预变形量对SUPER304H钢管性能的影响
Effect of Pre-deformation on Properties of SUPER304H Tube
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摘要: 对超(超)临界锅炉用SUPER304H耐热钢管进行预变形量分别为0, 15%, 20%的预变形, 再在700 ℃时效100, 1 000, 5 000 h, 研究了预变形量对时效前后钢管性能的影响。结果表明: 随预变形量的增加, 变形钢管的室温强度、硬度和短时高温强度均上升, 塑性下降明显, 但仍具有一定塑性; 时效钢管的硬度变化主要取决于预变形量而非时效时间, 但时效会降低变形钢管的短时高温强度; 不高于20%的预变形量对SUPER304H钢管的持久性能影响有限。Abstract: The heat-resistant steel tube SUPER304H used for ultra-supercritical (USC) boiler was pre-performed with deformations of 0,15% and 20%, and then to aged at 700 ℃ for 100, 1 000, 5 000 h. The effets of pre-deformation on properties of the tubes before and after aging were studied. The results show that room temperature strength, hardness and short-term high temperature strength of the deformed tubes increased with the increase of pre-deformation, but the plasticity reduced sharply with a certain value retained. The hardness changes of aged tubes mainly depended on pre-deformation instead of aging time, however, its short-term high temperature strength was deceased by aging treatment. The pre-deformation less than 20% had limited affect on the SUPER304H tubes′ creep rupture properties.