摘要
焊接热循环中合金元素的偏聚行为决定了热影响区粗晶区(CGHAZ)组织的演变。采用原子探针层析成像技术测定了高强耐火钢在模拟焊接热循环后基体和晶界的合金元素浓度。定量分析了C、Mn、Cr、Mo、Nb、V、Ti等元素在原奥氏体晶界附近的浓度。根据富集因子计算结果,得出元素偏聚程度大小顺序为C>Ti>Mo>V>Nb>Mn>Cr,且Mn和Cr在晶界处存在共偏聚现象。950℃时,晶界偏聚能为111.22 kJ/mol。合金元素在晶界偏聚降低了奥氏体的分解温度,抑制了晶界迁移。
Segregation behavior of alloy elements during welding thermal cycles determines the microstructural evolution in the coarse grain heat-affected zone(CGHAZ).Atom probe tomography was preformed to measure the concentration of alloy elements in matrix and at grain boundaries of high-strength fire-resistant steel after simulated welding thermal cycle.The segregations of C,Mn,Cr,Mo,Nb,V and Ti at the prior austenite grain boundary(PAGB)were quantified.Based on the calculation results of enrichment factor,the order of segregation degree of elements was C>Ti>Mo>V>Nb>Mn>Cr,and it was found that Mn co-segregated with Cr at grain boundary.The grain boundary segregation energy was calculated to be 111.22 kJ/mol in total at 950°C,which was expected to reduce austenite decomposition temperature and inhibit the migration of grain boundary.
作者
陈林恒
桑晨
童志
范益
王红鸿
CHEN Linheng;SANG Chen;TONG Zhi;FAN Yi;WANG Honghong(Nanjing Iron and Steel Co., Ltd., Nanjing Jiangsu 210035, China;Hubei Collaborative Innovation Center for Advanced Steels, Wuhan University of Science and Technology, Wuhan Hubei 430081, China)
出处
《上海金属》
CAS
2021年第2期27-32,共6页
Shanghai Metals
基金
国家自然科学基金(No.51971165)。
关键词
元素偏聚
焊接热循环
原子探针
element segregation
welding thermal cycle
atomic probe
