摘要
采用高温激光共聚焦显微镜原位观察和电子背散射衍射技术研究TiN粒子在低合金高强度钢模拟大线能量焊接热循环过程中晶粒细化效果.研究发现合理的Ti和N含量能形成大量细小弥散分布的纳米级TiN粒子,在焊接热循环过程中有效钉扎热影响区粗晶区奥氏体晶界,抑制晶粒粗化.同时,TiN附着在Al2O3表面析出,在冷却过程中有效促进针状铁素体形核,得到有效晶粒尺寸非常细小的由少量针状铁素体和大量贝氏体构成的复合组织.
The effect of grain refinement by TiN particles in the simulated coarse-grained heat-affected zone of a high-strength low-alloy steel was investigated by means of analytical characterization techniques such as in-situ microscopy and electron back scattered diffraction analysis. Abundant finely dispersed nanoscale TiN particles form in the specimen and effectively retard the grain boundary migration during simulated high heat input welding,which results in refined austenite grains. TiN precipitates on the surface of aluminum oxide,which is the effective nucleation site for acicular ferrite during the cooling process and induces the austenite transform to the fine-grained mixed microstructure of a small proportion of acicular ferrite embedded in predominantly bainite.
出处
《工程科学学报》
EI
CSCD
北大核心
2016年第3期371-378,共8页
Chinese Journal of Engineering
基金
中国博士后科学基金资助项目(2014M550414)
武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室开放基金资助项目(FMRU201306)
关键词
高强度钢
低合金钢
热影响区
晶粒细化
氮化钛
原位观察
high-strength steels
low-alloy steels
heat-affected zone
grain refinement
titanium nitride
in-situ observation
