Abstract In the present endeavor, a Gleeble thermo-mechanical simulator has been used to simulate subzones of the heat-affected zone (HAZ) of boron-free P91 and boron-modified P91B steels to investigate the influence of boron on microstructure and mechanical properties. The prior austenite grain (PAG) size remained similar to that of parent metal in the fine-grained heat-affected zone (FGHAZ) and inter-critical heat-affected zone (ICHAZ) of P91B steel. The microhardness value of simulated specimens, including parent metals was observed to be similar. But impression creep resistance of boron-containing steel was significantly higher than that of the boron-free steel. The presence of boron decreased precipitates size and increased fraction of low energy Σ3 coincident-site lattice (CSL) boundaries that attributed to improvement of creep resistance. However, there was a slight reduction in solid solution hardening due to increased area fraction of precipitates in parent metal and simulated specimens of boron-containing steel. Hindering of alloy element partitioning during impression creep of P91B-ICHAZ was observed, which was possibly due to the presence of boron in soluble form in the iron matrix and the segregated form on grain and sub-grain boundaries (SGBs). Further, the addition of boron was observed to retard M23C6 precipitate coarsening in the P91B-ICHAZ in comparison to its P91 version.

中文翻译：

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硼对P91钢Gleeble模拟热影响区组织和力学性能的影响

摘要 在目前的努力中，Gleeble 热机械模拟器已被用于模拟无硼 P91 和硼改性 P91B 钢的热影响区 (HAZ) 子区，以研究硼对微观结构和机械性能的影响。在 P91B 钢的细晶热影响区 (FGHAZ) 和临界间热影响区 (ICHAZ) 中，原始奥氏体晶粒 (PAG) 尺寸与母金属的尺寸保持相似。观察到模拟试样（包括母金属）的显微硬度值相似。但含硼钢的压痕抗蠕变性明显高于无硼钢。硼的存在降低了析出物尺寸并增加了低能量 Σ3 重合点晶格 (CSL) 边界的比例，这归因于抗蠕变性的提高。然而，由于母材和含硼钢模拟试样中析出物的面积分数增加，固溶硬化略有减少。观察到在 P91B-ICHAZ 压痕蠕变期间合金元素分配受阻，这可能是由于铁基体中存在可溶形式的硼以及晶粒和亚晶界 (SGB) 上的偏析形式。此外，与 P91 版本相比，观察到添加硼可以延缓 P91B-ICHAZ 中 M23C6 沉淀物的粗化。这可能是由于铁基体中存在可溶形式的硼以及晶粒和亚晶界 (SGB) 上的偏析形式。此外，与 P91 版本相比，观察到添加硼可以延缓 P91B-ICHAZ 中 M23C6 沉淀物的粗化。这可能是由于铁基体中存在可溶形式的硼以及晶粒和亚晶界 (SGB) 上的偏析形式。此外，与 P91 版本相比，观察到添加硼可以延缓 P91B-ICHAZ 中 M23C6 沉淀物的粗化。