【作者】 贺静；

【导师】 刘锦云； 李聪；

【作者基本信息】 西华大学 ， 材料科学， 2006， 硕士

【摘要】 钢结构作为现代建筑的重要结构形式,代表了当今建筑结构发展的新潮流。但钢结构建筑存在一个致命的缺点,就是防火性能差。为了防止火灾给钢结构建筑造成灾难性破坏,确保人员、财产的安全,对建筑用结构钢提出了新的要求,耐火钢正是为了适应这一发展趋势而产生。随着建筑行业对钢结构建筑的防火、抗震等安全性能的要求日趋严格,在建筑行业专用的抗震、耐火钢板必将取代普通钢板,同时也必将带动国内高层钢结构建筑事业的发展。开发研制符合国际先进标准的建筑用耐火钢对促进我国建筑用钢的发展具有重要意义。 微观组织和合金元素是决定材料性能的主要因素。为了探索建筑用耐火钢性能与微观组织和合金元素的关系,本论文选用了四种工业试制的耐火钢,对它们进行了力学性能检测及金相、SEM形貌分析,研究了合金元素对微观组织的影响,探讨了微观组织与耐火钢力学性能之间的关系。 实验结果表明:试验用耐火钢的室温力学性能优于普通建筑用钢,满足普通建筑用钢的标准要求。高温时的屈服强度都大于250Mpa,高温屈服强度对室温屈服强度的比值(σ_s(600℃)/σ_s(室温)以下简称为屈服强度比值)大于2/3,满足建筑用耐火钢的标准要求。由于四种工业试制的耐火钢YR(σ_s/σ_b)≤0.80,所以它们具有高的抗震性能。Mo、Nb、V、Ti对于耐火钢都是有益合金元素,对提高耐火钢的高温力学性能均有明显作用。试验用耐火钢保持良好高温性能的显微组织更多还原

【Abstract】 Steel structure is a representative of the modernistic constructure, but which have a fatal restriction of fireproofing. Therefore, there was an increasing demand for eliminating or restricting fire-resistant coating. The fire-resistant steel meets to the needing.Microstructure and alloy elements are the major factors to determine material properties. In order to probe in the relationship between microstructure and alloy elements with the fire-resistant steels’properties, and offer to a reference to the fire-resistant steel development in microstructure and alloy elements design. This paper adopts to industrial trial-produced fire-resistant steels. The mechanical properties and microstructure of the industrial trial-produced fire-resistant steels was investigated. By tempering, the effects of alloyed elements on microstructure were investigated, the dependence of microstructure on fire-resistant steels of properties was discussed.The testing result indicate: YS ration (%) ≥ 2/3(YSration(%)= σ_s(600℃)/σ_s(room-temperature)), YR(%)(σ_s/σ_b) ≤ 0.80. Each of fire-resistant steel’s elevated temperature strength accordes with the Building Standards of the fire-resistant steels.The fire-resistant steels for buildings meet increasing steel’s elevated-temperature strength while assuring earthquake resistance, weldability and other properties betterthan those of conventional steels for buildings.lt has found that multiphase microstructure consisting of polygomal ferrite, pearlite, grain banite is the basic microstructure of fire-resistant steels. The fine distribution of M-A island is a mostly factor of keeping significant elevated temperature properties and low yield ratio on fire-resistant steels for building. At elevated temperature, the stable microstructure is propitious to evaluate high-temperature properties of fire-resistant steels. At the same time, alloy elements: molybdenum, chromium, niobium and titanium are profitable alloy elements.更多还原