Fracture failure analysis of baseplates in a fluidic amplifier made of WC-11Co cemented carbide
Journal Title: Frattura ed Integrità Strutturale - Year 2014, Vol 8, Issue 27
Abstract
A fluidic amplifier is a crucial automatic control component in a liquid jet hammer used to drill hard formations in the oil industry. This study aims to determine the true causes of the fracture failure of baseplates in a fluidic amplifier made of WC-11Co cemented carbide in a very short period of time. Computational fluid dynamics (CFD), theoretical estimation, and finite element analysis (FEA) were employed to analyze the effect of static and dynamic loads on the strength of the baseplates. Fractographic, metallographic, and processing defect analyses were also carried out. The FEA results showed that the static and dynamic loads caused stress concentrations at the actual fracture locations, and the effect of working loads on material strength was allowable and safe. Fracture surfaces exhibited typical characteristics of a brittle fracture. The metallographic analysis revealed that a specific amount of brittle eta-phase (η-phase) was present in the material. The microstructure of the processing cutting zone was inspected and the results revealed that some voids, pores, and microcracks were formed on the processing surface. The manufacturing and processing defects resulted in low stress fracture failure of the baseplates.
Authors and Affiliations
H. Liu, K. Yin, J. M. Peng, Q. L. Yin
La modellazione microstrutturale di materiali a struttura eterogenea: princìpi ed applicazioni
Molti problemi della Meccanica e Fisica dei Solidi e della Scienza dei Materiali, non sono facilmente risolvibili con gli approcci tradizionali. Oltre allo studio delle proprietà effettive dei solidi eterogenei, vi è la...
High temperature fatigue tests and crack growth in 40CrMoV13.9 notched components
The present paper addresses experimentally the high temperature fatigue of 40CrMoV13.9 steel and the effect of surface roughness on fatigue strength and crack initiation. The 40CrMoV13.9 steel is widely used in d...
Fatigue crack growth under remote and local compression – a state-of-the-art review
There is an ever increasing need for accurate understanding of the fatigue crack growth behaviour in major engineering materials and components. With the move towards more complex, probabilistic assessments, the...
Influence of temperature and exploitation period on fatigue crack growth parameters in different regions of welded joints
The influence of exploitation period and temperature on the fatigue crack growth parameters in different regions of a welded joint is analysed for new and exploited low-alloyed Cr-Mo steel A-387 Gr. B. The pa...
Crack front segmentation under combined mode I- and mode III- loading
This article approaches the topic of crack initiation and crack growth behaviour under combined mode I- and mode III-loading conditions. Such loading combinations especially lead to a crack, which unscrew out...