邹县发电厂是一座大型矿口燃煤电站,其三期扩建工程安装2台600MW机组,该机组锅炉是美国FWWC设计生产的亚临界、一次中间再热、自然循环Ⅱ型布置、燃煤汽包炉。汽轮发电机由东方汽轮机厂和日立公司联合制造,汽轮机为亚临界、单轴三缸四排汽凝汽式汽轮机。 由于600MW机纽中厚壁管道较多,给焊接及检验带来了一定的困难。在对主蒸汽焊口进行根部探伤时,依照GB/T12605—90中的规定,环缝AB级透照进度比K值不大于1.1,通过计算至少需要透照8张底片,劳动强度大,效率也很低。进行γ源射线探伤,胶片灰雾度较大,对比返差较少,且发现危险能力较差。因此,射线探伤方法不能很好地适应对厚壁对接焊缝进行根部探伤。 Zouxian Power Plant is a large-scale mine mouth coal-fired power station, the third phase of the expansion project to install two 600MW unit, the unit is designed and manufactured by the United States FWWC subcritical, an intermediate reheat, natural circulation Ⅱ layout, coal gas Including furnace. Turbine generators are jointly manufactured by Dongfang Steam Turbine Works and Hitachi Ltd. The turbines are subcritical, single-shaft, three-cylinder four-row steam condensing steam turbines. As more thick-walled New Hampshire 600MW machine to the welding and testing has brought some difficulties. In the root of the steam welding mouth of the root flaw detection, GB / T12605-90 in accordance with the provisions of the ring seam AB level transillumination progress than the K value of not more than 1.1, through the calculation of the need to pass through at least 8 negatives, labor-intensive, efficient Very low. For γ source ray flaw detection, the film has a higher degree of fogging, less contrast and less risk, and found less dangerous. Therefore, the ray inspection method is not well adapted to the root flaw detection of thick butt welds.