建筑用耐火钢组织与性能的研究

对两种工业试制耐火钢的力学性能和微观组织进行了研究。通过回火处理,研究了回火温度对微观组织的影响,同时进行了金相分析,探讨了耐火钢的高温强化机理。试验结果表明:建筑用耐火钢的室温显微组织为多边形铁素体、少量珠光体和少量粒状贝氏体的混合组织;细小、弥散分布的M-A(Martensite-Austenite)组织是建筑用耐火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钢的高温性能;thermo-calc热力学软件计算结果表明:Mn、Mo、Cr、V等合金元素能大量熔于渗碳体中,形成合金渗碳体,对阻止高温回火组织粗化,保持良好的高温性能有较大影响。

A STUDY ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF FIRE-RESISTANT STEELS

The microstructure and mechanical properties of two industrial trial-produced fire-resistant steels were investigated. By tempering, the effects of tempering temperature on microstructure were researched. At the same time, high-temperature strengthening mechanism of fire-resistant steels was also explored.The microstructure of a building fireproof steel is the one of polygonal ferrite,pearlite and martensite. The fine distribution of M-A(Martensite-Austenite) and alloys elements effecting the microstructure are the main factors of keeping significant high-temperature properties on fire-resistant steels for building.In high temperature, the stable microstructure is propitious to evaluate high-temperature properties of fire-resistant steels. The Thermo-calc calculation indicates that manganese,molybdenum and chromium can dissolve in cementite. It can make good effects on preventing microstructure from coarsening at high-temperature and keeping well high-temperature properties.