硅元素对炉生铁皮界面微观结构的影响研究  

Research on the effect of Si element on the interface microstructure of oxide scale forming in the heating furnace

作　　者：王畅[1] 于洋[1] 王林[1] 庞在刚[1] 陈瑾[2] 焦会立[2] WANG Chang YU Yang WANG Lin PANG Zai-gang CHEN Jin JIAO Hui-li(Shougang Research Institute of Technology, Beijing 100043 ,China Shougang Qianan Steel Company, Qianan 064404, China)

机构地区：[1]首钢技术研究院,北京100043 [2]首钢股份公司迁安钢铁公司,河北迁安064404

出　　处：《轧钢》2016年第5期6-10,共5页Steel Rolling

摘　　要：钢铁板带产品生产中发现,随着Si含量的增加,红铁皮缺陷比例增加,热卷表面质量下降。红铁皮产生的原因主要与Fe_2SiO_4的液相温度有关,但目前对富Si相熔融的微观特征研究鲜少报道。本文通过热重模拟实验,研究分析了加热温度、保温时间和钢中Si含量等因素对铁皮界面结构的影响。研究发现:Si质量分数为0.15%时,基体与铁皮界面无典型的富Si颗粒带,Si质量分数大于0.50%时,界面富集层明显;低温模拟试样富Si层为颗粒带,高温下为网状形貌;进一步观察高温模拟试样,界面处存在富Si层锚状侵入形貌,其形成原因为Fe_2SiO_4相高于1 170℃时为液相,其渗透和流动性更强,在钢基体内部裂纹和晶界等缺陷处加速氧化,此结构为高Si钢炉生铁皮难以除去的关键。It had been proved by production practice that the red scale defect presence possibility increased obviously with the increasing of Si element content inducing poor surface quality of hot rolled coil.The presence of red scale defect was mainly related to the Fe_2SiO_4 phase existing between steel base and oxide scale,but the micro morphology of the Si element enriched phase had not been comprehensively analyzed or reported.Several influencing factors,such as heating temperature,heating time and the Si element content,on the interface structure had been researched in this paper through thermo-gravimetric analysis experiment.The results show that Si element enriched phase band existing as particles morphology can′t be found at the interface for the steel grade with Si element of 0.15%.However,for the steel grade with Si element content higher than 0.50%,the formation of Si element enriched phase layer is accelerated obviously.Meanwhile,the Si element enriched phase exists as particles band at the interface under lower temperature and as network morphology penetrating to the steel base like ＂anchor＂ under elevated temperature because of higher permeability and flowability of Fe_2SiO_4 phase which exists as liquid phase when heating temperature is higher than the liquidus temperature of 1 170 ℃.The penetrating of Fe_2SiO_4 phase to the steel base along subsurface crack or grain boundary will accelerate oxidation rate of steel base and play as a mainly reason inducing descale difficulty of red scale forming in the heating furnace.

关 键 词：红铁皮 加热炉 Si元素富集 热轧 

分 类 号：TG335.11[金属学及工艺—金属压力加工]