用热模拟机多轴变形系统研究超细组织结构

Study on Ultrafine-grain Structure by Multi-axis Deformation Test in Simulator

本文利用Gleeble-3800热模拟机多轴大变形系统，对管线钢进行了几组不同热变形制度的多道次大应变热压缩试验，配合控轧后冷却速度，得到了1～2μm的超细晶组织。通过金相显微镜观察，扫描电镜观察及透射电镜分析，研究其微观组织形态、精细结构特征、析出相特征，从中找出不同热变形参数变化对其微观组织的影响及析出物析出的影响规律。

The multiple pass deformation testing of pipeline steel have been carried out on the Gleeble-3800 simulation machine. Ultrafine-grain structure on the order of 2μm or less in diameter have been obtained at different forming and cooling conditions. The optical microstructure was characterized. Transmission electron microscopy analysis were carried out to investigate the morphology of ultrafine-grain and to characterize the fine structure and precipitation. The influence of varying hot deformation conditions on the structure and precipitation have been studied.