松弛法研究微合金钢碳氮化物的应变诱导析出行为

INVESTIGATION OF STRAIN-INDUCED PRECIPITA TION BEHMIOR IN A MICROALLOYING STEEL BY STRESS RELAXATION METHOD

在Gleeble热模拟机上采用应力松弛方法，研究了一种NbTiV微合金化钢奥氏体应变诱导析出行为，结果表明：实验钢的沉淀析出PTT曲线是典型的“C”曲线形状，沉淀发生具有一个最快析出温度，大致在900－920℃奥氏体预变形加速沉淀析出过程的进行，使PTT曲线向左上方偏移，奥氏体中的沉淀相形貌有球形和方形两种，其中方形沉淀相是均热过程中的未溶质点，以TiN为主，球形沉淀是应变诱导析出相。

The strain induced precipitation of a NbTiV microalloying steel in austenite region was investigated by the stress relaxation method on Gleeble hot simulator. The results show that the shape of precipitation-temperature-time (PTT) is typical C curve, and the fas test precipitation was about 900-920℃. Deformation accelerates the precipitation kinetics and shifts the PTT diagrams leftside and upside. Two kinds of precipitated particles in austenite, cubic and spheric, were observed.The cubic particles are mostly TiN undissolved during reheating, while the spheric particles are strain induced precipitates.