某300 MW机组回转式空气预热器仓格板发生大面积开裂, 开裂部位主要位于径向隔板与中心筒、径向隔板与周向隔板角焊缝焊趾部位。从理化性能、结构和外在因素等方面对该空气预热器仓格板开裂原因进行了分析。结果表明:焊接工艺不当造成的热裂纹和焊接缺陷是引起该空气预热器仓格板开裂的主要原因。

A wide range of cracking was found on the partition plates of rotary air preheaters in a 300 MW unit, and the cracking was mainly located in the toe area of fillet welds between the radial partition plates and the central cylinders, and also between the radial partition plates and circumferential partition plates. The reasons for the cracking were analyzed from the aspects of physical and chemical properties, structure and external factors. The results show that the cracking of the preheater partition plates was mainly caused by the thermal cracks and welding defects due to the improper welding technology parameters.