镍基高温合金中的初生碳化物及其强化作用

Primary carbide and its strengthening roles in K465 and K492 Superalloy

摘要:

对K465和K492合金进行室温拉伸、高周疲劳和差热分析实验，采用扫描电镜和透射电镜，观察和分析铸态下K465和K492合金中初生碳化物的形态、类型及分布，研究铸态K465和K492合金组织中初生碳化物对合金强度的影响。结果表明，在K465合金中形成MC型初生碳化物，呈骨架状，对合金室温强度有利；在K492合金中形成MC型初生碳化物，呈弥散颗粒状分布。当这种初生碳化物颗粒尺寸较大时，降低合金的高周疲劳强度；当这种初生碳化物颗粒尺寸较小时，提高合金的高周疲劳强度。

Abstract:

The tensile, high cycles fatigue and DSC tests were made on K465 and K492 alloy. The morphology and distribution of primary carbide were investigated being used on SEM and TEM. MC-type carbide was formed as Chinese script morphology in K465 alloy. The tensile strength of as–cast K465 alloy was improved at room-temperature because of Chinese script MC-type carbide. Dispersed MC carbide was produced in as-cast K492 alloy. High-cycle fatigue strength was decreased when the size of carbide became large. High-cycle fatigue strength was increased when the size of carbide became small.