Nuclear Power Evaporator Tank Plate Material

Material Properties and Selection:
The mainstream materials are SA533 Gr. B Cl. 2 low-alloy steel or 20MnD5 special steel, with a yield strength ≥450MPa and an impact energy ≥56J at -40℃. The quenching and tempering process forms a bainitic structure, reducing the nil-ductility transition temperature below -73℃. Strict control of P and S content ≤0.008% is implemented to reduce the risk of irradiation embrittlement.

Manufacturing and Testing Requirements:
Must comply with ASME BPVC Section III standards. Cylinder forgings require 100% UT inspection (sensitivity φ1.6mm), and J-factor testing (target value ≤120) and intergranular corrosion testing (ASTM G28 Method A) must be performed. Welding requires a low-hydrogen process, and the interpass temperature must be strictly controlled below 150℃.