王正军
,
司乃潮
,
王俊
,
丁冉
,
万浩
,
刘光磊
材料工程
doi:10.11868/j.issn.1001-4381.2015.000077
为弥补Al-10Sr中间合金对A356铝合金变质处理的不足,采用自制的Al-5Ti-1B-1RE中间合金与Al-10Sr中间合金对A356铝合金进行动态复合细化变质处理,研究变质处理后合金的显微组织,并与理论计算结果进行了比较.结果表明:采用J J-1型精密增力电动搅拌器对熔体进行强力搅拌、振动,动态复合细化变质不仅能使共晶硅相由粗大的板片状转变为细密的颗粒状,并在α-Al边界均匀析出,而且使α-Al相明显细化,力学性能显著提高,与约翰逊-梅尔方程理论对组织晶粒尺寸控制研究结果相一致;同时A356铝合金熔体吸气倾向显著减轻,与热力学近似计算方程和斯托克斯定律对除气机制进行定量计算研究结果相一致.
关键词:
动态复合细化变质
,
铝合金
,
约翰逊-梅尔方程
,
热力学近似计算方程
,
斯托克斯定律
Z.G. Li
,
H.B. Chang
,
T. Y. Hsu
,
Z. Y. Xu
,
and X. Y. Ruan (Department of Plasticity of Technology
,
Shanghai Jiao Tong University
,
Shanghai 200030
,
China)(Department of Metallurgical Engineering
,
Shanghai Technical College of Metallurgy
,
Shanghai 200233
,
China)(Department of Materials Science
,
Shanghai Jiao Tong University
,
Shanghai 200030
,
China)
金属学报(英文版)
Supposing carbon contents of ferrite phases in pearlite precipitating from austenite in multicomponent steel at temperature T and in Fe-C ystem at T' are the same the pearlite formation temperature diference, can be calculated from the FeX phase diagrams and the equilibrium temperature Al. Using Tp and Fe-C binary thermodynamic model, the driving forces for phase transformation from austenite to pearlite in multicomponent steels have been successfully calculated. Through the combination of simplified Zener and Hillert's model for pearlite growth with Johnson-Mehl equation, using data from known TTT diagrams, the interfacial energy parameter and activation energy for pearlite formation can be determined and expressed as functions of chemical composition in steels by regression analysis. The calculated starting curves of pearlitic transformation in some commercial steels agree well with the experimental data.
关键词:
pearlite formation temperature difference
,
null
,
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