铸辗复合成形法兰坯高温变形行为及加工图

发布时间：2018-02-24 12:42

  本文关键词： 铸辗复合成形 加工图 离心铸造 微观组织 辗扩参数　出处：《机械工程学报》2016年04期 　论文类型：期刊论文

【摘要】：环件铸辗复合成形工艺具有缩短工艺流程、高效和节能节材等优点,研究铸态环坯在铸辗复合成形工艺下的高温变形行为,揭示其组织演变机理,是实现材料在该成形工艺中成形与成性的关键。在不同变形条件下对砂型铸造和离心铸造Q235B法兰坯进行高温压缩试验,分析其流变应力的变化,推导出二者的本构方程。综合变形温度和应变速率对材料微观结构与性能的影响,建立基于动态材料模型的加工图。试验结果表明:二者的流变应力随着应变速率的增加和变形温度的降低而增大。离心铸造法兰坯的流变应力较低,动态再结晶易于发生,且功耗效率值及其变化幅度都要大于砂型铸造,表明了其显微组织变化剧烈,演变更加充分。结合二者的热加工图及其识别出的典型区域显微组织,获得了适合该法兰坯辗扩工艺的热力参数范围,离心铸造可为法兰坯铸辗复合成形工艺提供高质量的铸坯。
[Abstract]:The compound forming process of ring casting and rolling has the advantages of shortening technological process, high efficiency and saving energy, etc. The deformation behavior of as-cast ring billet at high temperature is studied, and the mechanism of microstructure evolution is revealed. It is the key to realize the formability and formability of the material in the forming process. The high temperature compression test of sand mold casting and centrifugal casting Q235B flange billet is carried out under different deformation conditions, and the change of rheological stress is analyzed. The effects of deformation temperature and strain rate on the microstructure and properties of the materials are derived. The experimental results show that the rheological stress increases with the increase of strain rate and the decrease of deformation temperature. The flow stress of centrifugal casting flange billet is low and dynamic recrystallization is easy to occur. The value of power efficiency and its variation range are larger than those of sand casting, which indicates that the microstructure changes sharply and evolves more fully. The range of thermal parameters suitable for the flange billet rolling process was obtained. Centrifugal casting can provide high quality billet for the flange billet casting and rolling compound forming process.
【作者单位】： 太原科技大学材料科学与工程学院;
【基金】：国家自然科学基金重点(51135007);国家自然科学基金(51174140,51205270) 高等学校博士点优先发展计划(20111415130001)资助项目
【分类号】：TG24;TG306
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本文编号：1530284