The hot deformation behavior of P550 steels containing different nitrogen contents (0.63 and 0.86 wt% N) is investigated by isothermal compression tests at 900–1200 °C and 0.05–5 s⁻¹. Electron backscattered diffraction (EBSD) is performed to reveal the effects of nitrogen content, deformation temperature, and strain rate on dynamic recrystallization (DRX) behavior of P550 steels. The results indicate that high nitrogen significantly increases the flow stress and apparent activation energy of P550 steels; it also favors the nucleation of DRX by refining the initial grain size. As the deformation temperature is raised, both the fraction and average misorientation angle of DRX grains increase; however, these values first decrease and then increase with increasing the strain rate. The microstructural changes demonstrate that discontinuous DRX (DDRX) plays a dominant role in the nucleation of DRX for the studied steels, whereas continuous DRX (CDRX) is only a coordinated one.

中文翻译：

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P550钢用于非磁性钻Col的热变形行为

通过在900–1200°C和0.05–5 s ^-1下的等温压缩试验研究了不同氮含量（0.63和0.86 wt％N）的P550钢的热变形行为。。进行电子背散射衍射（EBSD），以揭示氮含量，变形温度和应变速率对P550钢的动态再结晶（DRX）行为的影响。结果表明，高氮会显着增加P550钢的流变应力和表观活化能。通过细化初始晶粒尺寸，它也有利于DRX的形核。随着变形温度的升高，DRX晶粒的分数和平均取向差角都增加；但是，这些值首先随着应变率的增加而减小，然后增加。显微组织的变化表明，不连续的DRX（DDRX）在研究钢的DRX成核中起主要作用，而连续的DRX（CDRX）只是配位的。