非调质36Mn2V石油套管钢连铸坯的高温延塑性

High Temperature Ductility of Casting Bloom of Non-Quenched and Tempered Steel 36Mn2V for Casing Pipe

采用Gleeble-1500热模拟试验机,研究了石油套管用V微合金化非调质钢36Mn2V(%:0.36C、1.54Mn、0.12V、0.008～0.010N)260 mm×300 mm连铸方坯的650～1350℃的延塑性。结果表明,36Mn2V钢的零强度温度(ZST)为1440℃,零塑性温度(ZDT)为1400℃;36Mn2V钢在熔点(Ts)到650℃温度区间内存在两个脆性温度区,第Ⅰ脆性温度区为熔点～1350℃,第Ⅲ脆性温度区为925～650℃,因此,该钢的矫直温度应控制在925℃以上;由1350℃至试验温度(650～1050℃)的冷却速度(3～8℃/s)对36Mn2V钢高温延塑性没有影响。

The ductility of 260 mm × 300 mm casting bloom of V microalloying non-quenched and tempered steel 36Mn2V （% ： 0. 36C, 1.54Mn, 0. 12V, 0. 008-0. 010N） for casing pipe at 650 - 1 350℃ has been studied by using Gleeble-1500 thermal simulator. Results show that the zero strength temperature （ZST） and zero ductility temperature （ZDT） of steel 36Mn2V are respectively 1 440 ℃ and 1 400 ℃ ; there are two zones for steel 36Mn2V at melting point Ts - 650 ℃, i.e. brittle zone Ⅰ , Ts - 1 350 ℃ and the brittle zone Ⅲ, 925- 625 ℃, therefore the straightening temperature for bloom during casting should be more than 925 ℃; the cooling rate （3 -8 %/s）from 1 350 ℃ to test temperature 650 - 1 050 ℃ has no-influence on hot ductility of the steel.