冷处理对Q345C钢组织及力学性能的影响

Effects of Cold-treatment on Microstructure and Mechanical Properties of Q345C Steel

通过光滑圆棒拉伸试验,研究了不同冷处理温度对锻态Q345C钢组织与力学性能的影响。结果表明,低温处理后Q345C的基体上析出碳化物的数量增多,使其强度得到提高;经过低温处理后,Q345C钢的抗拉强度和断裂强度均有所提高,但断后伸长率和截面收缩率却随冷处理温度降低而减小,并且在-20^-40℃发生较大转折点,出现了韧脆转变。

By tensile test with the smooth round bar, the effects of cold-treatment temperatures on the microstructure and mechanical properties of forged steels-Q345C were studied. The results show that, the number of precipitated carbides in the matrix ofQ345C increases after low temperature treatment, which can make its strength improve. Both ofQ345C steel tensile strength and breaking strength are improved after cold treatment, but the elongation rate and cross-section shrinkage decreases with the temperature of cold treatment decreasing after cold treatment. The larger turning point appears and emerges ductile-brittle transition at -20 ℃ to -40℃.