均热温度对抗震钢筋奥氏体化及铌固溶的影响

摘要：通过热处理试验结合物理化学相分析实验，对含铌与不含铌的2种试验钢在不同均热温度下的奥氏体晶粒长大情况及含铌钢中铌的固溶规律进行研究。结果表明，均热温度低于1200℃时，含铌钢奥氏体晶粒尺寸均小于无铌钢奥氏体晶粒尺寸；随着均热温度的升高，含铌钢奥氏体中固溶的Nb逐渐增多；均热温度升至1200℃时，含铌钢奥氏体晶粒较无铌钢无明显细化。通过相分析试验研究实际Nb的固溶量与均热温度的关系，发现实际测量得到Nb未溶量随均热温度的升高而减小，对比Nb在奥氏体中的实际固溶与理论固溶的关系，寻找适合的含铌试验钢的理论模型。

Effect of soaking temperature on austenitization and solid solution of niobium in anti seismic rebar

Austenite grain growth in Nb microalloyed/free steels and the solid solution of Nb in Nb microalloyed steel were investigated by heat treatment at different soaking temperatures and physicochemical phase analysis. The results show that austenite grain size of Nb microalloyed steel is finer than that of the Nb free steel when soaking temperature is below 1200℃. The amount of solid solution Nb increases gradually with increase in soaking temperature. With soaking temperature rising to 1200℃, the austenite grain size in the Nb microalloyed steel is not finer than that of the Nb free steel significantly. According to the relationship between undissolved amount of niobium and soaking temperature by phase analysis, the actual total solid solution temperature of niobium in austenite is higher than the theoretical total solid solution temperature. The relationship between the solid solution Nb and the soaking temperature was studied by phase analysis experiments. It was found that the actual measured amount of Nb undissolved decreased with the increase in the soaking temperature. The actual solid solution Nb in austenite was compared with the theoretical value, trying to establish a suitable theoretical model for the Nb microalloyed steel.