摘要
利用热膨胀仪对低碳 Mo-Cu-Nb-B 系微合金钢进行了不同温度的等温实验．结合金相(OM)、透射电镜(TEM) 研究了不同等温条件下组织转变特点．该微合金钢中温转变有三类组织：沿晶界形核并向晶内单方向生长的准多边形铁素体,晶界或晶内形核的针状铁素体和成束生长的板条贝氏体铁素体．620℃为发生准多边形铁素体转变的鼻尖；580℃只发生少量仿晶界铁素体转变,铁素体转变受到抑制；在530℃左右等温时,奥氏体将发生针状铁素体转变,这些针状组织彼此交割、独立生长, 分割原奥氏体晶粒,细化了组织．
The during microstructure evolution of a low carbon Mo-Cu-Nb-B steel during isothermal transformation was investigated by measuring the time-temperature-transformation diagram, in which the dilatometer, optical microscope and transmission electron microscope were used. Three kinds of microstructures are mainly observed in the isothermally held steel： the quasi-polygonal ferrite, intergranularly and/or intragranularly nucleated acicular ferrite and lath-like bainitic ferrite sheaves.The nose of the transformation curve of the quasi-polygonal ferrite is at 620℃. The growth of the constructive ferrite was delayed or restricted at 580 ℃, and thus only a small amount of allotriomorphic ferrite formed at the grain boundary. The acicular ferrite was formed during isothermal holding at 530 ℃. The acicular ferrite plates grew up independently across the prior-austenite grain and distributed randomly, which divided the prior-austenite grain into smaller areas.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第1期54-58,共5页
Acta Metallurgica Sinica
基金
国家重点基础研究发展规划项目 G2004CB1902
国家高技术研究发展计划项目2003AA331020
国家自然科学基金项目50571016资助~~
关键词
低碳微合金钢
中温转变组织
准多边形铁素体
针状铁素体
板条贝氏体
vlow carbon microalloying steel, intermediate transformation structure, quasiolygonal ferrite, acicular ferrite, lath-like bainitic
