ASM Failure Analysis Case Histories: Power Generating Equipment最新文献_第2页

Turbine Blade Failure 涡轮叶片失效

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c9001412

{"title":"Turbine Blade Failure","authors":"","doi":"10.31399/asm.fach.power.c9001412","DOIUrl":"https://doi.org/10.31399/asm.fach.power.c9001412","url":null,"abstract":"\u0000 Three blades from 45,000 kW, 3,000 rpm turbine were received for examination, comprising the root of blade 28, blade 89 showing a crack in one of the root teeth, and blade 106 which was free from defects. Microscopic examination of the blade material showed it to be a ferritic stainless steel of the type commonly used for turbine blades. A number of non-metallic inclusions were present which had been drawn into threads in rolling; these appeared to consist largely of duplex silicates. The failure of blade 28 was the result of the development of a creeping crack. Magnetic crack examination of blade 89 revealed a crack in a tooth in an identical position to the start of the crack in blade 28 but on the opposite, i.e., steam inlet, side of the blade. Similar examination of blade 106 did not reveal any cracks. Cracking was associated with unsatisfactory bedding of the blade teeth on the faces of the wheel grooves. It was concluded that the blade failures were due primarily to over-loading of the individual blade teeth due to incorrect fitting in the wheel. Vibration was an important contributory factor, as it resulted in the imposition of fluctuating stresses on the overloaded teeth. Non-metallic inclusions in the blade material playing a minor part.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114906716","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: 1

High-Temperature Degradation of a Gas Turbine Transition Duct 燃气轮机过渡管道的高温退化

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c0091754

引用次数: 0

Stress-Corrosion Cracking of Alloy X-750 Jet Pump Beams X-750合金喷射泵梁的应力腐蚀开裂

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c0091659

引用次数: 0

Failure of Steam Pipe at Local Defects 蒸汽管道在局部缺陷处失效

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c9001422

引用次数: 0

Failure of a Reheat Steam Piping Line at a Power-Generating Station 发电厂再热蒸汽管路故障

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c0048801

{"title":"Failure of a Reheat Steam Piping Line at a Power-Generating Station","authors":"","doi":"10.31399/asm.fach.power.c0048801","DOIUrl":"https://doi.org/10.31399/asm.fach.power.c0048801","url":null,"abstract":"\u0000 A 75 cm OD x 33 mm thick pipe in a horizontal section of a hot steam reheat line ruptured after 15 years in service. The failed section was manufactured from rolled plate of material specification SA387, grade C. The longitudinal seam weld was a double butt-weld that was V-welded from both sides and failure was found to propagate along the longitudinal seam and its HAZ. The fracture surface near the inner wall of the pipe was found to have a bluish gray appearance, while the fracture surface near the outer wall was rust colored (oxides). The transverse-to-the-weld specimen from the longitudinal seam weld was revealed to have lower elongation and a shear type failure rather than the cup-cone failures. It was concluded that the welded longitudinal seam exhibited embrittlement. A low-ductility intergranular fracture that progressed through the weld metal was revealed by scanning electron microscopy. The cracks were revealed to be in existence for some time before the final failure which was indicated by the extent and amount of corrosion products. It was concluded that low ductility was responsible for the original initiation of cracks in the pipe.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126726326","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

Thermal Exposure Assessment by Quantitative Microscopy and Selective Etching 定量显微镜和选择性蚀刻热暴露评估

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c9001571

G. V. Vander Voort

{"title":"Thermal Exposure Assessment by Quantitative Microscopy and Selective Etching","authors":"G. V. Vander Voort","doi":"10.31399/asm.fach.power.c9001571","DOIUrl":"https://doi.org/10.31399/asm.fach.power.c9001571","url":null,"abstract":"\u0000 The accident at Three Mile Island Unit No. 2 on 28 March 1979 was the worst nuclear accident in US history. By Jan 1990, it was possible to electrochemically machine coupons from the lower head using a specially designed tool. The specimens contained the ER308L stainless steel cladding and the A533 Grade B plate material to a depth of about mid-wall. The microstructures of these specimens were compared to that of specimens cut from the Midland, Michigan reactor vessel, made from the same grade and thickness but never placed in service. These specimens were subjected to known thermal treatments between 800 and 1100 deg C for periods of 1 to 100 min. Microstructural parameters in the control specimens and in those from TMI-2 were quantified. Selective etchants were used to better discriminate desired microstructural features, particularly in the cladding. This report is a progress report on the quantification of changes in both the degree of carbide precipitation and delta ferrite content and shape in the cladding as a function of temperature and time to refine the estimates of the maximum temperatures experienced.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126925038","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 Copper Alloy C27000 Innercooler Tubes for Air Compressors Because of Dezincification 空气压缩机C27000铜合金内冷管因脱锌而失效

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c0046469

{"title":"Failure of Copper Alloy C27000 Innercooler Tubes for Air Compressors Because of Dezincification","authors":"","doi":"10.31399/asm.fach.power.c0046469","DOIUrl":"https://doi.org/10.31399/asm.fach.power.c0046469","url":null,"abstract":"\u0000 After about 17 years in service, copper alloy C27000 (yellow brass, 65% Cu) innercooler tubes in an air compressor began leaking cooling water, causing failure and requiring replacement. The tubes were 19 mm in diam and had a wall thickness of 1.3 mm (0.050 in.). The cooling water that flowed through the tubes was generally sanitary (chlorinated) well water; however, treated recirculating water was sometimes used. Analysis (visual inspection, 9x and 75x unetched micrographs, and spectrochemical analysis) showed a thick uniform layer of porous, brittle copper on the inner surface of the tube, extending to a depth of about 0.25 mm (0.010 in.) into the metal, plug-type dezincification extending somewhat deeper into the metal. This supported the conclusion that failure of the tubes was the result of the use of an uninhibited brass that has a high zinc content and therefore is readily susceptible to dezincification. Recommendations included replacing the material with copper alloy C68700 (arsenical aluminum brass), which contains 0.02 to 0.06% As and is highly resistant to dezincification. Copper alloy C44300 (inhibited admiralty metal) could be an alternative selection for this application; however, this alloy is not as resistant to impingement attack as copper alloy C68700.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126436257","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

Investigation of Superheated Steam Push Rod Spindles 过热蒸汽推杆主轴的研究

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c9001208

F. Naumann, F. Spies

{"title":"Investigation of Superheated Steam Push Rod Spindles","authors":"F. Naumann, F. Spies","doi":"10.31399/asm.fach.power.c9001208","DOIUrl":"https://doi.org/10.31399/asm.fach.power.c9001208","url":null,"abstract":"\u0000 A spindle made of hardenable 13% chromium steel X40 Cr13 (Material No. 1.4034) that was fastened to a superheated steam push rod made of high temperature structural steel 13Cr-Mo44 (Material No. 1.7335) by means of a convex fillet weld, fractured at the first operation of the rod directly next to the weld bead. Investigation showed that the fracture of the superheated steam push rod spindle was caused by hardening and hardening crack formation in the weld seams and adjoining areas. It would have been preferable to avoid welding near the cross sectional transitions altogether in consideration of the crack sensitivity of high hardenability steels. If for some reason this was not possible, then all precautions should have been taken that are applicable to the particular steel, such as preheating, slow cooling and stress relief tempering after welding. The selection of an austenitic additive material should have been considered because it could have equalized stresses due to its high elongation. Most probably, however, a material of lower hardenability should have been selected for the spindle if high operating properties were of paramount importance.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121530377","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 in Steam Turbine Blades 汽轮机叶片故障

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c9001193

F. Vodopivec

引用次数: 0

Failure Analysis of a Set of 1CrMoV Studs From a Steam Turbine and Techniques for Its Assessment 汽轮机1CrMoV螺栓失效分析及评估技术

ASM Failure Analysis Case Histories: Power Generating Equipment Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.power.c9001004

J. Hickey, J. Bulloch

{"title":"Failure Analysis of a Set of 1CrMoV Studs From a Steam Turbine and Techniques for Its Assessment","authors":"J. Hickey, J. Bulloch","doi":"10.31399/asm.fach.power.c9001004","DOIUrl":"https://doi.org/10.31399/asm.fach.power.c9001004","url":null,"abstract":"\u0000 The results of a failure analysis of a series of Cr-Mo-V steel turbine studs which had experienced a service lifetime of some 50,000 h are described. It was observed that certain studs suffered complete fracture while others showed significant defects located at the first stress bearing thread. Crack extension was the result of marked creep embrittlement and reverse temper embrittlement (RTE). Selected approaches were examined to assess the effects of RTE on the material toughness of selected studs. It was observed that Auger electron microscopy results which indicated the extent of grain boundary phosphorus segregation exhibited a good relationship with ambient temperature Charpy data. The electrochemical polarization kinetic reactivation, EPR, approach, however, proved disappointing in that the overlapping scatter in the minimum current density, Ir, for an embrittled and a non-embrittled material was such that no clear decision of the toughness properties was possible by this approach. The initial results obtained from small punch testing showed good agreement with other reported data and could be related to the FATT. Indeed, this small punch test, combined with a miniature sample sampling method, represents an attractive approach to the toughness assessment of critical power plant components.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122915793","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