摘要
利用Gleeble-3500热模拟试验机进行双道次压缩试验,研究了Ti对700 MPa级高强度汽车大梁钢静态软化行为的影响。通过测量不同温度和不同道次间隔时间的"应力-应变"曲线,计算出了相同条件下无Ti钢和含Ti钢的再结晶体积分数。结果表明,Ti的添加不仅可以在高温下阻碍等轴晶粒的长大,而且能够抑制形变奥氏体的静态再结晶行为,降低静态软化率。添加0.04%Ti后,静态再结晶激活能由260 kJ·mol^(-1)提高至321 kJ·mol^(-1)。静态再结晶激活能的提高归因于含Ti钢中形成的(Ti,Nb)(C,N)等析出相在高温度下对晶界迁移的阻碍。
Effect of Ti on static recrystallization softening behavior of automobile beam steel with yield strength of 700 MPa was investigated by means of thermal simulation of isothermal double compression on a Gleeble-3500 thermo-mechanical simulator,and the static recrystallization rate was obtained through the tested stress-strain curves.The recrystallization percentages of Ti-free steel and Ti-bearing steel were calculated by the strain-stress curves.The results show that the addition of Ti has an obvious retardation effect on the static recrystallization as well as the growth of the equiaxed grains.The static recrystallization percentage decreases with the addition of 0.04%Ti.The critical activation energy for recrystallization process increases from 260 kJ·mol^（-1） to 321 kJ·mol^（-1） for the steel by addition of Ti due to the dragging effect of（ Ti,Nb）（ C,N） precipitates on the grain boundary at high temperatures.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2016年第10期138-145,共8页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51174020
51374018)
国家高技术研究发展计划资助项目(2013AA031601)
关键词
汽车大梁钢
静态再结晶
激活能
析出相
automobile beam steel
static recrystallization
activation energy
precipitate
