高碳铬轴承钢超长寿命疲劳破坏过程的研究

FATIGUE FRACTURE PROCESS OF A HIGH-CARBON-CHROMIUM BEARING STEEL IN ULTRA-LONG LIFE REGIME

研究了高碳铬轴承钢超长寿命疲劳的破坏过程.结果表明,在超长寿命区,约在疲劳寿命的5%—10%时疲劳裂纹首先在内部夹杂物处萌生,由于夹杂物周围的球形碳化物开始从基体剥离,在夹杂物周围形成许多不连续的微小裂纹.然后,相邻的微小裂纹相互连接,直到疲劳寿命的90%以上,裂纹开始连续扩展.

Fatigue fracture process of high-carbon-chromium bearing steel was studied in ultralong life regime. The results show that fatigue crack began to initiate at an interior inclusion at about 5%-10% of fatigue lifetime, and then many micro-cracks formed dispersively due to the decohesion of spherical carbide around the inclusion from the matrix, which will grow and coalesce each other with fatigue processing. When fatigue lifetime is over 90%, fatigue crack formed from those micro-cracks starts continuous propagation.