钢的半固态单轴压缩变形规律  

Deformation Behavior of Semisolid Steel during Uniaxial Compression

作　　者：杨卯生[1] 李士琦[1] 毛卫民[2] 钟雪友[2] 

机构地区：[1]北京科技大学冶金学院,北京100083 [2]北京科技大学材料学院,北京100083

出　　处：《钢铁研究学报》2005年第2期24-29,共6页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(59995440)

摘　　要：用Gleeble 1500热模拟实验机研究了不同变形速率、不同变形温度以及不同变形量下60Si2Mn钢的半固态应力与应变的变化规律,并通过金相观察分析了压缩变形后钢的半固态显微组织。结果发现钢的半固态压缩变形特征为:随着变形温度的不同呈粘塑性流动;在不同的变形速率下,初始变形阶段的应力变化是基本一致的,即半固态的钢先呈现出线弹性的变形响应,随后呈现出不同软化程度的粘性流动变形响应;变形量对钢的半固态变形特征影响显著。在适宜的温度及变形量范围内,半固态的钢呈粘性流动。笔者认为:半固态的钢因其特殊的组织特点,会形成疏松且不稳定的晶粒聚集结构。在外界作用下,该聚集结构将被破坏,从而导致钢的半固态浆料的表观粘度下降,即呈现出“剪切变稀”的触变特性。The deformation behavior of semisolid 60Si2Mn at different deformation temperatures, deformation rate and deformation volume were studied using Gleeble-1500 thermal simulator. The results showed that the deformation of semisolid steel specimen is characteristic of viscous flow and plastic flow. The deformation volume has great effect on deformation behavior of semisolid steel, and the deformation of semisolid steel is characteristic of viscous flow within the desired deformation and temperature range. For different deformation rate, the material shows elastic deformation contact in the initial compression stage, then it shows viscous flow during the decrease of deformation stress. It was considered that the unstable structure of grain agglomeration is formed in semisolid steel due to the special spherical structure. The desintegration of this structure during the compression results in the decrease of apparent viscosity, so the thixotropic behavior known as shear thinning occurs.

关 键 词：变形规律 单轴压缩 60SI2MN钢 热模拟实验机 变形速率 变形温度 变形特征 变形响应 粘性流动 聚集结构 半固态浆料 变形量 变化规律 显微组织 压缩变形 金相观察 塑性流动 应力变化 初始变形 组织特点 外界作用 表观粘度 

分 类 号：TG249[金属学及工艺—铸造]