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Qunjia Peng - One of the best experts on this subject based on the ideXlab platform.

  • environmentally assisted crack growth in one dimensionally cold worked Alloy 690tt in primary water
    Corrosion Science, 2012
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Juan Hou, Toshio Yonezawa, Zhaoen Zhang, Fa Huang, Enhou Han
    Abstract:

    Abstract Environmentally assisted crack growth in thermally treated Alloy 690 cold worked one-dimensionally to the thickness reduction of 25% in primary water was investigated. In the water at 50 °C and dissolved hydrogen (DH) of 2.7–2.9 ppm, the Alloy showed a crack growth rate of −9  mm/s at a stress intensity factor of 35 MPa√m. In the water at 340 °C, stress corrosion crack growth rate of −8  mm/s was observed in the Alloy over a DH range of 0.37–2.6 ppm. Further, it was found that hydrogen could promote SCC growth when increasing DH from a very low level.

  • effects of cold working path on strain concentration grain boundary microstructure and stress corrosion cracking in Alloy 600
    Corrosion Science, 2011
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Jiazhen Wang, W Ke
    Abstract:

    Grain boundary microstructure, strain distribution and stress corrosion cracking (SCC) in one dimensional (1D), two dimensional (2D) and three dimensional (3D) cold worked Alloy 600 were investigated. The cold working decreased the annealing twins and increased low angle boundaries. 2D cold working caused lower strain concentration at grain boundaries than 1D and 3D cold working. The intergranular SCC (IGSCC) susceptibility was the highest in 1D cold worked Alloy while lowest in 2D cold worked Alloy. The IGSCC susceptibility displayed a strong correlation with the grain boundary strain concentration and the grain boundary microstructure.

  • environmentally assisted crack growth in cold worked Alloy 690tt in primary water at low and high temperatures
    Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactors, 2011
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Yoichi Takeda, Juan Hou, Toshio Yonezawa
    Abstract:

    Environmentally assisted crack (EAC) growth in thermally treated Alloy 690 (Alloy 690TT) cold worked one-dimensionally to the thickness reduction of 25% was investigated by crack growth rate testing in the primary water at low and high temperatures. In water at 50 °C and a dissolved hydrogen (DH) of 2.7–2.9 ppm, the test results suggest that the crack growth rate is lower than 2.2×10−9 mm/s at a stress intensity factor of 35 MPa√m. Stress corrosion cracking (SCC) growth with a rate of <1×10−11 m/s was observed in the Alloy in water at temperatures of 320 °C and 340 °C. Over a DH range of 0.37–2.6 ppm, the SCC growth in Alloy 690TT has a similar DH dependence as that in Alloy 600 and its weld metals. The magnitude of the DH dependence, however, is much smaller for Alloy 690TT. In water deaerated by N2 without DH, an extremely low SCC growth rate was observed. Increasing DH in water from 0 ppm to 0.38 ppm caused an active SCC growth, suggesting that hydrogen could promote SCC growth when increasing DH from a very low level. Results of the current work confirmed a general high resistance of 25% cold worked Alloy 690TT to EAC growth in the primary water at both low and high temperatures under moderate stress intensity factors.

Tetsuo Shoji - One of the best experts on this subject based on the ideXlab platform.

  • environmentally assisted crack growth in one dimensionally cold worked Alloy 690tt in primary water
    Corrosion Science, 2012
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Juan Hou, Toshio Yonezawa, Zhaoen Zhang, Fa Huang, Enhou Han
    Abstract:

    Abstract Environmentally assisted crack growth in thermally treated Alloy 690 cold worked one-dimensionally to the thickness reduction of 25% in primary water was investigated. In the water at 50 °C and dissolved hydrogen (DH) of 2.7–2.9 ppm, the Alloy showed a crack growth rate of −9  mm/s at a stress intensity factor of 35 MPa√m. In the water at 340 °C, stress corrosion crack growth rate of −8  mm/s was observed in the Alloy over a DH range of 0.37–2.6 ppm. Further, it was found that hydrogen could promote SCC growth when increasing DH from a very low level.

  • effects of cold working path on strain concentration grain boundary microstructure and stress corrosion cracking in Alloy 600
    Corrosion Science, 2011
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Jiazhen Wang, W Ke
    Abstract:

    Grain boundary microstructure, strain distribution and stress corrosion cracking (SCC) in one dimensional (1D), two dimensional (2D) and three dimensional (3D) cold worked Alloy 600 were investigated. The cold working decreased the annealing twins and increased low angle boundaries. 2D cold working caused lower strain concentration at grain boundaries than 1D and 3D cold working. The intergranular SCC (IGSCC) susceptibility was the highest in 1D cold worked Alloy while lowest in 2D cold worked Alloy. The IGSCC susceptibility displayed a strong correlation with the grain boundary strain concentration and the grain boundary microstructure.

  • environmentally assisted crack growth in cold worked Alloy 690tt in primary water at low and high temperatures
    Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactors, 2011
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Yoichi Takeda, Juan Hou, Toshio Yonezawa
    Abstract:

    Environmentally assisted crack (EAC) growth in thermally treated Alloy 690 (Alloy 690TT) cold worked one-dimensionally to the thickness reduction of 25% was investigated by crack growth rate testing in the primary water at low and high temperatures. In water at 50 °C and a dissolved hydrogen (DH) of 2.7–2.9 ppm, the test results suggest that the crack growth rate is lower than 2.2×10−9 mm/s at a stress intensity factor of 35 MPa√m. Stress corrosion cracking (SCC) growth with a rate of <1×10−11 m/s was observed in the Alloy in water at temperatures of 320 °C and 340 °C. Over a DH range of 0.37–2.6 ppm, the SCC growth in Alloy 690TT has a similar DH dependence as that in Alloy 600 and its weld metals. The magnitude of the DH dependence, however, is much smaller for Alloy 690TT. In water deaerated by N2 without DH, an extremely low SCC growth rate was observed. Increasing DH in water from 0 ppm to 0.38 ppm caused an active SCC growth, suggesting that hydrogen could promote SCC growth when increasing DH from a very low level. Results of the current work confirmed a general high resistance of 25% cold worked Alloy 690TT to EAC growth in the primary water at both low and high temperatures under moderate stress intensity factors.

  • the effect of prior deformation on stress corrosion cracking growth rates of Alloy 600 materials in a simulated pressurized water reactor primary water
    Corrosion Science, 2008
    Co-Authors: Seiya Yamazaki, Yuzuru Ito, Yoichi Takeda, Tetsuo Shoji
    Abstract:

    Abstract The effect of prior deformation on stress corrosion cracking (SCC) growth rates of Alloy 600 materials in a simulated pressurized water reactor primary water environment is studied. The prior deformation was introduced by welding procedure or by cold working. Values of Vickers hardness in the Alloy 600 weld heat-affected zone (HAZ) and in the cold worked (CW) Alloy 600 materials are higher than that in the base metal. The significantly hardened area in the HAZ is within a distance of about 2–3 mm away from the fusion line. Electron backscatter diffraction (EPSD) results show significant amounts of plastic strain in the Alloy 600 HAZ and in the cold worked Alloy 600 materials. Stress corrosion cracking growth rate tests were performed in a simulated pressurized water reactor primary water environment. Extensive intergranular stress corrosion cracking (IGSCC) was found in the Alloy 600 HAZ, 8% and 20% CW Alloy 600 specimens. The crack growth rate in the Alloy 600 HAZ is close to that in the 8% CW base metal, which is significantly lower than that in the 20% CW base metal, but much higher than that in the as-received base metal. Mixed intergranular and transgranular SCC was found in the 40% CW Alloy 600 specimen. The crack growth rate in the 40% CW Alloy 600 was lower than that in the 20% CW Alloy 600. The effect of hardening on crack growth rate can be related to the crack tip mechanics, the sub-microstructure (or subdivision of grain) after cross-rolling, and their interactions with the oxidation kinetics.

Enhou Han - One of the best experts on this subject based on the ideXlab platform.

Toshio Yonezawa - One of the best experts on this subject based on the ideXlab platform.

  • environmentally assisted crack growth in one dimensionally cold worked Alloy 690tt in primary water
    Corrosion Science, 2012
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Juan Hou, Toshio Yonezawa, Zhaoen Zhang, Fa Huang, Enhou Han
    Abstract:

    Abstract Environmentally assisted crack growth in thermally treated Alloy 690 cold worked one-dimensionally to the thickness reduction of 25% in primary water was investigated. In the water at 50 °C and dissolved hydrogen (DH) of 2.7–2.9 ppm, the Alloy showed a crack growth rate of −9  mm/s at a stress intensity factor of 35 MPa√m. In the water at 340 °C, stress corrosion crack growth rate of −8  mm/s was observed in the Alloy over a DH range of 0.37–2.6 ppm. Further, it was found that hydrogen could promote SCC growth when increasing DH from a very low level.

  • environmentally assisted crack growth in cold worked Alloy 690tt in primary water at low and high temperatures
    Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactors, 2011
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Yoichi Takeda, Juan Hou, Toshio Yonezawa
    Abstract:

    Environmentally assisted crack (EAC) growth in thermally treated Alloy 690 (Alloy 690TT) cold worked one-dimensionally to the thickness reduction of 25% was investigated by crack growth rate testing in the primary water at low and high temperatures. In water at 50 °C and a dissolved hydrogen (DH) of 2.7–2.9 ppm, the test results suggest that the crack growth rate is lower than 2.2×10−9 mm/s at a stress intensity factor of 35 MPa√m. Stress corrosion cracking (SCC) growth with a rate of <1×10−11 m/s was observed in the Alloy in water at temperatures of 320 °C and 340 °C. Over a DH range of 0.37–2.6 ppm, the SCC growth in Alloy 690TT has a similar DH dependence as that in Alloy 600 and its weld metals. The magnitude of the DH dependence, however, is much smaller for Alloy 690TT. In water deaerated by N2 without DH, an extremely low SCC growth rate was observed. Increasing DH in water from 0 ppm to 0.38 ppm caused an active SCC growth, suggesting that hydrogen could promote SCC growth when increasing DH from a very low level. Results of the current work confirmed a general high resistance of 25% cold worked Alloy 690TT to EAC growth in the primary water at both low and high temperatures under moderate stress intensity factors.

Yoichi Takeda - One of the best experts on this subject based on the ideXlab platform.

  • environmentally assisted crack growth in cold worked Alloy 690tt in primary water at low and high temperatures
    Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactors, 2011
    Co-Authors: Qunjia Peng, Tetsuo Shoji, Yoichi Takeda, Juan Hou, Toshio Yonezawa
    Abstract:

    Environmentally assisted crack (EAC) growth in thermally treated Alloy 690 (Alloy 690TT) cold worked one-dimensionally to the thickness reduction of 25% was investigated by crack growth rate testing in the primary water at low and high temperatures. In water at 50 °C and a dissolved hydrogen (DH) of 2.7–2.9 ppm, the test results suggest that the crack growth rate is lower than 2.2×10−9 mm/s at a stress intensity factor of 35 MPa√m. Stress corrosion cracking (SCC) growth with a rate of <1×10−11 m/s was observed in the Alloy in water at temperatures of 320 °C and 340 °C. Over a DH range of 0.37–2.6 ppm, the SCC growth in Alloy 690TT has a similar DH dependence as that in Alloy 600 and its weld metals. The magnitude of the DH dependence, however, is much smaller for Alloy 690TT. In water deaerated by N2 without DH, an extremely low SCC growth rate was observed. Increasing DH in water from 0 ppm to 0.38 ppm caused an active SCC growth, suggesting that hydrogen could promote SCC growth when increasing DH from a very low level. Results of the current work confirmed a general high resistance of 25% cold worked Alloy 690TT to EAC growth in the primary water at both low and high temperatures under moderate stress intensity factors.

  • the effect of prior deformation on stress corrosion cracking growth rates of Alloy 600 materials in a simulated pressurized water reactor primary water
    Corrosion Science, 2008
    Co-Authors: Seiya Yamazaki, Yuzuru Ito, Yoichi Takeda, Tetsuo Shoji
    Abstract:

    Abstract The effect of prior deformation on stress corrosion cracking (SCC) growth rates of Alloy 600 materials in a simulated pressurized water reactor primary water environment is studied. The prior deformation was introduced by welding procedure or by cold working. Values of Vickers hardness in the Alloy 600 weld heat-affected zone (HAZ) and in the cold worked (CW) Alloy 600 materials are higher than that in the base metal. The significantly hardened area in the HAZ is within a distance of about 2–3 mm away from the fusion line. Electron backscatter diffraction (EPSD) results show significant amounts of plastic strain in the Alloy 600 HAZ and in the cold worked Alloy 600 materials. Stress corrosion cracking growth rate tests were performed in a simulated pressurized water reactor primary water environment. Extensive intergranular stress corrosion cracking (IGSCC) was found in the Alloy 600 HAZ, 8% and 20% CW Alloy 600 specimens. The crack growth rate in the Alloy 600 HAZ is close to that in the 8% CW base metal, which is significantly lower than that in the 20% CW base metal, but much higher than that in the as-received base metal. Mixed intergranular and transgranular SCC was found in the 40% CW Alloy 600 specimen. The crack growth rate in the 40% CW Alloy 600 was lower than that in the 20% CW Alloy 600. The effect of hardening on crack growth rate can be related to the crack tip mechanics, the sub-microstructure (or subdivision of grain) after cross-rolling, and their interactions with the oxidation kinetics.