通过室温拉伸、冲击试验、硬度测试、金相组织分析、扫描电镜及能谱分析等,对600℃超超临界锅炉用国产Super304H管材高温服役过程的微观组织和力学性能进行了试验分析.结果表明:与国产原始钢管相比,高温服役后国产Super304H管材的室温强度和硬度升高、塑性和韧性下降,焊接接头的强度、硬度、冲击韧性不断降低且明显低于同一服役时间的母材.服役30 000h以上后,管材的力学性能仍处于较高水平,基体组织稳定,晶粒未见长大,微观组织开始出现M23C6沿晶界呈链状分布的老化迹象.可见,国产Super304H管材组织状态良好,在目前600℃超超临界机组设计条件下可稳定运行,建议加强对国产Super304H管材焊接接头的金属监督. The microstructure and mechanical properties of the domestic Super304H pipe under 600 ℃ ultra-supercritical boiler service life under high temperature were tested by room temperature tensile test, impact test, hardness test, microstructure analysis, scanning electron microscopy and energy spectrum analysis. Results The results show that the strength and hardness of domestic Super304H pipe increase after service at high temperature, the plasticity and toughness of the pipe decrease. The strength, hardness and impact toughness of the welded joint decrease continuously and are obviously lower than the base metal of the same service time. Service more than 30 000h, the mechanical properties of the pipe is still at a high level, the matrix organization is stable, the grain did not grow up, the microstructure began to M23C6 along the grain boundary chain showed the signs of aging .Can be seen, domestic Super304H pipe tissue in good condition , Which can run stably under the current design conditions of 600 ℃ ultra-supercritical units. It is suggested to strengthen the supervision on the welded joints of domestic Super304H pipes.