摘要
通过新设计的具有快速加热和淬火功能的相变内耗仪,对 Cu-Zn-Al 合金和18Cr_2Ni_4WA钢的贝氏体相变内耗进行了测量。实验表明,当在贝氏体相变区等温时,在贝氏体相变孕育阶段,存在一个随时间变化的内耗峰值,此峰值随孕育期减少而增加。Cu-Zn-Al 合金的频率和18Cr_2 Ni_4WA 钢的频率在孕育期内都较低,但前者比后者更显著。这些现象,显示了贝氏体相变在孕育期内存在某种结构变化,其实质是由点阵不稳定性或局部软化所导致的形核。
By the use of new-designed transformation internal frictioninstrument,in which specimen can quickly heated and quenched by argonspraying,changes in internal friction and frequency during the course of baini-cti transformations in 18Cr2Ni4WA steel and Cu-25.83Zn-3.96Al(wt-%)al-loy were measured.Experimental results show that there exists an internalpeak associated with the lowering of frequency within the incubation period.The internal friction Q^(-1) increases and the time required for getting Q_(?)dec-reases with the decrease of incubation period.It may be argued that the str-ucture change within the incubation period is a nucleation process accompa-nay the local softening and/or lattice istability of the parent phase.
关键词
贝氏体
预相变
铜
锌
铝
transformation
pretransforma tion
bainite
internal riction
local soften model
