离心式空压机叶轮轮盘开裂原因

Reasons for cracking of impeller discs in centrifugal air compressors

某离心式空压机叶轮轮盘发生开裂并有残块脱落,采用宏观观察、化学成分分析、扫描电镜及能谱分析、金相检验、硬度测试等方法对轮盘开裂的原因进行分析。结果表明:轮盘与叶片圆角表面的冲蚀坑为裂纹源,在离心力和S^(-)、Cl^(-)腐蚀性阴离子的共同作用下,轮盘发生沿晶型应力腐蚀开裂现象;材料中存在粗大的过热组织,且其强度和硬度较大,促进了轮盘发生应力腐蚀开裂。

A centrifugal air compressor impeller disc cracked and had debris falling off.The causes of the disc cracking were analyzed using methods such as macroscopic observation,chemical composition analysis,scanning electron microscopy observation and energy spectrum analysis,metallographic examination,and hardness testing.The results show that the erosion pits on the rounded surface of the wheel disc and blade were the source of cracks,and under the combined action of centrifugal force and S^(-),Cl^(-)corrosive anions,the wheel disc underwent intergranular stress corrosion cracking.There was a coarse overheated structure in the material,and its strength and hardness were relatively high,which promoted stress corrosion cracking of the wheel disc.