Investigation of causes of XCMG QY25К lorry-mounted crane accident

The article conducted a study of the causes of the accident of the XCMG QY25K lorry-mounted crane. Visual inspection of the emergency boom (boom in a critical condition) was carried out with the analysis of the state of the material in the broken section. The microstructure of steel in the crack zone was investigated. Chemical analysis of steel with a determination of the mass fraction of chemical elements was performed. Studies of the strength and hardness of material samples were carried out. Theoretically, the maximum tensile and compressive stresses in the section of the failed boom are determined. Comprehensive analysis of the obtained theoretical and experimental research results made it possible to establish the true cause of the accident of the lorry-mounted crane.