Abstract: The     second    phase    particles    in     simulated    weld(H08C    weld    wire-0.06C,1.44Mn,0.24Mo,0.04Ti,  0.01V)and     coarse     grained     heat     affected     zone(CGHAZ)of     Ti-V-Nb     microalloyed     steel(0.08C,1.29Mn,0.02Ti, 0.04V,0.04Nb)have  been  studied  by  using  carbon  extraction  replica  technique.Results  showed  that  size  of  most  second phase particles in parent metal was ≤30 nm with average  size  19.70 nm; there was a lot of residual carbo-nitride particles in CGHAZ of which the average size increased to42.78 nm,and the shape of residual particles changed from irregular morphology in parent metal to cubic in CGHAZ in which the Ti content obviously increased; and most of carbo-nitride particles in weld dissolved,the TiO formed in bath combined with other deoxidising and desulphurizing products to form large scale inclusions  and  the  inclusions  and  second particles  containing Nb,V  didn't  find  out  in  weld.

Key words: Ti-V-Nb Microalloying Steel,Second Phase Particles,Weld,CCHAZ

摘要： 利用萃取复型技术研究了Ti-V-Nb微合金钢(%:0.08C、1.29Mn、0.02Ti、0.04V、0.04Nb)模拟粗晶热影响区及焊缝(H08C焊丝%:0.06C、1.44Mn、0.24Mo、0.04Ti、0.01V)第二相粒子。结果表明,母材大部分第二相粒子≤30nm,平均尺寸19.70nm;焊接粗晶区仍残留较多的碳氮化合物粒子,粒子平均尺寸增大至42.78nm,粒子由母材中不规则形状变为方形,粒子Ti含量显著提高。焊缝中绝大部分碳氮化合物粒子发生溶解,熔池中生成的TiO与熔池中其他脱氧和脱硫产物结合成尺寸较大的夹杂物,在焊缝中未发现含Nb、V的夹杂物和第二相粒子。

关键词: Ti-V-Nb微合金钢, 第二相粒子, 焊缝, 粗晶热影响区