定径和冷却工艺参数对40Mn2V钢N80-1套管组织和力学性能的影响

Influence of Sizing and Cooling Process on Structure and Mechanical Properties of N80-1 Seamless Casing Tube of Steel 40Mn2V

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℃。

Abstract The influence of sizing deformation temperature （820 -920 ℃ ）, 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 ON） for NS0-1 seamless casing tube （ cD139.70 - 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 oc curs 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 x 870 ℃, and as cooling rate 0. 6x 1.1 ℃/s, the sizing temperature is 695-820 ℃.