Analysis and Prevention Measures of Pitman Shaft Thread Delayed Fracture
The heat treatmeat process,hardness,applied force and fractographic appearances of the steering gear pitman shaft were analyzed.The crack is considered to be delayed fracture induced by hydrogen.The main factors that influenc the fracture is higher hardness,hydrogen content and stress concentration on the fracture region.In the meantime,the two kinds of processes that reduce hardness on thread:induction tempering and localized anti-carburization are analyzed.It is concluded that induction tempering is an effective way to avoid delayed fracture on pitman shaft thread.