passes of a martensitic heat-resistant stainless steel 403Nb has been studied by OM, TEM and double-hit thermo-mechanical simulator to explore the effects of deformation temperature, strain rate, strain and the prior austenite grain size. The results show that increases of deformation temperature and strain rate and strain can promote the static recrystallization of 403Nb steel. Static recrystallization also proceeds faster when the prior austenite grain size is smaller. Microstructural observation indicates that the volume fraction of static recrystallization increases with prolonged interval of the rolling passes. Strain-induced precipitation can lead to an appearance of a platform in the kinetic curve of static recrystallization. Different from the conventional micro-alloying steel, the strain-induced precipitates in 403Nb steel during hot rolling are carbides containing Nb and Cr.
关键词:
403Nb
XU Wenchong SUN Fuyu ZHAO Peixiang Central Iron and Steel Research Institute
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Ministry of Metallurgical Industry
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Beijing
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China XU Wenchong Senior Engineer
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Central Iron and Steel Research Institute
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Ministry of Metallurgical Industry
,
Beijing
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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
刘明哲
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苑少强
,
刘义
,
梁国俐
钢铁研究学报
采用热模拟及透射电子显微镜结合纳米束能谱技术,研究了Mn-Mo-Nb-B系多元微合金钢奥氏体变形后等温过程中(松弛)的析出行为.实验结果表明:经变形后,在850℃和900℃保温过程中,Mn-Mo-Nb-B多元微合金钢析出颗粒尺寸在各个阶段均小于相同工艺下Nb-Ti钢中析出相的尺寸.统计结果显示,析出颗粒的尺寸均复合正态分布,并且峰位尺寸接近平均尺寸.析出相中Nb/Ti比随着松弛时间而增大.松弛阶段后期,Mo进入(Ti,Nb)(C,N)的晶格当中,其含量随着时间的延长而增加.
关键词:
Mn-Mo-Nb-B微合金钢
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等温松弛
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应变诱导析出
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碳氮化物
