发布求助
文献互助 智能选刊 最新文献

ASM Failure Analysis Case Histories: Air and Spacecraft最新文献

筛选
英文 中文
Stress-Corrosion Cracking of a T-Bolt t型螺栓的应力腐蚀开裂
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c0048616
{"title":"Stress-Corrosion Cracking of a T-Bolt","authors":"","doi":"10.31399/asm.fach.aero.c0048616","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c0048616","url":null,"abstract":"\u0000 A T-bolt was part of the coupling for a bleed air duct of a jet engine on a transport plane. Specifications required that the 4.8 mm diam component be made of AISI type 431 stainless steel and heat treated to 44 HRC. The operating temperature of the duct is 425 to 540 deg C (800 to 1000 deg F), but that of the bolt is lower. The T-bolt broke after three years of service. The expected service life was equal to that of the aircraft. It was found that the bolt broke as a result of SCC. Thermal stresses were induced into the bolt by intermittent operation of the jet engine. Mechanical stresses were induced by tightening of the clamp around the duct, which in effect acted to straighten the bolt. The action of these stresses on the carbides that precipitated in the grain boundaries resulted in fracture of the bolt. Due to the operating temperatures of the duct near the bolt, the material was changed to A-286, which is less susceptible to carbide precipitation. The bolt is strengthened by shot peening and rolling the threads after heat treatment. Avoiding temperatures in the sensitizing range is desirable, but difficult to ensure because of the application.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114205204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Breakage of Main Undercarriage Axle of Landing Gear System of an Aircraft Under Simulated Testing 某型飞机起落架系统主底盘轴在模拟试验中的断裂
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c9001555
A. Das, B. Thippeswamy, J. Prasad
{"title":"Breakage of Main Undercarriage Axle of Landing Gear System of an Aircraft Under Simulated Testing","authors":"A. Das, B. Thippeswamy, J. Prasad","doi":"10.31399/asm.fach.aero.c9001555","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c9001555","url":null,"abstract":"\u0000 One main undercarriage axle made of high strength alloy steel was subjected to simulated fatigue test for 6000 h of service. After only 300 h it broke in two along the sharp radius. The fracture revealed a coarse, irregular, and brittle surface before final fracture by thick angular shear lip zone. The presence of micropores in the cleavage facets as well as at the grain boundaries and hairline type crack indications under SEM examination were all suggestive of hydrogen embrittlement. On the basis of investigation results and observations, it was concluded that the transverse breakage of the axle had occurred intergranularly in a brittle manner, possibly, initiated by a shallow zone of fatigue along the sharp radius acting as stress riser.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127248578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Failure of a Throttle-Arm Assembly Because of Thread-Root Cracks in the HAZ 由于热影响区螺纹根部裂纹导致的节流臂总成失效
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c0047541
{"title":"Failure of a Throttle-Arm Assembly Because of Thread-Root Cracks in the HAZ","authors":"","doi":"10.31399/asm.fach.aero.c0047541","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c0047541","url":null,"abstract":"\u0000 A throttle arm of an aircraft engine fractured and caused loss of engine control. The broken part consisted of a 6.4-mm (1/4-in.) diam medium-carbon steel rod with a thread to fit a knurled brass nut that was inserted into the throttle knob. The threaded rod had been welded to the throttle-linkage bar by an assembly-weld deposit made on the rod adjacent to the threaded portion. The fracture surface exhibited a coarse-grain brittle texture with an initiating crack at a thread root. The throttle-arm failed by brittle fracture because of the presence of cracks at the thread roots that were within the HAZ of the adjacent weld deposit. The heat of welding had generated a coarse-grain structure with a weak grain-boundary network of ferrite that had not been corrected by postweld heat treatment. The combination of the cracks and this unfavorable microstructure provided a weakened condition that resulted in catastrophic, brittle fracture under normal applied loads. The design was altered to eliminate the weld adjacent to the threaded portion of the rod.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121273672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Failure of Maraging Steel Breech Bolt Assemblies 马氏体时效钢后膛螺栓组件失效
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c9001910
M. Pepi
{"title":"Failure of Maraging Steel Breech Bolt Assemblies","authors":"M. Pepi","doi":"10.31399/asm.fach.aero.c9001910","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c9001910","url":null,"abstract":"\u0000 Breech bolt assemblies from the Gatling guns used on fighter aircraft failed during firing tests. Metallography of the failed components revealed considerable decarburization which resulted in a loss of surface hardness. It was also determined that the maraging steel components were not in the nitrided condition as was required. This resulted in lower wear and fatigue resistance. These components also had a silicon content nearly double of that specified. The high silicon content lowered the notch tensile strength and toughness of the components.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128322411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Fatigue Cracking of a Forged 4337 Steel Master Connecting Rod Because of Nonmetallic Inclusions 非金属夹杂物导致锻造4337钢主连杆疲劳开裂
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c0047856
{"title":"Fatigue Cracking of a Forged 4337 Steel Master Connecting Rod Because of Nonmetallic Inclusions","authors":"","doi":"10.31399/asm.fach.aero.c0047856","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c0047856","url":null,"abstract":"\u0000 The master connecting rod of a reciprocating aircraft engine revealed cracks during routine inspection. The rods were forged from 4337 (AMS 6412) steel and heat treated to a specified hardness of 36 to 40 HRC. H-shaped cracks in the wall between the knuckle-pin flanges were revealed by visual examination. The cracks were originated as circumferential cracks and then propagated transversely into the bearing-bore wall. No inclusions in the master rod were detected by magnetic-particle and x-ray inspection. Three large inclusions lying approximately parallel to the grain direction and fatigue beach marks around two of the inclusions were revealed by macroscopic examination of the fracture surface. Large nonmetallic inclusions that consisted of heavy concentrations of aluminum oxide (Al2O3) were revealed by microscopic examination of a section through the fracture origin. The forging vendors were notified about the excess size of the nonmetallic inclusions in the master connecting rods and a nondestructive-testing procedure for detection of large nonmetallic inclusions was established.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122884237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Failure Investigation of a Structural Component of the Main Landing Gear of a Transport Aircraft 某运输机主起落架结构部件失效研究
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c9001706
A. M. Abdel-latif, M. Roth, M. Yanishcvsky
{"title":"Failure Investigation of a Structural Component of the Main Landing Gear of a Transport Aircraft","authors":"A. M. Abdel-latif, M. Roth, M. Yanishcvsky","doi":"10.31399/asm.fach.aero.c9001706","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c9001706","url":null,"abstract":"\u0000 The truck beam of the left main landing gear (MGL) of a Boeing 707 airplane collapsed on the ground just after the aircraft was unloaded and refueled. The investigation revealed that failure was caused by the propagation of an intergranular crack originating from the bottom of the pit. The crack reached the critical size and caused failure by stress-corrosion cracking (SCC) under static loading conditions in service. The failed beam was protected by a well adhering paint system. However, the presence of adequate amounts of corrosion preventive compound films (CPC) on the surfaces of the failed beam could not be conclusively established because of the long term service exposure and presence of lubricants.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124149528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Cracks in Forged Aircraft Wheel Halves That Originated From Forging Defects 由锻造缺陷引起的锻造飞机轮半裂纹
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c0047165
{"title":"Cracks in Forged Aircraft Wheel Halves That Originated From Forging Defects","authors":"","doi":"10.31399/asm.fach.aero.c0047165","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c0047165","url":null,"abstract":"\u0000 Two outboard main-wheel halves (aluminum alloy 2014-T6 forged) from a commercial aircraft were removed from service because of failure. One wheel half was in service for 54 days and had made 130 landings (about 1046 roll km, or 650 roll mi) when crack indications were discovered during eddy-current testing. The flange on the second wheel half failed after only 31 landings, when about 46 cm (18 in.) of the flange broke off as the aircraft was taxiing. Stains on the fracture surfaces were used to determine when cracking was initiated. The analysis (visual inspection, liquid penetrant inspection, and micrographs with deep etching in aqueous 20% sodium hydroxide) supported the conclusion that failure on both wheel halves was by fatigue caused by a forging defect resulting from abnormal transverse grain flow. The crack in the first wheel half occurred during service, and the surfaces became oxidized. Because the fracture surface of the second wheel half had chromic acid stains, it was obvious that the forging defect was open to the surface during anodizing. No recommendations were made except to notify the manufacturer.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134516969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Aluminum Alloy 7178-T6 Aircraft Deck Plate That Failed in Service by Fatigue Cracking 7178-T6铝合金飞机甲板板疲劳开裂失效
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c0047076
{"title":"Aluminum Alloy 7178-T6 Aircraft Deck Plate That Failed in Service by Fatigue Cracking","authors":"","doi":"10.31399/asm.fach.aero.c0047076","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c0047076","url":null,"abstract":"\u0000 Two cracks were discovered in a deck plate of an aircraft during overhaul and repair after 659 h of service. The cracks were on opposite sides of the deck plate in the flange joggles. The plate had been formed from 7178-T6 aluminum alloy sheet. Analysis (visual inspection, 0.2x/2x/2.3x electron microscope fractographs, hardness testing, and electrical conductivity testing) supported the conclusions that the failure was caused by fatigue cracks originating on the inside curved surface of the flanges. The cracks had initiated in surface defects caused by either corrosion pitting or forming notches, acting in combination with lateral forces evidenced by the moderate distortion of the fastener holes. Recommendations included eliminating the surface defects by revised cleaning and/or forming procedures. Revised design and installation should also alleviate the lateral forces.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":" 13","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132094488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Failure of Aircraft Engine Crankshaft 飞机发动机曲轴故障
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c9001019
C. Craft
{"title":"Failure of Aircraft Engine Crankshaft","authors":"C. Craft","doi":"10.31399/asm.fach.aero.c9001019","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c9001019","url":null,"abstract":"\u0000 A broken aircraft crankshaft and a severely damaged main brass bearing were examined to determine whether engine failure was initiated in the bearing or in the crankshaft. The steel crankshaft failure was a classical fatigue fracture. The bearing had been subjected to extremely high temperatures, as indicated by melting in the brass components and the extreme distortion in the rollers. Microscopic examination on the crankshaft material showed it to be a good quality steel. On the other hand, the chromium plate was thick, porous, and cracked in many places, including the point of the main fatigue crack. It was concluded that the over-all failure was initiated in the crankshaft, and the failure of the bearing resulted from that failure.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116295489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Fatigue Cracking of a Stainless Steel Elbow Assembly at a Welded Joint in a High-Stress Region 高应力区焊接接头处不锈钢弯头组件的疲劳开裂
ASM Failure Analysis Case Histories: Air and Spacecraft Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.aero.c0089722
{"title":"Fatigue Cracking of a Stainless Steel Elbow Assembly at a Welded Joint in a High-Stress Region","authors":"","doi":"10.31399/asm.fach.aero.c0089722","DOIUrl":"https://doi.org/10.31399/asm.fach.aero.c0089722","url":null,"abstract":"\u0000 A welded elbow assembly (AISI type 321 stainless steel, with components joined with ER347 stainless steel filler metal by gas tungsten arc welding) was part of a hydraulic-pump pressure line for a jet aircraft. The other end of the tube was attached to a flexible metal hose, which provided no support and offered no resistance to vibration. The line was leaking hydraulic fluid at the nut end of the elbow. Investigation supported the conclusion that failure was by fatigue cracking initiated from a notch at the root of the weld and was propagated by cyclic loading of the tubing as the result of vibration and inadequate support of the hose assembly. Recommendations included changing the joint design from a cylindrical lap joint to a square-groove butt joint. Also, an additional support was recommended for the hose assembly to minimize vibration at the elbow.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116447968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信