带弹簧片高压转子连接螺栓组件焊接裂纹故障分析与改进验证

带弹簧片高压转子连接螺栓组件由D头螺栓和弹簧片激光熔焊组成，其因结构简单、设计精巧等原因，在中外各型发动机上广泛使用。为彻底解决各型发动机带弹簧片高压转子连接螺栓组件焊接裂纹故障问题，以某型发动机故障件为基础，通过断口宏微分析、金相检查、焊接深度测量、温度场评估、材料选用分析、结构尺寸分析、有限元仿真计算、分解/装配过程分析等方法，对带弹簧片高压转子连接螺栓组件焊接裂纹故障进行全面的研究，最终定位了故障的根本原因：螺栓组件焊接深度不足且存在明显的焊接薄弱处；螺栓组件弹簧片结构设计不合理，导致自锁螺母分解/装配过程中弹簧片承受不合理扭矩，当扭矩过大时，焊接薄弱处因应力超限而过载破坏。从结构设计、制造工艺等方面给出相应的改进措施，改进后的螺栓组件未再出现裂纹故障，证明了故障定位的准确性和改进措施的有效性。

LIU Chao, WU Zheng-hong, Lin Lei, Song Chang-qi, Ma Jian

The high-pressure rotor connecting bolt assembly with spring plate comprises D-head bolt and spring plate laser fusion welding. It was widely used in various engines at home and abroad due to its simple structure and exquisite design. But crack failures frequently occurred in the welds of this bolt assembly. To completely solve the fault problem of welding cracks in the connecting bolt assemblies of the high-pressure rotor with spring sheets of various types of engines, based on the faulty parts of a certain type of engine, through fracture macro-micro analysis, metallographic inspection, welding depth measurement, temperature field evaluation, material selection analysis, Structural dimension analysis, finite element simulation calculation, decomposition/assembly process analysis, etc., conducted a comprehensive study on the welding crack failure of the high-pressure rotor connecting bolt assembly with spring sheets and finally locate the root cause of the loss: the welding depth of the bolt assembly is insufficient and obvious, the weak spot of welding, the unreasonable structural design of the spring leaf of the bolt assembly causes the spring leaf to bear little torque during the disassembly/assembly process of the self-locking nut. When the torque is too large, the weak welding place will be overloaded and damaged due to excessive stress. Corresponding improvement measures are given from the aspects of structural design and the manufacturing process. The improved bolt assembly has no crack failure, which proves the accuracy of fault location and the effectiveness of the improvement measures.