Creep deformation and rupture behaviour of P91 and boron-added P91BN steels were investigated over the stress range of 100–350 MPa at 823, 873 and 923 K. The time spent in each creep regime was significantly higher in P91BN steel as compared to P91 steel. The reduction in the minimum creep rate in P91BN steel about one to two orders of magnitude was observed than that in the P91 steel. An addition of boron (0.006 wt-%) with controlled nitrogen content (0.011 wt-%) in P91BN led to better creep rupture strength than the P91 steel. Using the Larson–Miller parametric method, creep rupture strength evaluated at 873 K for 10⁵ h life was about 33% enhancement in the case of P91BN steel than P91 steel.

研究了 P91 和添加硼的 P91BN 钢在 823、873 和 923 K 时在 100–350 MPa 的应力范围内的蠕变变形和断裂行为。与 P91 钢相比，P91BN 钢在每个蠕变状态中花费的时间明显更长. 观察到 P91BN 钢的最小蠕变速率比 P91 钢降低了大约一到两个数量级。在 P91BN 中添加硼 (0.006 wt-%) 并控制氮含量 (0.011 wt-%) 导致比 P91 钢更好的蠕变断裂强度。使用Larson-Miller参数方法， 在P91BN钢的情况下，在873 K下评估10 ⁵ h寿命的蠕变断裂强度比P91钢提高了约33％。