基于铸态Q235B环件热辗扩成形工艺数值模拟研究

发布时间：2018-05-12 01:01

  本文选题：铸态Q235B + 热辗扩成形　； 参考：《太原科技大学》2015年硕士论文

【摘要】：随着大型环件、法兰在工业、航天、核电等高科技等领域的广泛应用,对环件的需求量日益增多,对环件性能、生产工艺的要求越来越严格。因此,节约能源、降低成本、提高质量和生产率已成为环件生产和装备制造业发展的必然趋势。金属环件短流程铸辗复合精确成形工艺,在传统环形零件生产工艺的基础上进行突破性地改进,具有流程短、节能、节材、高效、低成本、环保等显著优势。本文以离心与砂型铸坯Q235B钢为研究对象,采用理论分析方法、数值模拟方法和对比分析方法,从宏观上研究了金属环件铸辗复合成形过程中成形参数对环件组织和性能的影响规律,从微观上研究了成形参数对热变形再结晶体积分数、再结晶晶粒尺寸及平均晶粒尺寸的影响规律。研究结果表明:(1)热辗扩成形中,芯辊的进给速度越大,等效塑性应变分布越来越均匀,温度场变形更加均匀,辗扩力也越大。芯辊进给速度为变速时,等效应变和温度场的最大值减小和最小值加大,分布更加均匀,辗扩初期辗扩力增加较为缓慢。通过对离心铸坯与砂型铸坯宏观变形对比分析,在相同辗扩参数下,离心铸坯比砂型的等效塑性应变和温度场分布更加均匀,但辗扩力要高。(2)随着芯辊进给速度的变大,动态再结晶体积分数变小,且更加均匀,动态再结晶晶粒尺寸稍有变小,但分布越来越均匀,平均晶粒尺寸分布也越均匀。芯辊进给速度采用加速度变速时,其动态再结晶体积分数、再结晶晶粒尺寸、平均晶粒尺寸分布比匀速更加均匀。(3)结果分析可得,在满足环件辗扩成形设备的使用条件下,采用Q235B离心铸坯,芯辊进给速度以(先以加速度2?/1.0 smma加速运动,达到速度V=1.6mm/s,再匀速进给34s,最后再以加速度为2??/1.0 smma运动,减速到零)的变速,初始温度为1150℃,可以使环件辗扩变形更加均匀,晶粒更加细化,辗扩质量和生产效率都达到理想的目标。
[Abstract]:With the wide application of large ring, flange and other high-tech fields, such as industry, aerospace, nuclear power, etc., the demand for ring parts is increasing day by day, and the requirements for the performance and production process of ring parts are becoming more and more strict. Therefore, saving energy, reducing cost, improving quality and productivity has become an inevitable trend in the development of ring production and equipment manufacturing industry. Based on the traditional annular parts production technology, the metal ring short process casting and rolling compound precise forming process is improved by a breakthrough, which has the advantages of short process, energy saving, material saving, high efficiency, low cost, environmental protection and so on. In this paper, centrifugal and sand billet Q235B steel is taken as the research object, theoretical analysis method, numerical simulation method and comparative analysis method are used. The influence of forming parameters on the microstructure and properties of the ring in the process of casting and rolling composite forming of metal ring is studied macroscopically, and the integral number of the forming parameters on the recrystallization volume of hot deformation is studied from the microscopic point of view. The effect of recrystallization grain size and average grain size. The results show that the larger the feed speed of the core roll, the more uniform the equivalent plastic strain distribution, the more uniform the temperature field deformation and the greater the rolling force in the hot rolling forming. When the feed speed of core-roller is variable, the maximum value and minimum value of equivalent strain and temperature field decrease, the distribution is more uniform, and the rolling force increases slowly at the beginning of rolling. Through the comparative analysis of macro deformation of centrifugal and sand casting billet, under the same rolling parameters, the distribution of equivalent plastic strain and temperature field of centrifugal billet is more uniform than that of sand mold, but the rolling force is higher than that of sand mold, but the rolling force increases with the feed speed of core roll. The dynamic recrystallization volume integral number becomes smaller and more uniform, and the dynamic recrystallization grain size is slightly smaller, but the distribution is more and more uniform, and the average grain size distribution is more uniform. The dynamic recrystallization volume integral number, recrystallized grain size and average grain size distribution are more uniform than uniform velocity when the feed speed of core-roller is changed by acceleration. The results can be obtained under the condition that the ring rolling forming equipment can be used. Using Q235B centrifugal casting billet, the feed speed of core roll is changed to 1150 鈩，

本文编号：1876402