论文部分内容阅读
针对低碳钢分别进行了热处理和模拟烘烤,热处理工艺为850℃保温2 min、15 min和30 min后水冷,模拟烘烤工艺为2%预变形后加热到170℃保温20 min。观察了其热处理后的显微组织和晶粒尺寸分布,测试了烘烤硬化(BH)值,分析了热处理态和烘烤态的内耗。研究结果表明,与原始样品相比,热处理样品的BH值较高;随着保温时间延长,平均晶粒尺寸不断增大,晶粒的不均匀性逐渐增加,烘烤硬化值逐渐减小;烘烤前后相比较,Snoek峰高降低,SKK峰高升高;随着保温时间延长,间隙碳原子含量下降,SKK峰逐渐升高,间隙碳原子和Cottrell气团共同影响了BH值的变化。
Heat treatment and simulated baking were respectively carried out for mild steel. The heat treatment process was 850 ℃ for 2 min, 15 min and 30 min for water cooling. The simulated baking process was 2% pre-deformation and then heated to 170 ℃ for 20 min. The microstructure and grain size distribution after heat treatment were observed. The value of bake hardening (BH) was tested. The internal friction of heat treatment and bake state was analyzed. The results show that, compared with the original sample, the BH value of the heat-treated sample is higher; with the holding time prolonging, the average grain size increases, the grain heterogeneity gradually increases, the bake hardening value decreases gradually; Compared with before and after roasting, the peak height of Snoek decreased and the peak height of SKK increased. With the prolongation of holding time, the content of interstitial carbon decreased while the peak of SKK increased gradually. The interstitial carbon atoms and Cottrell air mass together affected the change of BH value.