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高强耐蚀重轨U68CuCr是国内新近研制开发的钢轨新品种,通过在Gleeble-1500热模拟试验机上对耐蚀重轨钢进行单道次压缩试验,测定了在不同变形温度、变形量和变形速率条件下的真应力-真应变曲线,分析了热变形参数对珠光体动态再结晶行为的影响。利用金相显微镜和扫描电镜观察了不同变形条件下空冷得到的珠光体显微组织,测定了珠光体片间距和珠光体球团等显微组织参数,分析了热变形参数对珠光体组织影响的规律。研究表明:变形温度升高、变形速率降低、变形量增大的条件下,利于耐蚀重轨钢动态再结晶的发生;当变形温度和变形量一定时,变形速率越低,发生动态再结晶的可能性越大,应力峰值和临界应变减小;发生动态再结晶后得到珠光体组织,其珠光体片层间距和珠光体球团尺寸比未发生再结晶得到的珠光体更细小。
High-strength corrosion-resistant heavy rail U68CuCr is a new type of rail recently developed in China. The single-pass compression test of corrosion-resistant heavy rail steel was carried out on a Gleeble-1500 thermal simulation test machine to measure the deformation rate and deformation rate under different deformation temperatures Under the conditions of true stress - true strain curve, analysis of the thermal deformation parameters of pearlite dynamic recrystallization behavior. The microstructure of the pearlite obtained by air cooling under different deformation conditions was observed by means of a metallographic microscope and a scanning electron microscope. The parameters of the pearlite and the pearlite were measured, and the influence of the thermal deformation parameters on the pearlite structure was analyzed law. The results show that the dynamic recrystallization of heavy rail steel is in favor of the dynamic recrystallization of heavy rail steel under the condition of increasing the deformation temperature, decreasing the deformation rate and increasing the deformation amount. When the deformation temperature and the deformation amount are constant, the lower the deformation rate, the dynamic recrystallization The larger the probability is, the smaller the stress peak and the critical strain become. The pearlite structure obtained after dynamic recrystallization has a finer pearlite size than the pearlite obtained without recrystallization.