Chemical Analysis of Metals in Failure Analysis

2002 ◽  
pp. 429-436
Keyword(s):  
Chemical Analysis ◽  
Failure Analysis

scholarly journals Failure Analysis of fractured Fixing Bolts of a Mobile Elevating Work Platform using Finite Element Methods

2019 ◽  
Author(s):  
DongHoon Choi ◽  
Jae-Hoon Kim
Keyword(s):  
Finite Element ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Failure Analysis ◽  
Visual Inspection ◽  
Standard Procedure ◽  
Fatigue Analysis ◽  
Certification Authority ◽  
Element Analysis ◽  
Safety Certification

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.

Failure Analysis on Heating Surface Tube Crackof High Temperature Reheater in Station Boiler

2013 ◽  
Vol 804 ◽  
pp. 333-336
Author(s):  
Yun Jian Jiang ◽  
Xiang Feng Zheng ◽  
Rong Gang Xue ◽  
Guo Zhen Dong ◽  
Ji Feng Zhao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Electron Microscope ◽  
High Temperature ◽  
Chemical Analysis ◽  
Scanning Electron Microscope ◽  
Failure Analysis ◽  
Heating Surface ◽  
Welding Residual Stress ◽  
Microscope Analysis ◽  
Scanning Electron

Through methods, such as microscope analysis, chemical analysis, metallography examination and scanning electron microscope etc, the causes resulting in high temperature reheater tube cracking of station boiler have been analyzed. The result indicates the crack is reheat crack, and structure stress, higher hardness and excessive welding residual stress are the primary inducement of tube joint crack.

scholarly journals Failure analysis of performance vehicle mechanical gear

2018 ◽  
Vol 188 ◽  
pp. 04019 ◽  
Author(s):  
Antonios D. Tsolakis ◽  
Konstantinos I. Giannakopoulos ◽  
Andreas S. Gkertsos
Keyword(s):  
Chemical Composition ◽  
Chemical Analysis ◽  
Failure Analysis ◽  
Dynamic Loading ◽  
Power Transmission ◽  
Working Environment ◽  
Commercial Vehicles ◽  
Machine Element ◽  
Analysis Of Performance

Gears are the main machine element in vehicle power transmission trains. In commercial vehicles, power transmission trains design complexity consists of the determination of the loading parameters which depends upon the working environment of the performance vehicle. In the present work a gear failure under dynamic loading is investigated. The failed gear is part of a 2 speed gearbox of a Rotax DD2 2-stroke Open- Wheel performance vehicle (go-cart type). The gearbox was in racing conditions when failure occurred. The vehicle was speeding in 2nd Gear at wide open throttle when instantaneously the driver by fault downshifted to 1st gear. The result was for the first gears break a whole piece and eventually the system to go out of operation. Chemical composition of the examined metallic components was determined via EDAX chemical analysis.

Failure Analysis and Welding Repair for Water Wall Connection Tube Burst of SA210C Steel

2014 ◽  
Vol 998-999 ◽  
pp. 422-425 ◽  
Author(s):  
Xiang Feng Zheng ◽  
Nan Wu ◽  
Yun Jian Jiang ◽  
Wen Bin Li ◽  
Xiao Jun Hao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Chemical Analysis ◽  
Failure Analysis ◽  
Heat Input ◽  
Mechanical Analysis ◽  
Raw Material ◽  
Material Defects ◽  
Microscope Analysis ◽  
Water Wall ◽  
Water Wall Tube

Through methods, such as microscope analysis, mechanical analysis, chemical analysis, metallography examination etc, the causes resulting in water wall tube bursting of 300MW station boiler have been analyzed. The raw material defects is the primarily inducement of bursting failure. In welding tube, the measures of reducing residual stress, such as lower welding heat input, reducing thickness of welding layer and so on, were taken. The welding repair succeeded greatly.

Failure Analysis on Tee Joint Crack of Subcritical Power Station Boiler Final Superheater Header

2011 ◽  
Vol 311-313 ◽  
pp. 615-618
Author(s):  
Xiang Feng Zheng ◽  
Yan Ting Feng ◽  
Xiao Guang Niu ◽  
Qing Wang ◽  
Xiao Jun Hao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Chemical Analysis ◽  
Failure Analysis ◽  
Mechanical Analysis ◽  
Welding Residual Stress ◽  
Power Station ◽  
Metallographic Examination ◽  
Microscope Analysis ◽  
Power Station Boiler

Through methods, such as microscope analysis, mechanical analysis, chemical analysis, metallographic examination, the causes resulting in tee joint crack of subcritical power station boiler final superheater header (12Cr1MoV) have been analyzed. The result indicates the tee joint crack is reheat crack, and irrational structure and excessive welding residual stress are the primary inducement of tube joint crack.

scholarly journals ANALISA KEGAGALAN PADA PIPA ULIR DI LINGKUNGAN PERMINYAKAN = FAILURE ANALYSIS OF TUBING-DRILL PIPES UNDER OIL ENVIRONMENT

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Deden Suripto
Keyword(s):  
Chemical Analysis ◽  
Failure Analysis ◽  
Material Selection ◽  
Drill Pipe ◽  
Testing Methods ◽  
Material Test ◽  
Hardness Tests ◽  
Passivation Layers ◽  
Drill Pipes ◽  
Oil Company

The a research on the damage of tubing-drill pipes at an oil company, has been carried out. Failure of the component may be caused by many factors including material selection and their mishandling during in service. The objective of this research was to find out the reason of any failure or defects of a material during in, some testing methods were used, namely: visual and dimensions test, strength and hardness tests, macroscopic and microscopic test, the chemical analysis of material test, and SEM/EDS test. The results of proved that there were some corrosive elements such as the Cl and S-2 so that there was a the potential for the occurence of pitting and crevice corrosivation at the end of screws and these will be penetrated into the passivation layers of Fe2O3 that absorb aggressive anions such as Cl - and S-2.Keywords : failure analysis, drill pipe, corrosionAbstrak Penelitian terhadap kerusakan pada pipa ulir pada lingkungan perminyakan ,telah dilakukan. Kegagalan dari suatu komponen dapat disebabkan oleh berbagai macam faktor, mulai dari kesalahan pemilihan material sampai dengan kesalahan operator dalam service-nya. Tujuan penelitian adalah untuk mencari penyebab kegagalan terjadinya cacat pada material tubing setelah dioperasikan. Untuk mengetahui penyebabnya dilakukan analisa kegagalan dengan menggunakan beberapa metode, yaitu: pemeriksan visual dan dimensi, pengujian tarik dan kekerasan, pemeriksaan makroskopis dan mikroskopis, pengujian komposisi kimia bahan, dan pengujian SEM/EDS. Hasil penelitian membuktikan bahwa adanya unsur korosif dalam material seperti CL- dan S-2 sehingga sangat potensial untuk terjadinya serangan korosi sumuran maupun korosi celah kikisan pada ujung ulir dan akan berpenetrasi pada lapisan pasivasi Fe2O3 yang sifatnya mengabsorbsi anion-anion agresif seperti CL- dan S-2Kata kunci : analisis kegagalan, pipa ulir, korosi.

The Failure Analysis Process

2012 ◽  
pp. 549-583
Keyword(s):  
Chemical Analysis ◽  
Failure Analysis ◽  
Mechanical Testing ◽  
Metallographic Analysis ◽  
Fracture Surfaces ◽  
Service Testing ◽  
Analysis Process

Abstract This chapters discusses the basic steps in the failure analysis process. It covers examination procedures, selection and preservation of fracture surfaces, macro and microfractography, metallographic analysis, mechanical testing, chemical analysis, and simulated service testing.

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