The work described the effect of the grain refinement in virgin P92 steel plate on the microstructural and mechanical behavior of the P92 welded joint. The as-received P92 steel plate was subjected to varying heat-treatment, i.e., conventional heat treatment (CNT) and double normalized heat treatment (DNT) to refine the grain structure. The DNT is mainly done for the grain refinement in the as-received P92 steel plate. The autogenous gas tungsten arc welding (GTAW) process was utilized to prepare the P92 steel welds joint. Four set of the welds joint were prepared, two by using the CNT plate, termed as AW1 and two by using the DNT plate, termed as AW2. The welded plate has been subjected to heat treatment at 760 °C for 3 h (T1, T2) for both the conditions to stabilize the microstructure of weldments, i.e., tempering of the fresh martensite. The grain growth, particle size, and particle distribution in P92 weldments have been studied. For mechanical characterization, tensile tests, hardness tests and Charpy toughness tests (CTT) have been carried out. Soft δ ferrite formation was observed in weld fusion zone (WFZ) and coarse-grained heat-affected zone (CGHAZ) for AW and T condition and formation is attributed to high heat input and presence of the ferrite stabilizer like W and Mo. Heterogeny in microstructure and mechanical properties was measured across the weldments for AW condition and get minimized as a result of the PWHT. The average hardness for WFZ was measured 363 and 358 HV for AW1 and AW2 conditions, respectively. The difference in the hardness of WFZ can be neglect. The peak hardness of CGHAZ was measured at 358 and 397 HV for AW1 and AW2, respectively and it is attributed to the solid solution strengthening mechanism. The variation in hardness along the welded joint was reduced to a minimum level as a result of the heat treatment. The AW 2 welds joint showed maximum tensile strength of 943 MPa and get reduced drastically after the heat-treatment (T2) (700 MPa) but still showed a higher value as compared to T1 (602 MPa). A significant improvement in tensile strength without any loss in ductility was obtained for the welds joint prepared using the DNT plate as compared to CNT plate.

这项工作描述了原始P92钢板晶粒细化对P92焊接接头的组织和力学行为的影响。对收到的P92钢板进行不同的热处理，即常规热处理（CNT）和双重规格化热处理（DNT），以细化晶粒组织。DNT主要用于按原样生产的P92钢板中的晶粒细化。利用自生气体钨极电弧焊（GTAW）工艺制备P92钢焊缝。准备了四套焊接接头，其中两套使用称为AW1的CNT板，两套使用称为AW2的DNT板。在两种用于稳定焊件微观结构的条件（即新鲜马氏体回火）的条件下，均应在760°C下对焊板进行3 h的热处理（T1，T2）。研究了P92焊件中的晶粒长大，粒径和颗粒分布。为了进行机械表征，已经进行了拉伸测试，硬度测试和夏比韧性测试（CTT）。在AW和T条件下，在焊接熔合区（WFZ）和粗粒热影响区（CGHAZ）中观察到软δ铁素体形成，其形成归因于高热量输入以及铁素体稳定剂（如W和Mo）的存在。在AW条件下测量了整个焊件的显微组织和力学性能，并由于PWHT而使其最小化。在AW1和AW2条件下，WFZ的平均硬度分别为363和358 HV。WFZ硬度的差异可以忽略不计。对于AW1和AW2，在358和397 HV下测量了CGHAZ的峰值硬度，分别归因于固溶强化机制。由于热处理，沿焊接接头的硬度变化降低到最小水平。AW 2焊接接头的最大抗拉强度为943 MPa，经过热处理（T2）（700 MPa）后急剧降低，但与T1（602 MPa）相比仍显示出更高的值。与CNT板相比，使用DNT板制备的焊接接头的抗拉强度得到了显着提高，而延展性没有任何损失。AW 2焊接接头的最大抗拉强度为943 MPa，经过热处理（T2）（700 MPa）后急剧降低，但与T1（602 MPa）相比仍显示出更高的值。与CNT板相比，使用DNT板制备的焊接接头的抗拉强度得到了显着提高，而延展性没有任何损失。AW 2焊接接头的最大抗拉强度为943 MPa，经过热处理（T2）（700 MPa）后急剧降低，但与T1（602 MPa）相比仍显示出更高的值。与CNT板相比，使用DNT板制备的焊接接头的抗拉强度得到了显着提高，而延展性没有任何损失。