摘要
采用膨胀法对AISI 4340钢在900～1150℃几种不同温度下进行奥氏体化,以得到不同的奥氏体晶粒度（AGS）,然后快速冷却到室温,得到马氏体组织.实验结果表明：奥氏体晶粒度和晶界析出相对马氏体相变动力学，尤其是马氏体转变温度（tms）产生很大影响。总的趋势是AGS越大,tms越高。在不同的奥氏体化温度段,会有不同的C，N化合物析出,对马氏体形核产生影响。在奥氏体化温度低于1000℃时，AGS增大,tms快速增加。其原因主要是由于AIN等晶界析出相对马氏体形核的促进作用。在奥氏体化温度高于1050℃时，tms随AGS增大而升高，这是因为TiC等溶解温度较高的化合物在晶界析出对马氏体形核起到促进作用。
By means of thermal dilatation a AISI 4340 steel was austenitized at some different temperatures in a range from 900 to 1150℃ to obtain different austenite grain sizes （AGS）, then rapidly cooled to room temperature to obtain martensitic structures. The transmission electron microscopy （TEM） including electron diffraction and microanalysis was used to describe the microstructures. It was found that both AGS and AIN exert a great effect on the martensite transformation kinetics. The larger the AGS, the higher the starting temperature of rnartensite transformation （tms）. Within different austenitizing temperature ranges, there are different kinds of compound precipitates found, affecting the nucleation of martensites. At and below 1 000℃, since the particles of AIN play an important role during the martensite transformation, tms increased rapidly. However at and above 1050℃, tms still increases with AGS. This fact may be due to the precipitation of relatively higher dissolution temperature, such as TiC, on the boundary of austenite.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第6期650-653,共4页
Journal of Northeastern University(Natural Science)
基金
国家高技术研究发展计划项目(2001AA332020)
关键词
奥氏体晶粒度
马氏体
相变动力学
低合金钢
austenite grain size
martensite
transformation kinetics
low-alloy steel
