摘要
采用显微硬度测试、扫描电镜(SEM)、透射电镜(TEM)和三维原子探针(3DAP)等测试手段分析了珠光体钢丝在冷拔过程中显微硬度、组织变化及大应变变形后碳原子的分布和浓度变化。结果表明:随着应变量的增加,组织逐渐转向拉拔方向,片层间距减小,最后在纵截面上形成平行于拉拔方向的层片状组织,横截面上呈现为卷曲状的层片组织;3DAP测试显示,渗碳体在变形过程中发生了部分溶解,溶解的碳原子从渗碳体相移动到铁素体相,碳原子在铁素体中形成过饱和;在拉拔过程中铁素体内部位错密度增加、片层间距减小和渗碳体发生分解释放出碳原子对位错运动产生较大阻力,使珠光体钢丝的硬度随着拉拔应变量的增加而增加。
The microstructure evolution,strengthening effects of the pearlite steel wire during heavy cold-drawing and distribution and the concentration change of carbon atoms after severe plastic deformation were investigated by means of hardness test,scanning electron microscopy（SEM）,transmission electron microscopy（TEM） and three-dimensional atom probe（3DAP）.The results show that the microstructure turns to the drawing axis and lamellar spacing decreases during the cold drawing.The lamellar structure parallel to the drawing direction in the longitudinal section and curling structure in the cross section are observed.3DAP testing results show that partial dissolution of cementite can be observed during cold deformation,the dissolution of carbon atoms transferring from cementite to ferrite,which is higher than that of the equilibrium solubility of carbon in ferrite.The hardness of the steel wire increase with increasing drawing strain due to the dislocation density in ferrite increases,lamellar spacing decreases and the dissolution of cementite during the cold drawing.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2016年第6期125-131,共7页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51361004
51461007)
贵州省科学计划(201315
20147001
20142003)
新金属材料国家重点实验室开放基金(2011Z04)
贵州省百层次创新型人才项目(20164014)
关键词
珠光体钢丝
显微组织
渗碳体
三维原子探针
pearlite steel wire
microstructure
cementite
three-dimensional atom probe
