【摘要】 利用光镜、电镜及冲击试验等研究了Ti V Nb微合金管线钢模拟粗晶区的组织及性能 ,结果表明 ,该钢中存在大量能够阻止原始奥氏体晶粒长大的第二相粒子。t8 5(80 0～ 5 0 0℃冷却时间 )从 1 0s增大到70s,模拟热影响区原始奥氏体晶粒尺寸长大并不严重 ,韧性均较高 ,二次组织均以低碳粒状贝氏体为主。更多还原

【Abstract】 The microstructure and toughness of simulated welding coarse\|grain heat affected zone (CGHAZ) in Ti\|V\|Nb microalloy steels were investigated by optical microscope, transmission electron microscope and impact toughness examination. The results show that there exists a large amount of second phases particles to prevent original austenite grain growth. With the cooling time from 800 ℃ to 500 ℃ (t\- 8/5 ) increasing from 10s to 70s, the coarsening of original austenite grain in CGHAZ is not great, of which the toughness is excellent, and the main second structure at ambient temperature is granular bainite.更多还原