【摘要】 采用宏观、微观断口、显微组织及力学性能分析手段,对液压油缸开裂的原因进行分析。结果表明,液压油缸的开裂形式为早期疲劳开裂,疲劳源位于油缸表面焊点处,由于焊点的冷却速度过快,局部形成了马氏体。裂纹源处经过反复摩擦形成白亮区,裂纹从焊点白亮区处沿油缸纵向迅速向两侧扩展。由于母材原始组织不均匀,呈现混晶、带状组织,促进了裂纹的快速扩展,最后造成液压油缸开裂。更多还原

【Abstract】 Failured hydrocylinder was analyzed by macro and micro fracture observation,metallographic microstructure analysis and mechanical property test. The results showed that the hydrocylinders cracking form was early fatigue cracks,and the fatigue source was formed at the solder joints because of local rapid cooling and resulting in martensite formed. Bright white area was formed at the crack source due to repeated friction,and the cracks extended quickly in the longitudinal direction from the both sides of solder joints. Moreover,the original inhomogeneous microstructure with mixed grain and banded structure promoted the rapid expansion of cracks,finally lead to the hydrocylinder cracking.更多还原