退火时间对0.4C-1.0Cr-0.2Mo钢冷轧后组织与性能的影响

Effect of annealing time on microstructure and properties of 0.4C-1.0Cr-0.2Mo steel after cold rolling

利用扫描电镜和电子万能拉伸实验机研究了0.4C-1.0Cr-0.2Mo钢冷轧后退火过程中的组织与性能演变规律。结果表明,冷轧态试验钢中的渗碳体有少量呈球状,在后续的退火过程中球化比例增加,并随退火时间的增加逐渐发生粗化。当退火时间从15 min增加到240 min时,铁素体晶粒尺寸由0.670μm增加到0.803μm,屈服强度由1301 MPa下降至921 MPa,均匀延伸率在退火120 min时达到最大。从整体上看,当冷轧试验钢在600℃退火120 min时,强塑积值达到最高,为5688 MPa·%。

Effect of annealing time on microstructure and property of a medium carbon Cr-Mo steel was investigated by means of scanning electron microscope and electronic universal tensile test machine.The results show that the cementite in the cold-rolled test steel has been spheroidized to some extent,and the spheroidization ratio increases during the subsequent annealing process,and coarsening of the spheroidized carbideds gradually occurs with the increase of annealing time.With the annealing time increased from 15 min to 240 min,the ferrite grain size increases from 0.670 μm to 0.803 μm,the yield strength decreases from 1301 MPa to 921 MPa,and the uniform elongation reaches the maximum when annealed at 120 min.In a word,the product of strength and elongation of the cold rolled steel reaches the highest value of 5688 MPa·% when annealed at 600 ℃ for 120 min.