一种高性能弹簧钢铸态组织含铌析出物研究

Morphologic Characteristics of Niobium-Containing Precipitates in As-Cast Structure of the High Performance Spring Steel

对一种高性能弹簧钢铸态组织中的含铌析出物进行了观察研究。采用光学显微镜及扫描电镜对析出物形貌、尺寸、分布进行观察,并用能谱分析仪对析出物进行成分分析。结果显示,含铌析出物主要以粗大的条状及一些不规则形状存在于铸态组织中,宽度大约1~2μm,长度大约2~40μm;析出物在基体中存在两个明显的聚集区,一个在晶界位置,经分析主要为Nb、V、Ti的碳氮化物;另一个在基体中呈随机分布状态,经Thermo-Calc热力学软件计算及结合扫描电镜分析判断,该区域的析出物可能是Fe2Nb共晶体。

The niobium-containing precipitates in as-cast structures of the high performance spring steel were investigated in present study. The morphology, size and distributions of precipitates were observed by using of optics microscope, scanning electron microscope （TEM）, and the compositions were analyzed by energy dispersive spectrometry （EDS）. The results indicate that the precipitates distribute randomly in as-cast structures as thick strip and irregular sharps. These precipitates are usually in the width of about 1-2 l^m and the length of about 2-40 txm. Besides, there are two accumulation areas in steel matrix for precipitates. One is located at grain boundary, where the precipitates are the mixture of niobium, vanadium and titanium carbonitrides. The other distributes randomly in steel matrix, where the precipitates may be Fe2Nb eutectic in terms of Thermo-Calc thermodynamic calculation and EDS analysis.