柱塞卡滞原因分析

某柱塞泵工作中发生柱塞卡滞,经显微形貌观察、光谱分析、电子探针面扫描分析和显微硬度分析等,确定柱塞卡滞的根本原因为原材料组织中存在严重的网状共晶碳化物,降低了强度和韧性,增大了柱塞球面表层的脆性,进而导致了球面部位的接触疲劳抗力下降。严重的疲劳磨损与接触疲劳造成了柱塞球面脱层破坏,由此产生的金属碎屑进入柱塞与衬套的配合间隙处,进而限制了柱塞的自由运动。

Causes analysis of plunger sticking

Plunger stick seizing up happened during plunger pump working. Causes of the seizure was examined by means of microstructure analysis,EDS,SEM,electron probe scanning analysis and hardness test. The analysis results show that the root cause of the plunger seizure is the severe reticulation eutectic carbide existing in the raw material of Cr12 MoV. The internal strength and toughness of the plunger are reduced by these network of eutectic carbides. The contact fatigue resistance is lowered by the larger brittleness of the plunger spherical surface. Plunger seizure is caused by the metal scraping pulled off from the plunger spherical surface which is between the plunger and the sleeve.