研究了某造纸厂2台分别服役62 a和43 a的铸铁烘缸不同位置的显微组织和力学性能。结果表明：2台烘缸缸体及端盖均无明显的表面缺陷和裂纹缺陷，基体组织均为无明显球化的珠光体，石墨片的尺寸和分布均主要为A型，服役62 a烘缸前端盖和服役43 a烘缸后端盖的石墨片长度均较长；2台烘缸缸体和端盖的硬度均满足标准要求；除服役62 a烘缸前端盖的抗拉强度低于标准外，2台烘缸其余位置的抗拉强度均满足标准要求，服役62 a烘缸前端盖和服役43 a烘缸后端盖的抗拉强度明显较其他位置的低；2台超长年限服役烘缸在0.22 MPa的最高工作内压载荷下仍具有足够的强度。

The microstructure and mechanical properties at different positions of the two cast iron dryers in a paper mill after service for 62 a and 43 a were studied. The results show that there was no obvious surface defects and crack defects on the cylinder and end cover of the two dryers. The microstructure of substrate was pearlite without obvious spheroidization, and the size and distribution of the graphite sheets were mainly A type. The length of the graphite sheet of the front end cover of the dryer after service for 62 a and the rear end cover of the dryer after service for 43 a was relatively long. The hardness of the cylinder and the end cover of the two dryers all met the standards. The tensile strength of the front end cover of the dryer after service for 62 a was lower than the standard requirements, while those of the other positions of the two dryers all met the standard requirements. The tensile strength of the front end cover of the dryer after service for 62 a and the rear end cover of the dryer after service for 43 a was obviously lower than that of other positions. Both the two dryers still had sufficient strength under the maximum working internal pressure load of 0.22 MPa.