时效处理对Stellite 6B钴基高温合金组织性能的影响

Effect of aging treatment on microstructure and properties of Stellite 6B cobalt-based superalloy

为了探究时效处理工艺对Stellite 6B钴基高温合金组织性能的影响,采用不同的时效处理方法对合金试样进行了处理,对比分析了不同时效处理工艺下试样的微观组织、显微硬度及碳化物析出情况。结果表明,随着时效处理时间的延长,碳化物的析出量增加,晶界上也开始析出能够强化晶界的碳化物链。时效处理参数为980℃×12h时,效果最佳。此时,组织全部奥氏体化,基体和晶界上无大块的一次碳化物;析出的M23C6碳化物弥散均匀分布,尺寸控制在1μm左右,最大不超过3μm;晶界网状碳化物断开成碳化物链,最长不超过5μm;合金硬度为HRC47.18,能够满足挤压模具对材料硬度的要求。

In order to investigate the effect of aging treatment on the microstructure and properties of Stellite 6 Bcobalt-based superalloy,different aging treatment methods were used to treat the alloy samples.The microstructure,microhardness and carbide precipitation of the samples under different aging treatments were compared and analyzed.The results showed that as the aging treatment time increased,the precipitation of carbides increased,and the carbide chains that strengthen the grain boundaries begin to precipitate on the grain boundaries.When the aging treatment parameter was 980°C×12 h,the effect was the best.At this time,the microstructure was completely austenitized,and there was no bulk primary carbide on the matrix and the grain boundary.The precipitated M23 C6 carbides were uniformly dispersed and their size was controlled at about 1μm,and the maximum was not more than3μm.The crystalline carbides were broken into carbide chains,and the longest was up to 5μm.The alloy hardness was close to HRC47.18,which can meet the hardness requirements of the extrusion die materials.