摘要
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。
Anmealing treatment with different holding time and simulated baking tests were carried out for a low carbon steel to examine the infcuence of different heat treatments on bake hardening ability of the steel.The simulated baking process was heat treated at 170 ℃ for 20 min after 2% prestrain.Microstructure and grain size distribution of the steel after the heat treatment were observed,and the bakehardening（ BH） value of the steel was measured and internal friction of the steel under heat treatment state and baking state was tested.The results show that the BH value of the as received steel is lower than that of the steel after heat treatment,and the grain size and uniformity of the grains in the samples increase with the increasing of holding time but the BH value decreases gradually.Compared the results of the internal friction tests for the steel before and after bake treatment,the height of Snoek peak after baking is reduced,but the SKK peak increases.With the increasing of the holding time,the content of interstitial carbon atoms increases and the height of SKK peak decreases,both the two are responsible for the variation of the BH values.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2017年第1期89-93,共5页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51274121)
关键词
低碳钢
热处理
烘烤硬化
晶界
内耗
low carbon steel
heat treatment
bake-hardening
grain boundary
internal friction
