大型H型钢控制冷却研究

发布时间：2018-07-11 10:41

本文选题：大型H型钢 + 喷雾冷却　；参考：《华北理工大学》2017年硕士论文

【摘要】：大型H型钢由于其优越的力学性能,在国民经济建设的各个方面得到了广泛的应用。H型钢由于断面形状复杂,在冷却过程中不可避免地出现温度分布不均匀的现象,使其存在断面温差,从而使H型钢内部出现残余应力,导致H型钢出现波浪、开裂等质量缺陷,严重影响了H型钢的机械性能和使用性能,特别是对于大型H型钢,问题尤其突出。本课题以规格为H300?300?15?10,材质为Q235的大型H型钢为研究对象,采用喷雾冷却方法对大型H型钢进行控制冷却。研究各冷却工艺参数对大型H型钢组织和性能的影响。利用Pro-E软件建立H型钢实体模型,并利用有限元软件ANSYS对H型钢的控制冷却过程进行有限元模拟。根据Q235钢的静态连续转变曲线(CCT曲线),确定有限元模拟和冷却实验时的开冷温度、终冷温度、冷却速度等参数。本文对不同的冷却方案进行有限元模拟,分析每个方案的H型钢温度分布情况,选择温差较小的一组做为最佳的控制冷却参数。课题组自行研制设计了一套适用于大型H型钢的喷雾冷却平台,根据Q235的CCT曲线和有限元模拟结果,制订不同的控制冷却方案,进行喷雾冷却实验。由于腹板薄,散热快,因此在进行冷却实验时主要针对翼缘进行喷雾冷却。对喷雾冷却后的H型钢进行金相组织和力学性能分析。研究不同冷却工艺参数对H型钢组织及力学性能的影响,选择最优的冷却参数。控制余热淬火时的喷雾冷却工艺参数,降低翼缘和腹板因自回火而产生较大的温差。从而实现对翼缘和腹板应力差的有效控制。降低大型H型钢内部的残余应力,并实现组织细化,提高H型钢的综合机械性能。
[Abstract]:Because of its superior mechanical properties, large H-section steel has been widely used in various aspects of national economic construction. Due to the complex section shape, the phenomenon of uneven temperature distribution is inevitable in the cooling process. The temperature difference of section makes the residual stress appear inside the H-section steel, which leads to the quality defects such as wave and crack, which seriously affect the mechanical properties and service performance of H-section steel, especially for the large H-section steel. The problem is particularly acute. In this paper, the large H section steel with the specification of H300, 300 and 1510 and the material of Q235 is taken as the research object. The spray cooling method is used to control the cooling of the large H section steel. The effect of various cooling process parameters on the microstructure and properties of large H section steel was studied. The solid model of H-section steel is established by using Pro-E software, and the controlled cooling process of H-section steel is simulated by finite element software ANSYS. According to the static continuous transformation curve (CCT curve) of Q235 steel, the open cooling temperature, final cooling temperature and cooling rate are determined in finite element simulation and cooling experiment. In this paper, different cooling schemes are simulated by finite element method, and the temperature distribution of H-section steel in each scheme is analyzed, and a group of small temperature difference is selected as the best controlled cooling parameter. Based on the CCT curve of Q235 and the finite element simulation results, a set of spray cooling platform suitable for large H-section steel has been developed. Different controlled cooling schemes have been worked out and the spray cooling experiments have been carried out. Because the web is thin and the heat dissipation is fast, spray cooling is mainly carried out for the flange in the cooling experiment. The microstructure and mechanical properties of H section steel after spray cooling were analyzed. The effects of different cooling process parameters on the microstructure and mechanical properties of H-section steel were studied and the optimum cooling parameters were selected. The process parameters of spray cooling during afterheat quenching are controlled to reduce the temperature difference between flange and web due to self tempering. Thus, the stress difference between flange and web can be controlled effectively. The internal residual stress of large H-section steel is reduced, the microstructure is refined, and the comprehensive mechanical properties of H-section steel are improved.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG142.1

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