钒微合金化N80级无缝管成分和工艺优化的模拟研究

Simulation Study on Compositions and Process Optimization of V-microalloyed N80-class Seamless Tube

利用Gleeble模拟技术研究了不同N含量和热加工工艺对N80无缝管(33Mn2V成分)的影响。结果显示,在各种工艺条件下,N含量从0.005%增加至0.014%或0.021%,在保持钢的强度提高的同时,钢的韧性也显著增加。进一步研究表明,当降低再加热温度时,钢的强度略微损失,韧性提高;而钢的中间停冷温度从450℃提高至700℃,工艺从在线常化变化为非在线常化,则使钢的强度有较大提高的同时韧性明显降低。无缝管的上述力学性能变化和V在钢中的溶解和析出行为以及相应的显微组织变化有直接关系。N含量的增加则优化了V(CN)的析出行为。

The synthesis effects of different nitrogen （N） contents and thermal processes on the microstructure and mechanical properties of 33Mn2V steel for N80-class seamless tube were investigated using Gleeble simulation technique. The results showed that when the N content in the steel increased from 0. 005% to 0.014% or 0.021%, for in-line normalizing process, the strength of steel increased, and in the same time toughness of steel increased greatly. The further research showed that while the reheating temperature decreased, the strength of steel became lower slightly and the toughness of it improved. When the cooling-interrupted temperature of steel changed from 450 ℃ to 700℃, the process varied from in-line normalizing to non in-line, which made the strength of steel increased significantly and the toughness decreased evidently. This can be attributed to the dissolution and precipitation behavior of V （CN）. The optimization of V （CN） precipitation can be achieved by the enhanced N.