Abstract: The production flowsheet for casting bloom of test low carbon cold heading steel (/% :. 0.14 ~0.20C, ≤0.20Si, 0.3 ~ 1.0Mn, ≤0.030P, ≤0.035S, 0 ~0.001 9B) is 80 t BOF-LF-280 mm x 325 mm bloom casting process. The effect of 0. 14% 〜0. 20% C and 0 ~ 0. 001 9% B on mechanical properties of the cold heading steel at 600 ~ 1 200 °C has been studied by using Gleeble-3500 thermal simulation machine. Results show that the III brittle zone of the steel is 700 ~ 900 ℃, as the C content in steel is higher the temperature of minimum plasticity of steel is lower； the boron promotes to occur of two valleys in 700 ~ 950℃ brittle zone, but as the B content in steel is up to 0. 001 9% , the elevated temperature plasticity of steel is improved. At 850 ~ 1 200 ℃ each test steel has better plasticity to be suit for larger deformation, therefore straightening and hot-working temperature should be controlled at more than 850 °C.

摘要： 试验的低碳冷镦钢(/%:0.14~0.20C,≤0.20Si,0.3~1.0Mn,≤0.030P,≤0.035S,0~0.001 9B)连铸坯的生产流程为80 t BOF-LF-280 mm×325 mm坯连铸工艺。通过Gleeble-3500热模拟机研究了0.14%~0.20%C和0~0.001 9%B对该冷镦钢600~1 200℃力学性能的影响。结果表明,该钢第Ⅲ脆性区为700~900℃,当钢中C含量较高时,最低塑性的温度较低,硼促使该钢700~950℃脆性区出现两个低谷,但当硼含量增加到0.001 9%时,该钢的高温塑性得到改善。在850~1 200℃,各试验钢的塑性良好,适合较大程度的变形,矫直温度和热加工温度宜控制在850℃以上。

关键词: 碳, 硼, 低碳冷镦钢, 连铸坯, 高温力学性能