高碳低合金钢NC6宽扁坯断裂分析及工艺改进  

Fracture Analysis of High Carbon and Low Alloy Steel NC6 and Process Improvement

作　　者：于红 宫春林 王金国 Yu Hong;Gong Chunlin;Wang Jinguo(Technology Center of Dongbei Special Steel Group Co.,Ltd.,Dalian,Liaoning 116105,CHN)

机构地区：[1]东北特殊钢集团股份有限公司技术中心,辽宁大连116105

出　　处：《模具制造》2022年第6期82-86,共5页Die & Mould Manufacture

摘　　要：NC6的生产流程为电炉→LF→VD→模铸8t扁锭→1,050轧机轧制150×815mm扁坯→二平二立可逆式宽扁轧机轧制8~60×810mm宽扁钢。150×815mm轧坯在缓冷退火后发生整炉断裂。经分析得出,加热温度偏高使得晶粒粗大、梯度偏大引起的热应力和组织应力、终轧温度过高及轧后冷却不当使得二次碳化物呈网状析出是坯料断裂的主要原因。通过减少钢锭偏析程度、优化加热温度和升温速度、控轧控冷,有效遏制了坯料断裂缺陷的发生。The production process of NC6 Steel is EAF→LF→VD→Ingot casts 8.0 mt flat ingot→1,050 rolling line rolls 150×815mm flat billet→two flat two stand reversible wide flat rolling line rolls 8~60×810mm wide flat steel bar. The 150×815mm rolled billet breaks after slow cooling and annealing. According to the analysis, the main reasons for the fracture of blanks are that the coarse grain caused by high heating temperature, thermal stress and structural stress generated by high temperature gradient of heating. Besides, the finishing temperature is too high and the cooling after rolling is improper, so that proeutectoid carbides are presented as the condition of cellular precipitation. The fracture of billet can be avoided effectively by reducing the degree of ingot segregation, controlling the heating temperature and heating rate, rolling and cooling.

关 键 词：NC6 加热 断裂 偏析 碳化物 网状碳化物 

分 类 号：TG162[金属学及工艺—热处理] TG142[金属学及工艺—金属学]