某发动机增压器涡轮轴早期疲劳断裂失效分析

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中图分类号：U446.135+2 文献标志码：B DOI：10.19710/J.cnki.1003-8817.20250247

Failure Analysis of Fatigue Fracture in an Engine Turbocharger TurbineShaft

Sun Xiaofen， Gao Yong， Feng Jijun （MaterialandTechnologyResearch Institute，TechnicalCenterofDongfengCommercialVehicleCo.，Ltd.，Wuhan430056）

Abstract：Toaddressthe issue of excessive engineexhaust smokeand insufficient power occurring after275km ofoperation inacertainengine turbocharger，asystematicanalysisof the failed turbine shaft is conductedusing methodssuch as macroscopic inspection，scanning electron microscopy analysis，metallographic observation，and hardness testing.Theresultsindicatethattheturbineshaft fractureisalow-stress，high-cycle fatigue failureunder significant stressconcentration.The fracture originated fromaseverelyscratchedareaatthe filetcaused bypoor grindingprocessing.Therootcauseisidentifiedaspoor lubrication leading todryfriction between theshaftand bearing，subjecting the bearing toabnormal alternating stress.The studyconcludes that although themachining defect createda stressconcentration source，theabnormal operatingcondition （dry friction causedbyoil shortage）is the primary factor triggeringthispremature fracture.

Keywords：Turbocharger，Turbine shaft，Failureanalysis，Stress concentration，Lubricationdeficiency

1前言

涡轮增压器作为提高内燃机效率的关键部件，通过利用发动机排气能量驱动涡轮，进而压缩进气，显著提高发动机的功率输出和燃油经济性[-2]。（剩余4394字）