Analysis of Corrosion Fatigue-Induced Failure in Concrete Pump Truck Booms

During the operation of a certain type of concrete pump truck, the upper surface of the first-level boom (made from 20MnTiB steel plate) fractures, resulting in significant economic losses.To determine the cause of the fracture, physical and chemical tests including fracture surface morphology, comp...

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Bibliographic Details
Main Author: ZHAO Jun, REN Hongwa, WU Lihui
Format: Article
Language:zho
Published: Editorial Department of Materials Protection 2025-02-01
Series:Cailiao Baohu
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Online Access:http://www.mat-pro.com/fileup/1001-1560/PDF/20250218.pdf
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Summary:During the operation of a certain type of concrete pump truck, the upper surface of the first-level boom (made from 20MnTiB steel plate) fractures, resulting in significant economic losses.To determine the cause of the fracture, physical and chemical tests including fracture surface morphology, composition, mechanical properties, metallography, and scanning electron microscopy were conducted on the fractured boom collected from the site.The test results showed that the fracture originated from a localized pitting corrosion on the inner surface of the boom, which then propagated under the influence of corrosive media and cyclic stress, leading to corrosion fatigue crack growth.The metallographic structure of the main fracture source was similar to that of the welded joint.Comprehensive analysis of the test results confirmed that the primary failure mode of the boom fracture was corrosion fatigue failure; the secondary failure mode was the corrosion fatigue fracture caused by the pitting corrosion pits on the inner wall of the boom steel plate under the action of water vapor that was rich in concrete components and the periodic bending endured by the boom; the tertiary failure mode was attributed to the welder’s arc-striking operation on the steel plate during the welding of the boom box, which damaged the steel plate surface, leading to a layered structure similar to that of a weld joint.The earliest pitting corrosion pit was located on the coarse martensite layer on the surface of the damaged steel plate.
ISSN:1001-1560