权国政,石彧,赵磊,毛远平,周杰

• 1:重庆大学材料科学与工程学院

摘要(Abstract)：

通过对挤压态42CrMo高强钢在不同温度和应变速率下的热压缩实验获得真应力-应变曲线,作为研究其高温动态再结晶行为的底层数据。基于d#/dε-#曲线,识别了真应力-应变曲线上能表征动态再结晶演变过程的特征点:临界应变εc,峰值应变εp及最大软化速率应变ε*。引入表征晶体动力学的双曲正弦模型,通过线性回归求解得到动态再结晶激活能Q,建立流变应力本构方程。设计无量纲参数Z/A,对已修正的Avrami方程作线性回归分析,表征了不同变形条件对挤压态42CrMo钢动态再结晶体积分数演变的影响,并详细描述了动态结晶对应力软化的影响。结果表明:在高应变速率下,发生剧烈的软化后趋于稳定;在低应变速率条件下,出现硬化和软化的周期性循环。

关键词(KeyWords)： 动态再结晶;临界应变;流动应力;高强度钢

Abstract:

Keywords:

基金项目(Foundation): 科技部国家重大专项项目(G09003.8-1);; 重庆市重大科技攻关项目(cstc2009aa3012-1);; 中央高校基本科研业务费资助基金(CDJXS11131147);; 重庆大学大型仪器设备开放基金(2011063014)

作者(Author): 权国政,石彧,赵磊,毛远平,周杰

DOI: 10.13289/j.issn.1009-6264.2012.10.029

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