退火工艺对0.025C-0.326Mn钢组织、织构和力学性能的影响

 为了优化低合金钢的强度和深冲性能,采用连续退火和盐浴退火+过时效工艺,研究了退火温度和过时效温度对0.025C-0.326Mn钢显微组织、织构演变和力学性能的影响。研究结果表明,提高退火温度有利于α纤维织构向γ纤维织构转变;弥散分布的细小碳化物颗粒阻碍晶粒转动,导致在820 ℃退火后的{113}<110>取向晶粒增强,影响{111}面织构的遗传演变过程;过时效工艺有利于高温退火固溶于铁素体中的碳元素析出,进而净化铁素体;过时效温度的增加改善材料伸长率,其中最佳伸长率为36.9%。连续退火试样最佳r值为1.26,而盐浴退火+过时效处理工艺最佳r值为1.39,并且后者抗拉强度满足500 MPa级的要求。

Effect of annealing process on microstructure texture and mechanical properties of 0.025C-0.326Mn steel

In order to optimize the strength and deep drawability of low alloy steel,continuous annealing and salt bath annealing+over-aging process were adopted in this experiment. The effects of annealing temperature and over-aging temperature on microstructure,texture evolution and mechanical properties of 0.025C-0.326Mn steel were investigated. The results show that the increase of annealing temperature promotes the transformation of α texture to γ texture. The dispersed distribution of fine carbide particles hinders grain rotation,resulting in the re-emergence and increase of {113}<110> oriented grains,affecting the genetic evolution of {111} surface texture. The over-aging process promotes the precipitation of solid solution carbon in the ferrite after annealing,and purifies the ferrite. The increase in over-aging temperature improves the elongation of the material,wherein the elongation is preferably up to 36.9%. The r value of the continuous annealing sample is preferably 1.26,however,the salt bath annealing and over-aging process increases the r value to 1.39,and the latter tensile strength meets the requirements of 500 MPa grade.