高碳盘条网状渗碳体控制工艺研究

Study on Control Technology of Network Cementite of High Carbon Wire Rod

为了降低盘条深加工过程中的异常断裂率,利用光学显微镜和扫描电镜对异常断裂进行了检测,确定了造成异常断裂的组织原因(网状渗碳体),并利用热模拟研究了变形温度及冷却速度对网状渗碳体的析出影响。结果表明:盘条心部的网状渗碳体降低了材料塑韧性,是造成深加工异常断裂的主要原因。在盘条轧制过程中,应避免在700~790℃(特别是700~730℃)范围内进行轧制,且盘条的轧后冷速尽量控制在10℃/s以上,以抑制网状渗碳体的析出。

In order to reduce the abnormal fracture rate during the deep processing of wire rod,the abnormal fracture was detected by optical microscope and scanning electron microscope,and the cause of abnormal fracture(reticulated cementite)was determined.The influences of deformation temperature and cooling rate on the precipitation of network cementite were studied by means of thermal simulation.The results show that the network cementite in the core of the wire rod can reduce the plastic toughness of the material,and it is the main reason for the abnormal fracture during the deep processing.During the rolling process of wire rod,it is necessary to avoid rolling at 700-790℃(especially 700-730℃),and the cooling speed of wire rod after rolling should be controlled above 10℃/s as far as possible,so as to restrain the precipitation of reticulated cementite.