为验证建筑结构抗震耐蚀耐火钢Q460 FRW抗低温冲击性能的设计要求，用SANS型摆锤式冲击试验机对Q460 FRW钢开展抗低温冲击韧性试验，并进行了试样断口微观形貌的分析。根据GB/T 229—2007《金属材料夏比摆锤冲击试验方法》，在-20、-40、-60℃环境温度下对10、28 mm两种规格Q460FRW钢试件进行抗低温冲击试验，获得了冲击能值AkV，得到了两个系列Q460FRW钢在各低温点的冲击强度随温度的变化规律，并对试件进行了室温和低温拉伸强度、屈服强度和延伸率试验。同时，用扫描电镜在放大1 000倍下对两种规格Q460FRW钢试件分析冲断后的断口微观形貌。试验结果表明：Q460 FRW钢在低温环境下能保持较高的冲击功和良好的冲击韧性。同时，在-20，-40，-60℃的低温环境下，冲击韧性随温度的降低而略有提高。两个系列Q460 FRW钢的纵向冲击功值均大于34 J，符合GB/T 19879—2005《建筑结构用钢板》的要求，在低温下满足抗冲击性能设计要求。扫描电镜观测分析表明，在冲击拉伸过程中，裂纹从试样中心的纤维区向外扩展，在裂纹区附近发生了较大的塑性变形，形成了较大的剪切缺口，表明它们都是韧性的，且从扫描电镜图中未看出断裂韧窝的大小和深度具有显著的差异。
In order to verify the design requirements of low temperature impact resistance of Q460FRW steel, its impact toughness at low temperature was tested with SANS pendulum impact testing machine, and the fracture morphology of samples was analyzed. According to GB/T 229—2007 Metallic Materials Charpy Pendulum Impact Test Method, low temperature impact test was carried out on Q460FRW steel specimens of 10 mm and 28 mm at - 20, - 40, - 60 ℃ ambient temperature. The impact energy value AkV was obtained, and the experimental curve of impact strength with temperature was plotted from two series of Q460FRW steel specimens at each low temperature point. The tensile strength, yield strength and elongation of FRW steel at room temperature and low temperature were tested. Scanning electron microscope (SEM, at 1 000 magnification) was used to analyze the fracture morphology of Q460FRW steel specimens in two standard sizes after impact fracture. The results shown that Q460FRW steel can maintain high impact energy and good impact toughness at low temperature. At the same time, the impact toughness increases slightly with the decrease of temperature at -20, - 40, - 60 ℃. The longitudinal impact energy values of the two series Q460FRW were greater than 34 J, according with the requirements of GB/T 19879—2005 Steel Plates for Building Structures, and meeting the design requirements of impact resistance at low temperature. SEM observation and analysis shown that the crack propagates outward from the fiber area in the center of the specimen during impact tension, and a large plastic deformation occurs near the crack area, forming a large shear notch, which indicated that were ductile. There is no significant difference in the size and depth of the fracture dimple from SEM.