低碳钛、钒微合金钢中的相间析出

Interphase precipitation in low carbon Ti-V microalloyed steels

针对目前较少关注的Ti-V微合金体系,在Formaster—FII膨胀仪上进行奥氏体/铁素体两相区等温,在铁素体相变同时获得Ti、V复合相间析出。采用金相、透射电子显微镜对显微组织、尤其是相间析出形貌、及其与铁素体基体的位向关系进行了观察与分析。研究表明,650℃为静态等温相变的鼻温点,相间析出呈层状分布,具有平面和曲面两种形貌,相间析出碳化物与铁素体基体之间存在Baker-Nutting取向关系。

The present study focuses on the Ti-V microalloying system which draws less attention. By using the Formaster-FII dilatometer,the sample was held at austenite/ferrite dual-phase temperature region and the Ti-V complex interphase precipitates were obtained during the austenite to ferrite transformation. Optical Microscopy （OM） and transmission electron microscopy （TEM） were employed to analyze the microstructure , especially the morphology of the interphase precipitate and its crystallographic orientation relationship with ferrite matrix. Studies show that 650℃is the nose temperature for static isothermal transforma-tion. The interphase precipitates exhibit sheet-like distribution,including flat and curved sheets and adopt Baker-Nutting orientation relationships with the ferrite matrix.