Environmental Effect of Hot Corrosion on the Creep Rupture Properties of a Nickel-Base Superalloy
| Project/Area Number |
61550537
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
YOSHIBA Masayuki Associate Professor, Faculty of Technology, Tokyo Metropolitan Univ., 工学部, 助教授 (30094288)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Nickel-Base Superalloys / Creep Rupture Properties / Hot Corrosion / Gas Turbine / 燃焼ガス |
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| Research Abstract |
In order to clarify the effect of various environmental factors on the creep rupture properties of a Ni-base superalloy subjected to hot corrosion which is encoundered in the hot section components of various fossil fuel combustion engines such as gas turbines, diesel engines and so on, the creep rupture tests were performed in the simulated hot corrosive environment, using the newly manufactured vacuum vessel for controlling the corrosive atmosphere. The results obtained are summarized as follows:
1. Manufacture and Performances of Vacuum Vessel for Controlling Corrosive Atmosphere. In order to ontrol the gas atmospheric condition, a vacuum vessel was newly manufactured with good heat- and corrosion-resistance along with high air resistance, using SUS 310S stainless steel seamless pipe, stainless steel bellows, heat resistant O ring and so on. An endurance temperature and a degree of vacuum of this equipment is approximately 900゜C and 10^<-6> Torr., respectively.
2. Creep Rupture Properties of Ni-base Superalloy in Various Gas Atmospheres and Corrosive Environments. Creep rupture tests were performed of Ni-base Inconel 751 alloy specimens with or without the Na_2SO_4-NaCl synthetic salt coating and in the various gas atmospheres using N_2, O_2 and N_2-O_2 mixture gases. In the case without salt coating, the creep rupture properties were found to be identical regardless of the oxygen partial pressure (pO_2). In the salt coated corrosive environments, on the contrary, the rupture strength and ductility were markedly decreased, depending on the pO_2. In particular, in high pO_2 atmosphere more than about 5x10^<-3> atm. the corrosioninduced strength degradation was more pronounced along with the increased data scatter and brittle fracture manner. This result should be related with a change in the contribution of oxidation in the selective intergranular corrosion behavior. The further investigation about this critical pO_2 is planned.
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Report
(2 results)
Research Products
(5 results)
