摘要
针对HRB335钢在轧制过程中出现开裂现象,运用金相显微镜、扫描电子显微镜(SEM)、X射线衍射分析(XRD)、氧氮分析仪以及能谱仪等手段,对钢材的组织结构、断口形貌、氧氮含量以及主要成分进行了分析,以便找到HRB335钢热轧开裂的原因。结果表明,HRB335钢材热轧开裂为脆性断裂,开裂主要原因是穿水工艺控制不好,而并非冶炼所致。开裂部位组织为典型魏氏体组织,导致钢材变脆。钢奥氏体化后,过热或保温时间过长,奥氏体晶粒长大,加之轧制过程中穿水冷却速度过快导致形成魏氏体组织。钢材开裂部氧含量远远高于同类钢材,钢材开裂部位夹杂物数量偏高,导致轧制性能降低,易出现轧制开裂。
The microstructure, fracture appearance, oxygen and nitrogen content and main alloying element content of HRB335 steel were analyzed by microscopy, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and O-N measurement system in order to investigate the reason for crack forming during hot rolling. The experimental results show that the crack of HRB335 steel is a brittle fracture and the main reason is because of bad control of water cooling but not smelting. The microstructure of the crack part of the steel is Widmanstaten structure which makes it more brittle due to bigger austenite grain size of HRB335 steel and rapid water cooling. The oxygen content in the steel is larger than that of similar steel which may converse to nonmetallic inclusions and lead the steel more brittle.
出处
《热加工工艺》
CSCD
北大核心
2011年第6期193-195,共3页
Hot Working Technology
基金
重庆市科委公关项目资助(CSTC2009AB74008)
