某电厂一台型号为φ1200 mm×4500 mm球磨机为单进单出型。球磨机在长期使用过程中筒体在近法兰处出现裂纹,且有延伸趋势。经第一次修补,使用一段时间后裂纹再次沿原补焊位置出现。裂纹沿筒体厚度方向贯穿筒体,沿长度方向为350 mm。球磨机筒体材质为ZG270-500,筒体厚度为45 mm。 A power plant a model for φ1200 mm × 4500 mm ball mill into a single-out. Ball mill in the long-term use of the process of cracks in the flange near the flange, and there is an extension trend. After the first repair, use the crack again after a period of time along the original welding location. Cracks run through the barrel along the thickness of the barrel, along the length of 350 mm. Ball mill material for the ZG270-500, the cylinder thickness of 45 mm.