Thermal ageing assessment method of cast austenitic stainless steel of CPR1000 nuclear power plant

Abstract

The invention relates to a thermal ageing assessment method of cast austenitic stainless steel of a CPR1000 nuclear power plant. The method comprises the following steps: (a) analyzing the elements of the austenitic stainless steel, and calculating the equivalent chromium content Creq and ferrite content deltac; (b) checking the casting manner and the material mark of the austenitic stainless steel; (c) calculating indoor-temperature Charp impact absorption energy Cv; (d) calculating a breaking tenacity value J1C and a breaking tenacity value Jd when the crack depth is 2.5mm; (e) determining the thermal ageing state of the austenite austenitic stainless steel according to the calculated indoor-temperature Charp impact absorption energy Cv, the breaking tenacity value J1C and the breaking tenacity value Jd when the crack depth is 2.5mm. The thermal ageing sensitivity and the thermal ageing state of the austenitic stainless steel can be assessed and judged by testing the mass content of the specific elements in the austenitic stainless steel based on the casting manner and the material mark; as a result, the problem that the breaking tenacity of the stainless steel cannot be judged in the operation process of the corresponding equipment / part of the CPR1000 nuclear power plant is solved, and a key way is provided for improving the safety of the power plant.

Description

technical field [0001] The invention relates to a thermal aging evaluation method for stainless steel, in particular to a thermal aging evaluation method for cast austenitic stainless steel in a CPR1000 nuclear power plant. Background technique [0002] CPR1000 nuclear power plant primary circuit main pipeline, main pump casing, some valve bodies, etc. are made of cast austenitic stainless steel materials. Research at home and abroad shows that the phenomenon of thermal aging and embrittlement of cast austenitic stainless steel will occur after long-term operation. Typical The effect is that the fracture toughness of the material decreases with increasing operating time. The decrease in fracture toughness will threaten the safety and structural integrity of thermal aging-sensitive equipment, so it is necessary to study a method capable of thermal aging assessment of CPR1000 cast austenitic stainless steel, so as to maintain the structure of thermal aging-related equipment i...

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Problems solved by technology

[0002] CPR1000 nuclear power plant primary circuit main pipeline, main pump casing, some valve bodies, etc. are made of cast austenitic stainless steel materials. Research at home and abroad shows that the phenomenon of thermal aging and embrittlement of cast austenitic stainless steel will occur after long-term operation. Typical The effect is that as the operating time increases, the fracture toughness of the material decreases

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