我厂是一个调频厂,锅炉负荷变化很大,因此减温器进水调节频繁。3炉是上锅五九年出厂的35吨/时抛煤式链条炉。自六○年投产使用已有二十二年之久。减温器为表面式。管板和钢管束长期在频繁的温度变化下工作,由此产生的交变应力很大。近年来管板开裂,钢管束泄漏,虽然过去采取补焊措施,但由于补焊技术不当,补焊后又未热处理,因此越补裂纹 I plant is a FM plant, the boiler load varies greatly, so frequent desuperheater water regulation. 3 furnace is a 35 tons / hour coal-fired chain furnace on the pot in 1979. It has been in use for more than 22 years since it was put into operation in 1960. Desuperheater for the surface. Tube sheets and tubes have long been subjected to frequent temperature changes, resulting in large alternating stresses. In recent years, tube sheet cracking, steel tube bundle leakage, although in the past to take measures to repair welding, but due to improper repair welding, repair welding after no heat treatment, so more crack