CAJ | 학술논문

采用光学显微镜、带能谱的扫描电子显微镜等分析技术观察了不同冷速下La脱氧钢的显微组织，并绘制了静态连续冷却转变图.实验结果发现，在4~10℃·s-1的冷速范围内，钢中会有大量晶内铁素体形成，其中在8℃·s-1冷却时可以获得大量细小且弥散分布的晶内针状铁素体. La脱氧钢中含La夹杂物与α-Fe相有较低错配度，其中La2 O2 S夹杂物与α-Fe相的晶格错配度最小为0.2%，钢中含La夹杂物均可诱导晶内针状铁素体形核并可促进感生形核，进而细化组织.
채용광학현미경、대능보적소묘전자현미경등분석기술관찰료불동랭속하La탈양강적현미조직，병회제료정태련속냉각전변도.실험결과발현，재4~10℃·s-1적랭속범위내，강중회유대량정내철소체형성，기중재8℃·s-1냉각시가이획득대량세소차미산분포적정내침상철소체. La탈양강중함La협잡물여α-Fe상유교저착배도，기중La2 O2 S협잡물여α-Fe상적정격착배도최소위0.2%，강중함La협잡물균가유도정내침상철소체형핵병가촉진감생형핵，진이세화조직.
The microstructures of La deoxidized steels obtained at different cooling rates were investigated by optical microscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer. The continuous cooling transformation diagram of the tested steel was also drawn in this paper. It is found that in the cooling rate range of 4 to 10℃·s-1 , intragranular ferrite can form in the steel. While at the cooling rate of 8℃·s-1 , the microstructure mainly consists of fine and dispersed intragranular acicular ferrite ( IAF) . The lattice disregistry between lanthanum-containing inclusions andα-Fe is small;especially, this value of La2 O2 S is 0. 2%. These kinds of inclusions can induce IAF nucleation and sympathetic nucleation, and also make grains refined.