{"title":"19- 9dl耐热合金带式夹具的应力腐蚀失效","authors":"","doi":"10.31399/asm.fach.aero.c0091533","DOIUrl":null,"url":null,"abstract":"\n A clamp used for securing the hot-air ducting system on fighter aircraft fractured in an area adjacent to a slot near the end of the strap after two or three years of service. The strap was 0.8 mm (0.032 in.) thick, and the V-section was 1.3 mm (0.050 in.) thick; both were made of 19-9 DL heat-resisting alloy. The operating temperature of the duct surrounded by the clamp was 425 to 540 deg C (800 to 1000 deg F). The life of the clamp was expected to equal that of the aircraft. Investigation (visual inspection, chemical analysis, hardness testing, and 540x/2700x images etched with oxalic acid) supported the conclusion that the clamp fractured by SCC because the work metal was sensitized. Sensitization occurred during long-term exposure to the service temperature; the effects of sensitization were intensified as a result of cold forming. Recommendations included using a work metal that is less susceptible to intergranular carbide precipitation.","PeriodicalId":326464,"journal":{"name":"ASM Failure Analysis Case Histories: Air and Spacecraft","volume":"67 10 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Stress-Corrosion Failure of a Strap-Type Clamp Made of 19-9 DL Heat- Resisting Alloy\",\"authors\":\"\",\"doi\":\"10.31399/asm.fach.aero.c0091533\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n A clamp used for securing the hot-air ducting system on fighter aircraft fractured in an area adjacent to a slot near the end of the strap after two or three years of service. The strap was 0.8 mm (0.032 in.) thick, and the V-section was 1.3 mm (0.050 in.) thick; both were made of 19-9 DL heat-resisting alloy. The operating temperature of the duct surrounded by the clamp was 425 to 540 deg C (800 to 1000 deg F). The life of the clamp was expected to equal that of the aircraft. Investigation (visual inspection, chemical analysis, hardness testing, and 540x/2700x images etched with oxalic acid) supported the conclusion that the clamp fractured by SCC because the work metal was sensitized. Sensitization occurred during long-term exposure to the service temperature; the effects of sensitization were intensified as a result of cold forming. Recommendations included using a work metal that is less susceptible to intergranular carbide precipitation.\",\"PeriodicalId\":326464,\"journal\":{\"name\":\"ASM Failure Analysis Case Histories: Air and Spacecraft\",\"volume\":\"67 10 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"ASM Failure Analysis Case Histories: Air and Spacecraft\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.31399/asm.fach.aero.c0091533\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"ASM Failure Analysis Case Histories: Air and Spacecraft","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.31399/asm.fach.aero.c0091533","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Stress-Corrosion Failure of a Strap-Type Clamp Made of 19-9 DL Heat- Resisting Alloy
A clamp used for securing the hot-air ducting system on fighter aircraft fractured in an area adjacent to a slot near the end of the strap after two or three years of service. The strap was 0.8 mm (0.032 in.) thick, and the V-section was 1.3 mm (0.050 in.) thick; both were made of 19-9 DL heat-resisting alloy. The operating temperature of the duct surrounded by the clamp was 425 to 540 deg C (800 to 1000 deg F). The life of the clamp was expected to equal that of the aircraft. Investigation (visual inspection, chemical analysis, hardness testing, and 540x/2700x images etched with oxalic acid) supported the conclusion that the clamp fractured by SCC because the work metal was sensitized. Sensitization occurred during long-term exposure to the service temperature; the effects of sensitization were intensified as a result of cold forming. Recommendations included using a work metal that is less susceptible to intergranular carbide precipitation.