141 PWSCC SSRT Takuyo Yamada Nobuo Totsuka Goro Chiba Koji Arioka pressurized water reactors, PWRs primary water stress corrosion cracking, PWSCC360 slow strain rate technique, SSRTconstant load test, CLT 23 SCC 152340030,000 SSRTtrans granular, TGSCCTGSCC 1.22.010,000 40010,000SSRT 23400 SCC40030,000 1523SCC Abstract Keywords
142 1. stress corrosion cracking, SCC otsuka 1 Smialowska 2-3 Andresen 4 SCC PWRs SUS304SUS316 SCC PWRs290 320 5-9 SCC MgCl2H2SSCC 10-13 SCC 12-13 PWR SCCPWSCC 14 15 SSRTCLT SCS14APWSCC SSRTPWSCC SSRT 400 30,000SSRT SCC 16 2. 2.1 JIS SCS14A, ASTM CFM 15 23FF15F23 energy dispersive X-ray, EDX CrNiSi Mn SiFF15F23 MnFF15F23 SUS316 a mass F23 F15 F8 C 0.08 0.044 0.039 0.047 Si 1.50 1.46 1.07 0.79 Mn 1.50 0.68 0.84 0.90 P 0.040 0.029 0.023 0.026 S 0.040 0.016 0.008 0.017 Ni 9-12 9.57 9.28 10.67 Cr 18-21 20.02 18.80 18.85 Mo 2-3 2.23 2.14 2.22 N - 0.0501 0.0558 0.0562 a
143 表２ 試料 F23, F15, F8 の各相の化学組成b mass 光学顕微鏡による供試材のミクロ組織を図１ ３ Fe Ni Cr Si Mo Mn に示す F23 F15 F８はともに典型的な鋳造２相 F23α 63.78 5.57 25.52 1.67 2.91 0.55 ステンレス鋼の組織を呈している F15α 64.67 5.17 24.62 1.35 3.39 0.80 F8α 63.55 5.54 25.32 1.05 3.65 0.89 F23γ 66.28 9.46 20.13 1.40 1.84 0.89 F15γ 66.98 9.15 19.64 1.24 2.02 0.97 F8γ 65.82 10.0 20.03 0.94 2.20 1.01 b 各相６点測定の平均値 加速電圧20kV スタンダードレス法により定量 図１ F23の光学顕微鏡組織 図２ F15の光学顕微鏡組織 図３ F８の光学顕微鏡組織
144 2.2 3. SCS14A 400 30,000 2.3 SSRTCLT 1200 SSRTCLTPWR 500 ppm B +ppm Li 2.750.3ppm 360 CLT 3600.2% 0.2 1.22.0 SSRTscanning electron microscope, SEM SEM SSRT CLT 360C 360C 360C mm PWR1 5.010-7 S -1 PWR1 8.310-5 S -1 1.22.0 3.1 F23SSRT TGSCC PWRSCC SCC F2340010,000 SSRT TGSCC 40010,000 HV=690 13 SCC 18 SCC 14-16
145 図５ 図６ 未時効材におけるSSRT後の破面の脆性破面部分の典型例 時効材におけるSSRT後の破面の脆性破面部分の典型例
146 PWRSSRT TGSCC SCC SCC SSRT SCC SCC SCC 3.2 SSRT 14 SSRT 100 5002,000 SCC CGR SSRT CGR SSRT Ts1/2Ascct failure 1 TsAscct failure SSRT CGR SSRT SCC F23 SSRT SCC 17 SCC
147 1011F F15F23SCC SCC F F 17 10 CGR SSRT h 3.3 SCC SCC SCC 40030,000 11 CGR SSRT
148 3.4 SCC 360 1240010,000 0.2% 0.2 1.22.0 13 1.62.010,000 SSRT 14 SSRT O 12 23360 13 F23
149 14 F2340010,000 4. PWRs SCS14A 81523 400 30,000 360SSRTCLT PWSCC 1SCS14A360PWR SCCPWSCC 23 400 2 PWSCC 40030,00015 23 PWSCC SCC 3SSRT TGSCC TGSCC TGSCC 4CLT23 0.21.6400 10,0001.2 / SSRT
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