Abstract: 280 connecting rod is one of the most important parts for 16V280ZJ diesel locomo- tive, so it needs much better mechanical performance. However, the crack is often generated at the middle section of connecting rod body on heat treatment process. A temperature-phase transformation-stress coupled 3D non-linear mathematical model has been developed to analyze the reasons of cracking. The simulation and experimen- tal results show that the compressive stress on the cracking position is close to the fracture stress of connecting rod and the reasons of crack are mainly contributed to the carbon content excess of original material or the aging of quenchant.

Key words: crack, phase transformation, non-linear