Case studies in engineering failure analysis最新文献_第7页

Failure analysis of work rolls of a thin hot strip mill 热轧薄带钢工作辊失效分析

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2015.01.001

Piyas Palit , Hrishikesh R. Jugade , Arvind Kumar Jha , Souvik Das , Goutam Mukhopadhyay

{"title":"Failure analysis of work rolls of a thin hot strip mill","authors":"Piyas Palit , Hrishikesh R. Jugade , Arvind Kumar Jha , Souvik Das , Goutam Mukhopadhyay","doi":"10.1016/j.csefa.2015.01.001","DOIUrl":"10.1016/j.csefa.2015.01.001","url":null,"abstract":"<div><p>In hot rolling mills, premature failure of rolls is a major concern as it adversely affects the mill operation as well as production. Analysis of failed roll materials and actual rolling conditions in service are therefore necessary to understand the roll failure mechanism and thereby improve the wear resistance and extend the service life of rolls.</p><p>The hot strip mill referred here consists of six stands wherein high chromium (Hi-Cr) iron rolls and Indefinite Chilled Double Poured (ICDP) cast iron rolls are being used for finishing rolling of the strips in the last two stands. The thin strip mill produces strips in the thickness range of 1.0–12.7mm. This work describes two different types of roll failure cases and their analysis which was carried out using destructive as well as non-destructive testing techniques (NDT). The cases are as follows:</p><ul><li><span>(a)</span><span><p>Case I: enhanced ICDP bottom roll of fifth stand (F#5) which failed from the neck portion.</p></span></li><li><span>(b)</span><span><p>Case II: analysis of sub-surface defect of ICDP rolls of the last stand (F#6).</p></span></li></ul><p>Destructive testing (including metallography and chemical analysis) was carried out on the failed roll samples in the first case and gross abnormality in microstructure was observed. Some foreign particle/entrapment was observed after dressing of the working surface of roll at 566mm diameter (initial diameter of roll was 620mm and scrap diameter was projected to be 540mm). The chemical composition of the particle was analyzed by a portable X-Ray Fluorescence (XRF) alloy analyzer and it was confirmed that the particle is basically a ferroalloy which was entrapped in the shell of the roll, probably during casting/manufacturing of roll.</p></div>","PeriodicalId":91224,"journal":{"name":"Case studies in engineering failure analysis","volume":"3 ","pages":"Pages 39-45"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csefa.2015.01.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"54176832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Premature failure of dissimilar metal weld joint at intermediate temperature superheater tube 中温过热器管异种金属焊缝过早失效

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2015.03.006

Mohammed Al Hajri, Anees U. Malik , Abdelkader Meroufel, Fahd Al-Muaili

引用次数: 17

Failure of the chassis of roller skates for agonistic figure skating 竞争式花样滑冰轮滑鞋底盘失效

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2014.08.002

Giorgio Olmi

引用次数: 10

Failure analysis of a vibration isolator used in launch vehicle applications 运载火箭用隔振器失效分析

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2014.07.003

S.V.S. Narayana Murty, Sushant K. Manwatkar, P. Ramesh Narayanan

引用次数: 1

Fatigue fracture of cutter blade made of high-speed steel 高速钢刀具叶片疲劳断裂

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2014.10.001

Beata Letkowska, Wlodzimierz Dudzinski, Lukasz Konat

引用次数: 2

A failure study of a locking compression plate implant 锁定加压钢板植入失败的研究

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2015.03.004

Nirajan Thapa , Michael Prayson , Tarun Goswami

引用次数: 25

Evaluation of failures in mechanical crankshafts of automobile based on expert opinion 基于专家意见的汽车机械曲轴失效评估

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2014.11.001

B. Kareem

{"title":"Evaluation of failures in mechanical crankshafts of automobile based on expert opinion","authors":"B. Kareem","doi":"10.1016/j.csefa.2014.11.001","DOIUrl":"10.1016/j.csefa.2014.11.001","url":null,"abstract":"<div><p>In this study, mechanical crankshaft failures for automobiles are evaluated based on experts’ opinion. This was done using data obtained using techniques based on oral interviews and questionnaire administration on mechanical failure of crankshafts from the experts working in the areas of automobile maintenance and crankshafts reconditioning. The data collected were analyzed using statistical methods based on probability. With this technique, probability of failure for each category of automobiles namely private, commercial cars and buses were evaluated. The results obtained show that private cars had lowest failure rate at the initial stage while commercial buses had the highest failure rate. At later periods all categories of automobile crankshafts considered had their failure rates converged steadily with stable reliability. Application of 6-sigma continuous improvement tool to the process indicated a further reliability improvement through improved oil lubrication system, especially in the thrust bearing. This showed that increased enlightenment campaign among the various stakeholders in automobile industries will improve on the choice of reliable mechanical crankshafts.</p></div>","PeriodicalId":91224,"journal":{"name":"Case studies in engineering failure analysis","volume":"3 ","pages":"Pages 25-33"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csefa.2014.11.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"54176814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Failure analysis of the pulleys during the press-fit assembling process 压合装配过程中滑轮失效分析

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2014.11.002

Eva Zdravecká , Miroslav Ondáč , Jana Tkáčová , Marek Vojtko , Ján Slota

引用次数: 3

Failure analysis of axle shaft of a fork lift 某叉车轴轴失效分析

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2015.01.003

Souvik Das, Goutam Mukhopadhyay, Sandip Bhattacharyya

{"title":"Failure analysis of axle shaft of a fork lift","authors":"Souvik Das, Goutam Mukhopadhyay, Sandip Bhattacharyya","doi":"10.1016/j.csefa.2015.01.003","DOIUrl":"10.1016/j.csefa.2015.01.003","url":null,"abstract":"<div><p>An axle shaft of fork lift failed at operation within 296h of service. The shaft transmits torque from discrepancy to wheel through planetary gear arrangement. A section of fractured axle shaft made of induction-hardened steel was analyzed to determine the root cause of the failure. Optical microscopies as well as field emission gun scanning electron microscopy (FEG-SEM) along with energy dispersive spectroscopy (EDS) were carried out to characterize the microstructure. Hardness profile throughout the cross-section was evaluated by micro-hardness measurements. Chemical analysis indicated that the shaft was made of 42CrMo4 steel grade as per specification. Microstructural analysis and micro-hardness profile revealed that the shaft was improperly heat treated resulting in a brittle case, where crack was found to initiate from the case in a brittle mode in contrast to ductile mode within the core. This behaviour was related to differences in microstructure, which was observed to be martensitic within the case with a micro-hardness equivalent to 735HV, and a mixture of non-homogeneous structure of pearlite and ferrite within the core with a hardness of 210HV. The analysis suggests that the fracture initiated from the martensitic case as brittle mode due to improper heat treatment process (high hardness). Moreover the inclusions along the hot working direction i.e. in the longitudinal axis made the component more susceptible to failure.</p></div>","PeriodicalId":91224,"journal":{"name":"Case studies in engineering failure analysis","volume":"3 ","pages":"Pages 46-51"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csefa.2015.01.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"54176850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

Reliability study and simulation of the progressive collapse of Roissy Charles de Gaulle Airport 戴高乐机场累进倒塌可靠性研究与仿真

Case studies in engineering failure analysis Pub Date : 2015-04-01 DOI: 10.1016/j.csefa.2015.03.003

Y. El Kamari , W. Raphael , A. Chateauneuf

引用次数: 19