Analysis on Welding Crack of Subcritical Power Station Boiler Platen Superheater Header

2012 ◽  
Vol 251 ◽  
pp. 446-449 ◽  
Author(s):  
Yan Ting Feng ◽  
Xiang Feng Zheng ◽  
Xue Xia Xu ◽  
Guo Zhen Dong ◽  
Yong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welding Residual Stress ◽  
Composition Analysis ◽  
Power Station ◽  
Element Analysis ◽  
Test Chemical ◽  
Welding Defects ◽  
Chemical Composition Analysis ◽  
Leakage Failure ◽  
Power Station Boiler

Welding crack analysis was carried out on tee joint crack of boiler platen superheater header (12Cr1MoV) of subcritical power station applying finite element analysis,microanalysis, mechanical properties test, chemical composition analysis, metallography examination and SEM observation etc. Results indicated that the improper structure, the original welding defects, higher welding heat input, excessive welding residual stress and improper heat treatment led to cold crack and reheat crack ,then induced to the leakage failure while operating.the welding crack originated at the original defects, connected with reheat cracks during propagation and led to leakage finally.

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

2012 ◽  
Vol 538-541 ◽  
pp. 1992-1997
Author(s):  
Yan Ting Feng ◽  
Xiang Feng Zheng ◽  
Xue Xia Xu
Keyword(s):  
Mechanical Properties ◽  
Welding Residual Stress ◽  
Composition Analysis ◽  
Power Station ◽  
Cause Analysis ◽  
Test Chemical ◽  
Welding Defects ◽  
Chemical Composition Analysis ◽  
Leakage Failure ◽  
Power Station Boiler

Failure cause analysis was carried out on tee joint crack of boiler platen superheater header (12Cr1MoV) of subcritical power station applying microanalysis, mechanical properties test, chemical composition analysis, metallography examination and SEM observation etc. Results indicated that the tee joint crack originated at the original defects, connected with reheat cracks during propagation and led to leakage finally. The improper structure, the original welding defects, overhigh welding heat input, and excessive welding residual stress resulted in the leakage failure.

Fracture Failure Analysis of N80 Q Marine Casing

2013 ◽  
Vol 318 ◽  
pp. 331-335
Author(s):  
Hong Zhang ◽  
Quan Luo ◽  
Xu Hui Liu ◽  
Peng Wang ◽  
Ding Feng
Keyword(s):  
Mechanical Properties ◽  
Fracture Analysis ◽  
Metallographic Analysis ◽  
Composition Analysis ◽  
Service Environment ◽  
Fracture Failure ◽  
Completion Process ◽  
Casing Pipe ◽  
Chemical Composition Analysis ◽  
Mechanical Properties Testing

The 13-3/8〞casing of a well was bent down and broken off in the marine development completion process. The cause for the fracture is systematically analyzed by means of chemical composition analysis, mechanical properties testing, macro and micro fracture analysis and metallographic analysis. The results indicate that, the heterogeneity of the casing material and large oxide metallurgical inclusions found in fracture place severely reduce the properties of the material, which lead to the failure of casing pipe in bad service environment.

Failure Analysis of Hot Clamp Induced Cracking on Hydrogen Reformer Outlet Pigtail Tubes

2019 ◽  
Vol 795 ◽  
pp. 340-345
Author(s):  
Luo Wei Cao ◽  
Guo Shan Xie ◽  
Min Zhen Zhao
Keyword(s):  
Mechanical Properties ◽  
Failure Analysis ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Composition Analysis ◽  
Impurity Atoms ◽  
Chemical Composition Analysis ◽  
Mechanical Properties Testing ◽  
Metallurgical Evaluation ◽  
Reformer Tube

Failure analysis of the hot clamped outlet pigtail tubes connected with hydrogen reformer tube in refineries has been carried out. In this paper, hot clamp induced cracking on Incoloy 800HT outlet pigtail tube of a reformer unit is studied by microscopic observation and mechanical properties testing. Metallurgical evaluation and chemical composition analysis have been performed on both hot clamped cracking tube and no cracking one. Results indicated that the most important parameter affecting the high temperature brittleness of pigtails are the Ni/Cr value, surface grain size and impurity atoms grain boundary segregation.

scholarly journals Separation of Cenospheres from Fly Ashes by Floatation Method

2010 ◽  
Vol 13 (1-2) ◽  
pp. 89 ◽  
Author(s):  
L.M. Manоcha ◽  
K.A. Ram ◽  
S.M. Manocha
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Thermal Power ◽  
Ceramic Particle ◽  
Composition Analysis ◽  
High Concentration ◽  
Fly Ashes ◽  
Power Station ◽  
Different Types ◽  
Chemical Composition Analysis

Fly-ashes are non-combustible mineral residues which are produced from coal in thermal power plants. Four different types of fly ashes were collected from different power station in Gujarat. Characterization through SEM shows that fly ash contains cenosphere i.e. gas bubble containing ceramic particle independent of their bulk density. Floatation technique was used for the separation of cenosphere from fly ash. Two solvents with extremely different densities were used for the separation of cenospheres. All methods gave approximately yield of less than 1 % cenosphere in fly ash. Color of cenospheres varied from gray to almost white and the value of density range from 0.4 – 0.8 g/cc. Further, chemical composition analysis revealed that cenospheres do not contain any high concentration of hazardous elements.

scholarly journals Analysis and Research on the Cause of Wind Turbine Blade Bolt Fracture

2021 ◽  
Vol 2133 (1) ◽  
pp. 012028
Author(s):  
Feng Yun ◽  
Jun Liu ◽  
Chunyu Liu ◽  
Xiaochun Zhao
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Stress Concentration ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Farm ◽  
Composition Analysis ◽  
Chemical Composition Analysis ◽  
Mechanical Properties Testing ◽  
Load Impact

Abstract In 2019, inspection personnel of a wind farm went to the tower and found that a total of 6 bolts of blades in the hub of a wind turbine had broken and failed. In order to find out the cause of fracture, the fracture bolt was comprehensively detected and analyzed by means of appearance morphology analysis, chemical composition analysis, mechanical properties testing, microstructure testing and fracture micro-area analysis. The results show that the main reasons for the bolt fracture are as follows: under the action of the bolt’s constantly changing and repeated wind load impact and the alternating load caused by blade rotation during the operation of the fan, the crack source is formed along the bottom of the thread with serious stress concentration and expands in fatigue mode until the whole fracture fails.

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.

Microstructure and Mechanism of Concrete Using Inorganic Silicate Admixture

2013 ◽  
Vol 284-287 ◽  
pp. 1235-1241
Author(s):  
Si Yu Zou ◽  
Ran Huang ◽  
An Cheng ◽  
Wei Ting Lin ◽  
Jia Liang Chang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Porous Structure ◽  
Cement Hydration ◽  
Microscopic Analysis ◽  
Positive Influence ◽  
Composition Analysis ◽  
Hydration Products ◽  
Chemical Composition Analysis ◽  
Porosity Measurements

The study evaluates the properties of concrete mixed with inorganic silicate admixture. The admixture was used in proportions of 3%, 5%, and 7% of the weight of the cement. We performed tests on compressive strength and elastic modulus to evaluate the mechanical properties of concrete. Results show that the addition of the inorganic silicate admixture has a positive influence on the mechanical properties of concrete, with the best results obtained with 3% admixture. MIP porosity measurements determined that the addition of inorganic silicate admixture increased the density of the porous structure. SEM microscopic analysis revealed many needle-like protrusions into the porous structure of concrete. XRF chemical composition analysis indicated that these structures comprised mainly Na2O and SiO2. Can with cement hydration products Ca(OH)2 bring in Chemical reaction. Inferred pore structure Within be C-S-H gel of needle-like protruding structure. it can improve the main cause of mechanical properties of concrete.

scholarly journals PENGARUH JACKETING PADA KELAYAKAN OPERASIONIL PROSES COLUMN DISTILASI = THE INFLUENCE OF JACKETING ON PROFICIENCY OF DESTILATION COULUMN PROCES

2016 ◽  
Vol 10 (1) ◽  
pp. 27-34
Author(s):  
M. N. Setia Nusa
Keyword(s):  
Chemical Composition ◽  
Hardness Test ◽  
Composition Analysis ◽  
Research Results ◽  
Test Chemical ◽  
The Future ◽  
Chemical Composition Analysis ◽  
The Impact

Abstract A column distillation has been operated for 42 years , Leaking often happens in top of tray part. it has been repaired by jacketing and patching. Meantime there are still some leaks and damages happens in top tray. Some research and repair action were conducted to avoid the same problem in the future and to know the recent condition of the column using fractography examination, Metallography examination, hardness test, chemical composition analysis, thickness and pundit and the result will be deriving us to the caused of the failure and to the impact of the used of patching and jacketing on material. The research results reveal any corrosion and the elements that have been uneven jacketing conditions only at the top of the destilation column. AbstrakColumn distilasi telah beroperasi selama 42 tahun, beberapa kali mengalami kebocoran di dinding tray bagian atas dan setiap kali repair dilakukan dengan jacketing dan patching. Pada saat ini masih ditemukan ada beberapa kerusakan/kebocoran juga pada tray atas, untuk itu perlu dilakukan penelitian untuk tindakan repair dan mengetahui kondisi terkini column melalui pemeriksaan fraktografi, metalografi, uji kekerasan, komposisi kimia, ketebalan dan pundit sehingga secara keseluruhan hasilnya dapat mengetahui penyebab kerusakan dan mengetahui pengaruh patching dan jacketing pada material. Hasil penelitian ditemukan adanya unsur korosi serta kondisi jacketing yang sudah merata pada bagian atas coulumn destilasi. 

Research on Welding Repair for Tee Joint Crack of Final Superheater Header of 300MW Station Boiler

2012 ◽  
Vol 235 ◽  
pp. 96-100
Author(s):  
Xiao Guang Niu ◽  
Qing Wang ◽  
Xiang Feng Zheng ◽  
Xue Xia Xu ◽  
Hui Fan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Main Crack ◽  
Welding Residual Stress ◽  
Fusion Line ◽  
Power Station ◽  
Metallographic Examination ◽  
Small Cracks ◽  
Steam Pipe ◽  
Power Station Boiler

Through methods, such as microscope analysis, metallographic examination, the crack located nearby the fusion line between tee joint and outlet steam pipe of subcritical power station boiler final superheater header is reheat crack (the main crack occurred in the heat affected zone and extended along the fusion line and grain boundary in HAZ. There are many small cracks paralleling with main crack). The base metal material (12Cr1MoV) and excessive welding residual stress are the primary inducement of crack. In repair crack, the measures of reducing residual stress, such as lower welding heat input, reducing thickness of welding layer, hammer blowing, assigning reasonably heat treatment power ,lengthening holding time and so on, were taken. The welding repair succeeded greatly.

scholarly journals Production of sinters from commercial powder mixtures for a matrix of diamond impregnated tools

Mechanik ◽  
2017 ◽  
Vol 90 (1) ◽  
pp. 54-55
Author(s):  
Joanna Borowiecka-Jamrozek ◽  
Jan Lachowski
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Composition Analysis ◽  
Powder Mixtures ◽  
Chemical Composition Analysis ◽  
Iron Based ◽  
Commercial Iron ◽  
Size Powder ◽  
Scanning Electron

The paper presents the results of analyzing mechanical properties of the sinters obtained from the commercial iron-based powder mixtures. Parameters mechanic, plastic and density, hardness and porosity of the sinters were determined. The sinters microstructure and the chemical composition analysis were carried out by using the scanning electron microscope. The results were compared with the properties of the sinters obtained from the cobalt SMS (submicron size) powder.

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