T91钢焊缝热影响区的模拟试验研究

A Simulation Study of T91 Steel Weld HAZ

利用箱式电阻炉制备了T91钢焊缝HAZ不同区域的模拟试样,用拉伸力学试验机、持久试验机和显微镜等设备测试和分析了模拟试样的常温力学性能、时效力学性能、特选区域的持久寿命。结果表明:HAZ中温度略高于A_(C1)区域存在拉伸强度和硬度的弱化区;HAZ中优先发生持久断裂的位置随着试验温度和应力水平而改变,何处优先发生持久断裂,取决于所施加的温度和应力,并且不同的温度均对应存在一个固有的临界应力。在相同的温度条件下,试验应力高,强度和硬度弱化区域的持久寿命最短;试验应力低,略高于A_(C3)区域的细晶区持久寿命最短;这种现象随着试验温度的升高更加明显。

T91 steel simulation samples at different areas of weld HAZ prepared by chamber electric furnace are tested and analyzed the room temperature and aging mechanical properties and creep rupture life of selected areas by tensile mechanical testing machine, durable tester and microscope. The result shows that there is a weaken zone slightly higher than Ac1 tem- perature in HAZ where the tensile strength and hardness are lower. Priority fracture position in the HAZ changes with the test temperature and stress level. There is an inherent critical stress at different temperatures. At the same temperature condition, the creep rupture life of strength and rigidity weakening zone is shortest with high test stress. With low test stress, the creep rupture life of fine grain area at higher than Ac3 temperature is shortest. The phe- nomenon is more obvious with the increase of test temperature.