ASM Failure Analysis Case Histories: Failure Modes and Mechanisms最新文献_第6页

Biologically Influenced Corrosion of Stainless Steel Welds by Water 水对不锈钢焊缝的生物影响腐蚀

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c9001683

C. Jenkins, D. Doman

{"title":"Biologically Influenced Corrosion of Stainless Steel Welds by Water","authors":"C. Jenkins, D. Doman","doi":"10.31399/asm.fach.modes.c9001683","DOIUrl":"https://doi.org/10.31399/asm.fach.modes.c9001683","url":null,"abstract":"\u0000 Corrosion in a closed-loop cooling water system constructed of austenitic stainless steel occurred during an extended lay up of the system with biologically contaminated water. The characteristics of the failure were those of microbiologically influenced corrosion (MIC). The corrosion occurred at welds and consisted of large subsurface void formations with pinhole penetrations of the surfaces. Corrosive attack initiated in the heat affected zones of the welds, usually immediately adjacent to fusion lines. Stepwise grinding, polishing, and etching through the affected areas revealed that voids generally grew in the wrought material by uniform general corrosion. Tunneling or worm-holing was also observed, whereby void extension occurred by initiating daughter voids probably at flaws or other inhomogeneities. Selective attack occurred within the fusion zone, i.e., within the cast two-phase structure of the weld filler itself. The result was a void wall which consisted of a rough and porous ferritic material, a consequence of preferential attack of the austenitic phase and slightly lower rate of corrosive attack of the ferrite phase. The three-dimensional spongy surface was studied optically and with the scanning electron microscope.","PeriodicalId":231268,"journal":{"name":"ASM Failure Analysis Case Histories: Failure Modes and Mechanisms","volume":"17 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":"116646562","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

Corroded Pipe Section of Oil Burner for Superheated Steam Generator 过热蒸汽发生器油燃烧器管段腐蚀

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c9001240

F. Naumann, F. Spies

引用次数: 0

Evaluation of Alloys for Use in 81-mm Mortar Tubes 81毫米迫击炮管用合金的评价

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c0047010

{"title":"Evaluation of Alloys for Use in 81-mm Mortar Tubes","authors":"","doi":"10.31399/asm.fach.modes.c0047010","DOIUrl":"https://doi.org/10.31399/asm.fach.modes.c0047010","url":null,"abstract":"\u0000 When bulging occurred in mortar tubes made of British I steel during elevated-temperature test firing, a test program was formulated to evaluate the high-temperature properties (at 540 to 650 deg C, or 1000 to 1200 deg F) of the British I steel and of several alternative alloys including a maraging steel (18% Ni, grade 250), a vanadium-modified 4337 gun steel (4337V), H19 tool steel, and high-temperature alloys Rene 41, Inconel 718, and Udimet 630. All the alloys evaluated had been used in mortar tubes previously or were known to meet the estimated minimum yield strength. The alloys fall in this order of decreasing strengths: Udimet 630, Inconel 718, Rene 41, H19 tool steel, British I steel, 4337V gun steel, and maraging steel. When cycled between room temperature and 540 to 650 deg C (1000 to 1200 deg F), only Udimet 630, Inconel 718, and Rene 41 retained yield strengths higher than the minimum. Also, these three alloys maintained high strengths over the tested range, whereas the others decreased in yield strength as cycling progressed. Analysis showed Inconel 718 was considered best suited for 81-mm mortar tubes, and widespread industrial use ensured its availability.","PeriodicalId":231268,"journal":{"name":"ASM Failure Analysis Case Histories: Failure Modes and Mechanisms","volume":"179 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":"122457742","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 Main Steam Line of a Power-Generating Station 电站主蒸汽管路故障

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c0048846

{"title":"Failure of a Main Steam Line of a Power-Generating Station","authors":"","doi":"10.31399/asm.fach.modes.c0048846","DOIUrl":"https://doi.org/10.31399/asm.fach.modes.c0048846","url":null,"abstract":"\u0000 A main steam pipe was found to be leaking due to a large circumferential crack in a pipe-to-fitting weld in one of two steam leads between the superheater outlet nozzles and the turbine stop valves (a line made of SA335-P22 material). The main crack surface was found to be rough, oriented about normal to the outside surface, and had a dark oxidized appearance. The cracking was found to be predominantly intergranular. Distinct shiny bands that etched slower than the remainder of the sample at the top of each individual weld bead were revealed by microscopic examination. These bands were found contain small cracks and microvoids. A mechanism of intergranular creep rupture at elevated temperature was identified as a result of a series of stress-rupture and tensile tests. It was revealed by the crack shape that cracking initiated on the pipe exterior, then propagated inward and in the circumferential direction in response to a bending moment load. It was concluded that the primary cause of failure was the occurrence of bending stresses that exceeded the stress levels predicted by design calculations and that were higher than the maximum allowable primary membrane stress.","PeriodicalId":231268,"journal":{"name":"ASM Failure Analysis Case Histories: Failure Modes and Mechanisms","volume":"C-27 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132571670","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

Radiographic Inspection for Creep Fissures in Reformer-Furnace Tubes 转化炉管蠕变裂纹的射线检测

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c0060144

{"title":"Radiographic Inspection for Creep Fissures in Reformer-Furnace Tubes","authors":"","doi":"10.31399/asm.fach.modes.c0060144","DOIUrl":"https://doi.org/10.31399/asm.fach.modes.c0060144","url":null,"abstract":"\u0000 Two steam-methane reformer furnaces were subjected to short-time heat excursions because of a power outage, which resulted in creep bulging in the Incoloy 800 outlet pigtails, requiring complete replacement. Each furnace had three cells, consisting of 112 vertical tubes per cell, each filled with a nickel catalyst. The tubes were centrifugally cast from ASTM A297, grade HK-40 (Fe-25Cr-20Ni-0.40C), heat-resistant alloy. The tube was concluded after metallurgical inspection to have failed from creep rupture (i.e., stress rupture). A project for detecting midwall creep fissuring was instigated as a result of the failure. It was concluded after laboratory radiography and macroexamination that if the fissure were large enough to show on a radiograph, either with or without the catalyst, the tube could be expected to fail within one year. The set up for in-service radiograph examination was described. The tubes of the furnace were radiographed during shut down and twenty-four tubes in the first furnace and 53 in the second furnace showed significant fissuring. Although, radiography was concluded to be a practical technique to provide advance information, it was limited to detecting fissures caused by third-stage creep in tubes because of the cost involved in removing the catalysts.","PeriodicalId":231268,"journal":{"name":"ASM Failure Analysis Case Histories: Failure Modes and Mechanisms","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":"132913365","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

Brittle Fracture of a Roll-Assembly Sleeve Due to Improper Microstructure 轧辊组套因微观组织不当而脆性断裂

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c0047140

引用次数: 0

The Role of Metallography and Fractography in the Analysis of Gun Tube Failures 金相学和断口学在炮管失效分析中的作用

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c9001671

J. Faller, W. C. Simmons

引用次数: 0

Deformation of the Rotor Winding of a Turbo Alternator: An Extreme Example of “Copper Shortening” 涡轮发电机转子绕组的变形:一个“铜缩短”的极端例子

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c9001487

引用次数: 0

Stress Corrosion Cracking Failures in Components Made of Austenitic Chromium Nickel Steels 奥氏体铬镍钢构件的应力腐蚀开裂失效

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c9001163

Egon Kauczor

引用次数: 0

Embrittlement of a Titanium Heater Tube 钛加热管的脆化

ASM Failure Analysis Case Histories: Failure Modes and Mechanisms Pub Date : 2019-06-01 DOI: 10.31399/asm.fach.modes.c0048757

引用次数: 0