摘要
热轧板带加热过程中高温氧化将直接影响氧化铁皮的结构、元素分布以及粘附性,进而间接影响后续除鳞效果以及粗轧和精轧后得到的成品钢板表面质量。本文利用Gleeble热模拟试验机模拟Q345B连铸坯粗轧前在1150和1250℃加热阶段的氧化情况,并结合拉伸试验研究了两个温度下氧化铁皮的表面形貌、次生氧化铁皮的裂纹以及氧化铁皮与基体界面处截面形貌和各合金的元素分布。研究表明:高温短时氧化生成的一次氧化铁皮粘附性小,仅微小变形即可完全剥离脱落;次生氧化铁皮粘附性大,但强度低,塑性差,易产生裂纹。此外,次生氧化铁皮与基体界面处反应生成的Fe2SiO4会改变氧化铁皮FeO内层的相间分布,对氧化皮起到钉扎作用,导致氧化皮的粘附性强,这增大了后续除鳞的难度。为改善钢板的表面质量,生产实践中建议在粗轧除鳞前控制钢板氧化铁皮界面温度高于Fe2SiO4凝固温度,以降低氧化铁皮与钢板基体附着力。
High-temperature oxidation of hot-rolled plate in the heating process directly affects the structure,element distribution and adhesion of the oxide scale,which in turn indirectly affects the subsequent descaling effect and the surface quality of finished steel plate after rough and finish rolling.Gleeble thermal simulation testing machine was used to simulate the oxidation of Q345B continuous casting at 1150℃and 1250℃.Then the surface morphology of oxide scale,cracks of secondary oxide scale,cross-sectional morphology and distribution of alloying elements at the interface between oxide scale and matrix at two temperatures were studied.The results show that the primary oxide scale formed at high temperature and short-term oxidation has little adhesion,which can be completely peeled off and shed with only small deformation.The secondary oxide scale has strong adhesion,but low strength,poor plasticity,and easy to crack.In addition,Fe2SiO4 generated by the reaction between the secondary oxide scale and the matrix interface will change the interphase distribution of the inner layer of the FeO oxide scale,which plays a pinning effect on the oxide scale,resulting in strong adhesion,which increases the difficulty of subsequent descaling.In order to improve the surface quality of steel,it is recommended to control the interface temperature of the oxide scale on the steel plate higher than the solidification temperature of Fe2SiO4 before rough rolling and descaling to reduce the adhesion between the oxide scale and the steel matrix in the production practice.
作者
郭庆
王俊
程磊
余伟
GUO Qing;WANG Jun;CHENG Lei;YU Wei(Institute of Engineering Technology,University of Science and Technology Beijing,Beijing 100083,China;National Engineering Research Center for Advanced Equipment for Plate and Strip Production,Beijing 100083,China)
出处
《材料科学与工艺》
CAS
CSCD
北大核心
2023年第4期34-40,共7页
Materials Science and Technology
