摘要
采用35CrMo、T8钢,奥氏体化后以等温淬火等方式在TTT图的孕育期附近令珠光体形核-长大。应用QUANTA-400型环境扫描电镜、JEM-2100透射电镜观察珠光体形核的情况。观察发现,片状珠光体在奥氏体晶界、界棱等处形核,晶核由共析铁素体＋渗碳体两相组成,共析共生。理论计算表明,在700-650℃,临界晶核尺寸r^＊=150-70 nm;临界形核功ΔG^＊=155~292 J/mol。
35CrMo and T8 steels were austenized and then isothermally quenched at the temperature corresponding to the incubation period of their TTT diagrams.The nucleation of pearlite was observed by QUANTA-400 environmental scanning electron microscope and JEM-2100 transmission electron microscope.The results show that lamellar pearlite nucleates at the crystal grain boundary or crystal edge of austenite.The pearlite crystal nucleus consists of two phases,eutectoid ferrite and eutectoid cementite,which can coexist.The theoretic calculation shows that,at the temperature range of 700-650 ℃,the dimension of the critical nucleus is about 150-70 nm and the critical nucleation energy is about 155-292 J·mol^-1.
出处
《金属热处理》
CAS
CSCD
北大核心
2011年第2期14-17,共4页
Heat Treatment of Metals
关键词
奥氏体
珠光体
界面
晶核
共析分解
austenite
pearlite
interface
crystal nucleus
eutectoid decomposition
