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 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.

Analysis of Abnormal Fracture Occurring during Full Scale Tension Increasing to Failure Test of High Strength Low Alloy Steel Casing

2014 ◽  
Vol 788 ◽  
pp. 390-395
Author(s):  
Qi Lou ◽  
Si Rong Yu ◽  
Wei Du ◽  
Hong Chao Chu
Keyword(s):  
Mechanical Properties ◽  
Alloy Steel ◽  
Wall Thickness ◽  
High Strength ◽  
Full Scale ◽  
Metallographic Analysis ◽  
Composition Analysis ◽  
Low Alloy Steel ◽  
Spiral Fracture ◽  
Mechanical Properties Testing

The full scale evaluation test of a set of API Q125 high strength low alloy steel casing specimens was conducted. With the tension increasing to failure, the abnormal fracture occurred on each specimen. A series of testing and analysis including fracture observation, chemical composition analysis, mechanical properties testing, metallographic analysis and SEM analysis were made for the specimen with abnormal spiral fracture. The geometry measurement, visual examination, mechanical properties testing and metallographic analysis were conducted for a new specimen. The mechanical properties of the two specimens are in compliance with the specified material specification. The new specimen has lower external diameter ovality and higher wall thickness eccentricity. The smaller wall thickness is distributed in a spiral shape, similar with the abnormal fracture. The fracture originated in the middle of casing wall, and the fracture position had obvious necking. According to fractography and fracture mechanics analysis, the abnormal spiral fracture was attributed to the metallurgical and geometry imperfection grown out of tubing processing process.

scholarly journals Fracture analysis for lubricating oil pipe of compressor

2021 ◽  
Vol 236 ◽  
pp. 01050
Author(s):  
Jun SI ◽  
Huating LV ◽  
Facai REN
Keyword(s):  
Chemical Composition ◽  
Fatigue Fracture ◽  
Fracture Analysis ◽  
Lubricating Oil ◽  
Metallographic Analysis ◽  
Composition Analysis ◽  
Chemical Composition Analysis

The rupture analysis of lubricating oil pipe has been conducted through chemical composition analysis, metallographic analysis and fracture analysis. The analysis results show that there are machining defects and bidirectional vibration at the joint of lubricating oil pipe, which leads to fatigue fracture.

Fracture Failure Analysis of 127mmG105 Drill Pipe

2012 ◽  
Vol 184-185 ◽  
pp. 248-251
Author(s):  
Fang Po Li ◽  
Shu Mao Zhang ◽  
Yong Gang Liu ◽  
Xin Xu
Keyword(s):  
Mechanical Properties ◽  
Failure Analysis ◽  
Drill Pipe ◽  
Fracture Analysis ◽  
Drilling Process ◽  
Fracture Failure ◽  
Drilling String ◽  
Mechanical Properties Testing

The failure cause of one Φ127mm G105 drill pipe was investigated through mechanical properties testing, optical morphologies and fracture analysis. The results show that drill pipe’s failure reason is the "martensite" white bright layer in its out-surface caused by intense friction in drilling process. Under the effect of torque and tensile loads, lots of cracks initiated in the white bright layer and developed along the vertical. In the end, when its tensile capacity was less than the weight of drilling string, drill pipe fractured along the horizontal. In addition, H2S in the travelling environment promoted crack’s initiation and development.

scholarly journals Failure analysis for tube bundle of methanol condensation recovery heat exchanger

2021 ◽  
Vol 267 ◽  
pp. 02033
Author(s):  
Jiang Chengjun ◽  
Wang Wei ◽  
Xue xiaolong ◽  
Fan gaoping ◽  
Wang Xin
Keyword(s):  
Heat Exchanger ◽  
Tube Bundle ◽  
Hardness Test ◽  
Fracture Analysis ◽  
Metallographic Analysis ◽  
Composition Analysis ◽  
Exhaust Gas ◽  
Shell Side ◽  
Chemical Company ◽  
Chemical Composition Analysis

The S30408 tube bundle of methanol condensation recovery heat exchanger in a chemical company was found leaked during use. The cause of tube bundle leakage was analyzed by means of macroscopic inspection, chemical composition analysis, metallographic analysis, hardness test and leakage fracture analysis. The results show that formic acid and chloride condensate are formed by the exhaust gas in the shell side near the outlet of the shell side, which results in the spot corrosion and stress corrosion cracking of the tubes. Surface coating or replaced material is recommended to prevent such failure.

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.

The Analysis on Causes of Rupture for a Sucker Rod Made of 20CrMo Alloy

2011 ◽  
Vol 295-297 ◽  
pp. 626-630 ◽  
Author(s):  
Yong Jun Bian ◽  
Wei Shi ◽  
Jin Yue Lao ◽  
Jie Chen ◽  
Shu Ling Sun
Keyword(s):  
Stress Corrosion ◽  
Fracture Analysis ◽  
Composition Analysis ◽  
Metal Impurity ◽  
Metallographic Examination ◽  
Service Load ◽  
Sucker Rod ◽  
Chemical Composition Analysis ◽  
Corrosion Pits ◽  
Stress Fatigue

Multiple types of analysis and examinations are applied to analyze the causes of rupture for a sucker rod made of 20CrMo alloy. Based on the results from macro- and micro-fracture analysis, chemical composition analysis, mechanics test and metallographic examination, the generation of cracks can be attributed to the irregularity and impurity in the coating of sucker rod; the stress fatigue from pulling and pressing and the stress corrosion. There is severe banded segregation, non-metal impurity and un-dissolved ferrite in the interior of the rod, meanwhile the poor heat treatment causes the property differences between the surface and core structures of the rod, thus reduces the overall properties of fatigue- and corrosion-resistance. Stress corrosion makes pits from cracks; the expansion of such corrosion pits reduces the size of effective loading area; and the failure to endure service load due to the reduction of loading area finally causes sudden rupture of the rod.

Analysis Analysis and Suggestions on Device Clamp Screw Fracture of 110kV Transmission Line

2014 ◽  
Vol 989-994 ◽  
pp. 69-73
Author(s):  
Xue Xia Xu ◽  
Wei Yong Li ◽  
Guang Xing Zhang ◽  
Yan Ting Feng ◽  
Hao Ke ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Chemical Composition ◽  
Transmission Line ◽  
Heat Processing ◽  
Composition Analysis ◽  
Material Degradation ◽  
Edax Analysis ◽  
Fracture Failure ◽  
Microstructure Observation ◽  
Chemical Composition Analysis

Fracture failure analysis on device clamp screws of one 110kV transmission line has been carried out based on results of macro-observation, pre-tightening test, mechanical property examination, chemical composition analysis, microstructure observation, SEM observation and EDAX analysis. It is concluded that the main reason of the screw fracture lies in misuse material and improper heat processing which led to material degradation. Suggestions are put forward 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.

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