Vol.9 No.2 AASP17 (125-126-127-128-129-130-131-132-133-134-135-136-137-138-139-140-141-142) NT85 |
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Academic Articles | |||||
Regular Paper | Vol.9 No.2 (2017) p.91 - p.96 | ||||
Evaluation of environmental compatibility of EHP (extra high purity) using austenitic stainless steel cladding material |
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Junji Etoh1, Takaki Ashida1, Takamasa Ochiai1, Kiyoshi Kiuchi1, Masayuki Takizawa1, Junpei Nakayama2 | |||||
1 Mitsubishi Research Institute, Inc., 10-3, Nagatacho 2-Chome, Chiyoda-Ku, Tokyo 100-8141, JAPAN
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Abstract | |||||
The resistance to environment-assisted cracking (EAC) like SCC (stress corrosion cracking) and aging embrittlement are the most important problems on the materials performance of type 316L steel used in the advanced nuclear power plants. Extra high purity, grade type 25Cr-35Ni EHP, austenitic stainless alloy was developed by means of minimizing impurity using the special melting technology. It has the excellent corrosion resistance in LWR environments and high temperature steam under gamma ray irradiation. In this research, cladding technology of type 25Cr-35Ni EHP alloy on the base metal of type 316L steel is developed for reactor core materials by the diffusion bonding method using hot rolling. The corrosion resistance was tested by aging up to 600 degrees in Ar under gamma-ray irradiation. The effect of cladding and aging embrittlement of type 316L steel due to sigma phase precipitation is evaluated by Charpy impact tests. From these results, it was clarified that the resistance to corrosion and aging embrittlement of type 316L steel are possible to improve by including cladding of type 25Cr-35Ni EHP alloy, of a thickness of more than 2 mm . The cladding of EHP alloy is considered to be one of the most widely used materialtechnology for preventing the aging degradation of austenitic stainless steels like type 316L used in current nuclear power plants. |
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Keywords | |||||
Extra high purity, Austenitic stainless steel, Corrosion, Environmentally- assisted cracking, Cladding material, Charpy impact test | |||||
Full Paper: PDF
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