图5.19为Q690NHH耐蚀耐火钢焊接接头各部位微观组织。其中焊缝及焊缝重热区金相组织均为贝氏体；HAZ过热区金相组织为粒状贝氏体；HAZ正火区金相组织为贝氏体；HAZ不完全正火区金相组织为贝氏体。  

Figure 5.19 shows the microstructure of each part of the Q690NHH corrosion-resistant and fire-resistant steel welded joint. The metallographic structure of the weld and the reheat zone of the weld is bainite; the metallographic structure of the HAZ overheating zone is granular bainite; the metallographic structure of the HAZ normalizing zone is bainite; the metallographic structure of the HAZ incomplete normalizing zone The organization is bainite.