1999年1月份,对我厂300MW机组的4#炉进行工作水压试验时,发现过热器一、二、三级减温器上的定位螺栓、支撑螺栓、固紧螺栓角焊缝存在不同程度的多点泄漏。一、二、三级减温器泄漏点分别为17个、26个、34个,即全部螺栓角焊缝均有泄漏,经检查螺栓角焊缝上有大量细小裂纹,打磨后发现螺栓与螺纹连接处有铁锈、铁屑、夹渣等缺陷。3#炉(300MW机组)在1999年5月份大修中过热器减温器的22只螺栓角焊缝也有上述情况。 In January 1999, working pressure test of 4 # furnace of 300MW unit in our factory showed that there are different degrees of fillet welds, supporting bolts and fastening bolts in the first, second and third desuperheaters of the superheater More leaks. One, two, three desuperheater leak points were 17, 26, 34, that is, all the fillet weld fillets have leaks, the inspection fillet weld a large number of small cracks, polished and found the bolt and thread Connection rust, iron filings, slag and other defects. The above situation was also observed for the 22-bolt fillet welds of the 3 # furnace (300MW unit) overheating the superheater desuperheater in May 1999.