为揭示不同火灾环境下Q345 厚板组织和性能的变化规律,通过显微组织定量表征和硬度性能测试方法,分析了不同火灾环境对Q345 厚板铁素体含量及硬度分布规律的影响.结果表明:在相同受火温度下,Q345 厚板铁素体含量及硬度沿厚向的变化趋势不明显;而不同受火温度下,Q345 厚板相同测试点位置处的铁素体含量随温度的升高而下降,其硬度随温度的升高而增大.基于试验结果,分别建立了Q345 厚板VF-T和H-l-T预测模型,并揭示了VF-H相互影响关系,该模型可为火灾环境下Q345 厚板组织和性能的变化评价提供理论参考.
To reveal the variation law of microstructure and properties of Q345 thick plate under different fire en-vironment,the influence of different fire conditions on the ferrite phase content and hardness distribution of Q345 thick plate is analyzed by means of microstructure quantitative characterization and hardness testing.The results show that under the same fire temperature,the variation trend of ferrite phase content and hardness along the thickness direction of Q345 thick plate is not significant.However,under different fire temperatures,the ferrite phase content of Q345 thick plate at the same test point decreased while the hardness increased with the increas-ing temperature.Based on test results,the VF-T and H-l-T predictive models for ferrite phase content and hard-ness of Q345 thick plate are established,respectively.The interrelationship between VF and H is revealed,provi-ding a theoretical reference for evaluating the changes in microstructure and properties of Q345 thick plate under fire conditions.