Ti-V-Nb微合金钢中的第二相粒子及其对焊接热影响区奥氏体晶粒长大的影响  

Effect of Second-phase Particle on Austenite Grain Size in HAZ in Ti-V-Nb Microallyed Steel

作　　者：陈俊华[1] 亓效刚[2] 李华宾[1] 陈茂爱[2] 

机构地区：[1]山东劳动职业技术学院,山东济南250021 [2]山东大学材料液态结构及其遗传性教育部重点实验室,山东济南250061

出　　处：《热加工工艺》2004年第6期13-15,61,共4页Hot Working Technology

摘　　要：利用萃取复型技术及焊接热模拟技术研究了Ti-V-Nb微合金钢及热影响区中的第二相粒子及其对HAZ区奥氏体晶粒长大的影响。研究表明,微合金钢中存在大量弥散分布的细小粒子,这些粒子是Ti、Nb、V等元素的碳氮化合物,具有很高的稳定性。在焊接热循环过程中,这些粒子能够显著地阻止奥氏体晶粒长大。焊接热循环峰值温度在1200℃以下时,热影响区中的第二相粒子在热循环过程中仅发生轻微的溶解及长大,奥氏体晶粒长大程度很小,且奥氏体晶粒尺寸基本不随焊接热输入(t8/5)及热循环峰值温度(Tm)的变化而变化。Tm在1250℃以上时,热影响区中的第二相粒子显著减少而尺寸显著增大,奥氏体晶粒尺寸随t8/5及Tm的增大而显著增大。Particle in Ti-V-Nb microalloyed steel and its effect on the growth of austenite grain in HAZ were investiated by using carbon extraction replica technology and welding thermal simlation.Experiment results and analysis show that large amount of small dispersed particle containing Ti,Nb and V exist in the steel,and those particles are very stable and can effectively inhibit austenite grain coarsening during welding thermal cycle;with the peak temperature of welding thermal cycle not higher than 1200℃,the particle dissolving and coarsening are very weak,thus the austenite grain coarsening rate is very slow,and the austenite grains size does not increase significantly with the increase of t_(8/5);with the the peak temperature of welding thermal cycle higher than 1250℃,the particle in HAZ are evidently dissolved and coarsened,the austenite grain coarsening rate is very slow,and the austenite grains coarsening rate increases,and the grain size increases significantly with the increase of　t_(8/5) and T_m.

关 键 词：微合金钢 奥氏体晶粒尺寸 第二相粒子 

分 类 号：TG142.411[一般工业技术—材料科学与工程]