（1. Key Laboratory of Electromagnetic Processing of Materials （Ministry of Education）， Northeastern University， Shenyang 110819， Liaoning， China 2. School of Metallurgy， Northeastern University， Shenyang 110819， Liaoning， China 3.Qiguang Technology Co.， Ltd.， Shenyang 110000， Liaoning， China 4. Weifang Special Steel Group， Weifang 261201， Shandong， China 5. Quality Center of Angang Steel Co.， Ltd.， Anshan 114021， Liaoning， China）
Abstract：During the steel wire drawing production or the tensile test from 82B wire rods， those processes cannot be carried out continuously due to brittle fracture of steel wires. The shape of fractures is pen-tip or cone shaped. In this study， some selected samples with fractures from a steel plant were cut， polished and analyzed by means of macrostructure and metallographic examinations to investigate the reason of fracture. The results show that the direct cause of brittle fracture is the existence of cementite network， cavity and micropore in the center of 82B steel wires， which originate from central segregation， shrinkage cavity and porosity in continuous casting billets. Therefore， those defects in wire rods and final products are derived from continuous casting billets in the early stage. Some countermeasures， such as proper molten steel composition and pouring temperature， heat treatment， conventional electromagnetic stirring and electromagnetic swirling flow in nozzle and so forth， are proposed to improve solidification structure and eliminate the pen-tip shaped fracture defect in the end.
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2018, Vol. 37 
