Abstract: The influence of sizing deformation temperature (820 ~ 920 °C ) , deformation extent (0. 18 ~ 0. 24) and cooling rate (0. 2 ~2. 1 ℃/s) on structure, tensile strength and impact energy of steel 40Mn2V (/% : 0. 41C, 0. 22Si, 1.65Mn, 0.014P, 0. 005S, 0. 15V, 0.021Ti, 0.008 0N) for N80-1 seamless casing tube (Φ139. 70 ~ 339. 72 mm x 6. 20 ~22. 22 mm) is systematically analyzed by hot simulation test, and a math model is established. Results show that at defined sizing deformation temperature, as cooling rate of steel is higher than a critical value, the bainite transformation occurs in structure led to poor impact toughness of steel; steel 40Mn2V is available for the tube size with cooling rate less than 1. 1 ℃/s, the suitable process parameters are that as cooling rate less than 0. 6 ℃/s, the sizing temperature is 695 ~870℃, and as cooling rate 0. 6 ~ 1. 1 °C/s, the sizing temperature is 695 ~ 820 ℃.

摘要： 通过热模拟试验,系统分析了定径温度(820~920℃)、应变量(0.18~0.24)和冷却速率(0.2~2.1℃/s)对N80-1无缝套管(Φ139.70~339.72 mm×6.20~22.22 mm)用钢40Mn2V(/%:0.41C、0.22Si、1.65Mn、0.014P、0.005S、0.15V、0.021 Ti、0.008 0N)组织、拉伸强度和冲击功的影响,并建立了数学模型。结果表明,在给定的定径变形温度下,当冷却速率超过某一临界值时,则发生贝氏体转变对低冲击韧性极为不利。40Mn2V钢适合于钢管冷却速率不超过1.1℃/s的钢管规格,当冷却速率低于0.6℃/s时,合适的定径温度为695~870℃,当冷却速率在0.6~1.1℃/s时,定径温度为695~820℃。