母相压缩变形对Fe23Ni0.55C合金{259}_(f)马氏体转变的影响

Influence of Parent Phase's Compression Deformation on Martensitic Transformation of Fe23Ni0.55C Alloy

利用扫描电镜(SEM)观察了母相压缩变形对Fe23Ni0.55C合金{259}_(f)马氏体转变的影响.试验结果表明,母相压缩变形使{259}_(f)马氏体转变的Ms点(马氏体开始形成温度)升高,变形量较小时Ms点升高较快,变形量较大时Ms点升高的趋势不如变形量较小时明显;变形量较小时{259}_(f)马氏体没有择优取向,母相压缩变形量为30%时的马氏体和对应的表面浮凸沿滑移线方向分别以细片状和细条状平行排列成“簇”;变形量较小时{259}_(f)马氏体片的边界与未变形相比更平直,30%母相压缩变形得到的马氏体片边缘较破碎,而经50%母相压缩变形后,不但马氏体片的边缘较破碎,而且中脊也开始弯曲或折断,在浮凸表面上表现为小的沟痕.

Influence of parent phase's compression deformation on{259}_(f)martensitic transformation of Fe23Ni0.55C alloy is observed with Scaning Electric Microscope(SEM).It shows that with the increase of compression deformation of parent phase,Ms point(starting temperature of martensitic transformation)of{259}_(f)martensitic transformation is rising.With small compression,Ms point increases obviously,while as compression is large,the increase is obscure.With small compression,{259}_(f)martensite appears to be no orientational,while as compression is reaching 30 percent,{259}_(f)martensite and its surface relief are both parallelly arrayed,formed into'packets'.With small compression,border of{259}_(f)martensite becomes more flat and smooth than that without compression.However,as compression is reaching 30 percent,border of{259}_(f)martensite appears to be ragged,and as compression is reaching 50 percent,not only border is ragged,but also midrib of{259}_(f)martensite is fragmental or banded,resulting in some small grooves on its surface relief.