Abstract: The process flowsheet for high strength steel 82B (/% : 0. 79 ~0. 83C, 0. 15 〜0. 25Si, 0. 72 -0. 80Mn, ≤0.020P, ≤0. 015S, ≤0. 15Cu, 0. 18 ~0. 30Cr) is BOF-LF-165 mm x 165 mm billet casting-hot rolling to Φ 12. 5 mm coil-cold drawing to Φ5. 05 mm products. It is obtained by analysis on cold-drawn fracture of wire rod that the factors including obvious martensite at center of wire rod and network of cementite produced by segregation, large size MgO-CaO-Al₂0₃ - SiO₂ compound inclusions and surface defects lead to cold drawn fracture of wire rod. With the process measures including decreasing the overheating extent of liquid from original 25 ~35 °C to 15 ~25 °C , decreasing the billet casting speed from 1. 80 m/min to 1. 65 m/min, decreasing the amount of secondary cooling water from 0. 80 L/kg to 0. 65 L/kg, increasing the soft argon blowing time from 10 min to 12 min and insuring aging for 3 h at 250 ℃ after rolling, the rating of center porosity ,center segregation and shrinkage cavity of casting billet decreases respectively from 1. 5, 1. 0 and 0. 5 ~ 2. 5 to 0. 5 , 0. 5 and 0 ~ 0. 5, and the total content of inclusions in steel decreases from 0.0035% 〜0.0043% to 0.0017% ~ 0.0021% to basically avoid the occurrence of cold drawn fracture of wire rod.

摘要： 82B高强度钢（/%:0.790.83C,0.150.25Si,0.720.80Mn,≤0.020P,≤0.015S,≤0.15Cu,0.180.30Cr）的工艺流程为BOF-LF-165 mm×165 mm坯连铸-热轧至Φ12.5 mm盘条-冷拔Φ5.05 mm材。线材冷拔断口的分析得出,因偏析产生明显的中心马氏体和网状渗碳体,大颗粒MgO-CaO-Al₂O₃-SiO₂复合夹杂,表面缺陷等因素导致冷拔断裂。通过钢水过热度由原2535℃降至1525℃,铸坯拉速由1.80 m/min降至1.65m/min,二次冷却水量由0.80 L/kg降至0.65 L/kg,软吹时间由10 min增至12 min,保证轧后250℃ 3 h时效等工艺措施,使铸坯中心疏松、中心偏析和缩孔级别分析从1.5,1.0和0.52.5降至0.5,0.5和00.5,夹杂物总量由0.003 5%0.004 3%降至0.001 7%0.002 1%,基本杜绝线材冷拔脆断出现。