直升机用马氏体钢锻件裂纹产生机理与控制

Mechanism and Control of Cracks in Martensite Steel Forgings for Helicopters

针对直升机用马氏体钢锻件易产生裂纹的问题,分析了酸洗、吹砂、退火对锻件裂纹的影响,探究了锻件裂纹产生机理及规避方法。研究发现,马氏体钢锻件经锻造后直接酸洗,锻件表面经荧光磁粉检测发现明显的表面裂纹,酸洗时间越长,裂纹越长,而锻件经喷砂或退火后再酸洗,锻件表面无裂纹产生。马氏体钢锻件表面裂纹产生的原因主要与锻件表层的残余应力有关,由于锻件表面残余应力较高,酸洗后易产生裂纹,经吹砂或退火后表面残余应力降低、酸洗后无裂纹产生。

Aiming at the problem that the martensite steel forgings for helicopter are prone to crack, the effects of pickling, sand blowing and annealing on the crack of forgings were analyzed, and the mechanism and evading method of forging crack were explored. It is found that when the surface of martensite steel forgings is directly pickled after forging,obvious surface cracks are found by fluorescent magnetic powder detection. The longer the pickling time, the longer the crack is. After sandblasting or annealing and then acid pickling, there are no cracks on the surface of the forgings. The causes of surface cracks in martensite steel forgings are mainly related to the residual stress on the surface of forgings. Because of the high residual stress on the surface, cracks are easy to occur after pickling of forgings. After blowing sand or annealing, the surface residual stress decreases and no cracks occur after pickling.