【摘要】 对工业试制耐火H型钢的力学性能和微观组织进行了研究。分析了回火温度及时间对微观组织的影响,探讨了耐火钢的高温强化机理。结果表明,建筑用耐火H型钢在室温时的显微组织为多边形铁素体、少量珠光体和少量马氏体的混合组织,细小、弥散分布的马氏体组织是建筑用耐火H型钢保持良好高温性能的一个主要原因。高温下良好的组织稳定性有利于提高耐火H型钢的高温性能。thermocalc热力学软件计算结果表明,Mn、Mo、Cr等合金元素能大量固溶在渗碳体中,形成合金渗碳体,有利于阻止高温回火组织粗化,保持良好的高温性能。更多还原

【Abstract】 The mechanical properties and microstructure of industrial trial-produced fire-resistant H-Beam steel were investigated.The effect of tempering temperature and time on microstructure was analysed.The high-temperature strengthening mechanism of fire-resistant steels was also disscussed.The results show that the multiphase microstructure consisting of polygonal ferrite,pearlite,martensite are the basic microstructure of the steels.The fine and dispersion distribution martensite is the main factor for the steels to keep good high-temperature properties.The stable microstructure at high temperature helps to enhance the high-temperature properties of the steels.The thermo-calc calculation indicates that manganese, molybdenum, chromium can dissolve in cementite, which prevents the microstructure from coarsing at high-temperature and consequently keep good high-temperature properties.更多还原