Nuclear reactor pressure vessel lower seal head with high-durability composite coating structure and preparation method thereof

The invention discloses a nuclear reactor pressure vessel lower seal head and a preparation method thereof. The nuclear reactor pressure vessel lower seal head comprises a lower seal head base body; an antioxidant bottom layer which is formed on at least part of the surface of the outer wall of the lower seal head base body; and a porous metal top layer which is formed on at least part of the surface, away from the outer wall of the lower seal head base body, of the antioxidant bottom layer. The composite coating adopted by the nuclear reactor pressure vessel lower seal head can significantly improve the CHF limit value of the outer wall surface of the lower seal head, and lays a foundation for improving the effectiveness of a high-power reactor IVR. 本发明公开了核反应堆压力容器下封头及其制备方法。该核反应堆压力容器下封头包括：下封头基体；抗氧化底层，所述抗氧化底层形成在所述下封头基体外壁的至少部分表面；以及多孔金属顶层，所述多孔金属顶层形成在所述抗氧化底层远离所述下封头基体外壁的至少部分表面。该核反应堆压力容器下封头所采用的复合涂层可以显著提高下封头外壁表面的CHF限值，为提高大功率反应堆IVR的有效性奠定基础。